Bu çalışma, İsviçre Ulusal Bilim Vakfı (Hibeler n PZ00P2_126430 / 1 ° ve PZ00P2_144595) tarafından desteklenmiştir. Prof C. Leumann minnetle laboratuvar alanı ve ekipman sağlayarak, hem de onun sürekli destek için için kabul edilmektedir. Bayan Sue Knecht verimli tartışmalar için kabul edilmektedir.

1.. Modifiye nükleosit trifosfatın sentezi Seçilen sentetik yaklaşım bu yöntem genellikle güvenilir ve çok az yan ürünlerin (Şekil 1A) 39 yol açar beri Ludwig ve Eckstein tarafından geliştirilen prosedürü takip eder. <ol><li> Iki defa, susuz piridin (2 mi) ile ve daha sonra gece boyunca vakum altında kuru olarak uygun 3&#39;-OAc-korumalı nükleositi (genellikle 0.1 mmol) Coevaporate. Aynı zamanda, bir gece boyunca vakum altında kuru tributilamonyum pirofosfat (0.13 mmol). </li><li> Kuru piridin (0.2 mi) bir minimum nükleositi eritin ve bir birlikte-çözücü olarak, kuru dioksan (0.4 ml) ekleyin. Son olarak, 2-kloro-1 ,3,2-benzodioxaphosphorin-4-on (0.11 mmol) ekleyin ve 45 dakika için oda sıcaklığında reaksiyona izin verir. Not: Bu, özellikle bakım 2-kloro-1 ,3,2-benzodioxaphosphorin-4-on bir reaktif ile alınması gerektiği dikkat çekicidir. Gerçekten de, bir atıl gaz altında bu hava ortam maddesi içinde bir kullanıcının depolamaBurada da ayrışmasını önlemek için yeterli değildir. Bu nedenle, bu ayrışma oluşturulur bu, beyaz bir katı ve kullanım öncesinde kazınıp gerektiğini açıklar. </li><li> Kuru DMF (0.17 mi) içinde tributilamonyum pirofosfat çözeltisi ve taze damıtılmış tributilamin hazırlayın (58 ul; moleküler elekler eklemek hiç). Reaksiyon karışımına (beyaz bir çökelti oluştu fakat hızla kaybolur), elde edilen çözelti ilave edin ve 45 dakika boyunca oda sıcaklığında reaksiyona girmesine izin verir. </li><li> Bir iyot çözeltisi piridin (0.16 mmol) (0.98 mi) ve H2O (20 ul) hazırlayın ve (III) &#39;ün merkezi Pα okside etmek için reaksiyon karışımına ekleyin. Elde edilen koyu renkli çözelti, 30 dakika boyunca oda sıcaklığında karışmaya bırakın. </li><li> I 2 fazlalığını gidermek için NAS 2 O 3,% 10 sulu solüsyonu kullanın. Çözücüyü vakum altında çıkarın (döner buharlaştırıcı içinde su banyosunun sıcaklığı, 30 ° C&#39;nin altında tutulmalıdır). H2O (5 mi) ilave edin ve bir mil izinsiklik trifosfat kısmı hidrolize 30 dakika boyunca oda sıcaklığında beklemeye Karışımı soğutun. </li><li> Bu aşamada, koruyucu gruplar, genellikle (3&#39;-OAc ve nükleobaz yan zincirler üzerindeki grupların, yani) çıkarılır. Sonuç olarak, ham için NH4 OH (2 H, O, 10 ml içinde% 30) ekleyin ve oda sıcaklığında 1.5 saat karışması ve çözücüyü vakum altında çıkarın. </li><li> 2 tüp içine H 2 O ve bölünmüş 2 ml ekleyin. 30 dakika boyunca aseton ve santrifüj (1,000 x g) içinde NaClO 4 arasında bir% 2 çözeltisi 12 ml ilave edilir. Bu prosedür bir kez daha tekrar edilir. Bu çökelme böylece esas olarak takip eden RP-HPLC arıtma basitleştirilmesi, (çökelecektir) trifosfattan sentezinde kullanılan çözücüler ve reaktifler ayrılmaktadır. </li><li> Yağlı tortu, hava ile kurutmadan sonra, (standart prosedürler izlenerek Malzemeler ve Şekil 3&#39;ün de listesi bakınız), ham bir 31 P-NMR spektrumunu kaydetme ve4 ml H2O içinde eritildi Not: Bu sentezleme prosedürü esas olarak tadil edilmiş deoksinükleosit trifosfat jenerasyonu üzerinde odaklanırken, çok benzer bir prosedür, (sadece, 3&#39;-bis-O-asile ön-maddeleri 2 &#39;kullanılarak) kendi RNA meslektaşları için uygulanabilir. </li></ol> 2. Modifiye nükleosid trifosfatlar HPLC ile saflaştırılması <ol><li> Trietilamonyum bikarbonat (Teab) bir 1 M stok çözeltisinin hazırlanması: 40 <ol><li> Damıtılmış ve süzüldü H 2 O&#39;dan ≈ 600 ml trietilamin 1 mol (139 mi) ihtiva eden bir çözelti hazırlayın </li><li> Kabarcık CO2 (kuru buz ve bir gaz kabarcık ile) kuvvetli karıştırma altında çözelti içine 7.6 bir pH (bu, en az 10 saat sürer) ulaşana kadar. Bu stok çözeltisi, bir aya kadar buzdolabında muhafaza edilebilir. </li></ol></li><li> Arıtma: <ol><li> Ultra saf su içinde 50 mM Teab 2 L (eluent A) a: 1 M stok çözelti hazırlayın iki geçici belleknd 50% MeCN (eluent B) 50 mM Teab 1 L. Her iki yıkama sıvıları vakum altında ve 20 dakika boyunca karıştırıldıktan Degas (dikkat ve özen gaz alma sırasında CO2 kaldırarak pH değerini değiştirmek için o kadar olarak gereklidir). </li><li> 300 ul damıtılmış H2O içinde ham trifosfat 10 ul eritilerek, bir analitik numune hazırlayın ve bir yarı-hazırlayıcı RP kolonu (C18) ile donatılmış ve değişen bir gradyan kullanılarak, bir HPLC sistemi içine enjekte edilir, 40 dakika içinde% 0-100 B (Şekil 4). Trifosfat R t (genellikle kromatogramda ana pik olan) ve (a biraz daha düşük R t vardır) difosfat göre HPLC programı ayarlayın. Bu koşulları ve bazı difosfat içerebilir ilk fraksiyonlar kaldırarak kullanılarak ham karışım arındırın. </li><li> Ürünü içeren tüm fraksiyonlar birleştirilir ve dondurularak kuru (istenmeyen diphosph için hidrolizini minimuma indirmek amacıyla, döner buharlaştırıcı üzerinde buharlaştırma tercih edilir) yedik. (Saflaştırma maddesi kalıntısı trietilamin çıkarmak için) ultra-saf su ile bir kaç kez Coevaporate. NMR ile trifosfat saflığını standart protokoller uygulanmasıyla (1H ve31P NMR her ikisi) ve MALDI-TOF (bkz. Şekil 5) değerlendirmek. Bu protokolün uygulanması ile elde edilen tipik verimler, tipik olarak alt tabakaya bağlı olarak,% 30-70 aralığı içinde yer alır. </li></ol></li></ol> 3. Primer Uzatma Reaksiyonları ve TdT Polimerizasyon <ol><li> Primerin 5&#39;-uç etiketleme <ol><li> Uygun primerin 30 pmol karıştırın (örneğin P1, Malzeme Listesi) 10x polinükleotid kinaz (PNK) tamponu, γ-[32P]-ATP, PNK 1 ul ve GKD 2 O 3 ul için (4 ul 40 ul toplam reaksiyon hacmi). 30 dakika boyunca 37 ° C&#39;de inkübe edin ve reaksiyon karışımı daha sonra kinaz (70 ° C &#39;de 10 dakika) ısı devre dışı bırakır. </li><li> Etiketleme reaksiyonu sırasında hazırlamaksilanize cam yünü ile 1 ml pipet takıp ve G10 çözeltisi (GKD 2 O içinde% 10, otoklav) ile ucu doldurarak bir Sephadex G10 kolonu. Spin ve 500 ul GKD 2 O ve 50 ul GKD 2 O. ile son bir kez yıkama ile üç kez yıkayın (Serbest radyoaktif etiket çıkarmak için) G10 boyunca reaksiyon karışımının çalıştırın. </li><li> Jel (PAGE% 20) radyo-etiketli primer arındırmak ve ezmek uygulanmasıyla kurtarmak ve 15 için 72 ° C&#39;de% 1 LiClO 4 ve 1 mM 3 NEt (pH 8) ihtiva eden sulu bir çözelti ile 500 ul bir yöntem (yani, bir elüsyon emmek dk). Çökelti etanol ve G10 elüt oligonükleotid tuzunun giderilmesi. </li></ol></li><li> Primer uzatma reaksiyonu <ol><li> Tavlama 1 radyo-etiketli primer P1 pmol, 10 pmol primer P1 ve 10 (kullanılacak polimerazın tedarikçi tarafından sağlanan) 10x reaksiyon tamponu içinde şablon T1 (Malzeme Listesi) pmol t yerleştirerekUbe, sıcak (90-95 ° C) su içinde ve yavaş yavaş (45 dakika boyunca), oda sıcaklığına kadar soğuması için izin verilir. </li><li> Buz üzerinde tüp koyun ve (sırayla) dNTP kokteyl ekleyin (değiştirilmiş veya her ikisini de içeren, doğal trifosfatı, 100 uM son konsantrasyon) ve DNA polimeraz 1 U (ekzo (Vent - Klenow, Pwo ya da 9 ° N,) m) ve 20 ul toplam reaksiyon hacmi için, su () ile tam. (-) Kullanılıyor Vent (ekzo 30 dakika boyunca, örneğin 60 ° C) enzim en uygun çalışma sıcaklığında inkübe edin. </li><li> Durdurma solüsyonu (formamid (% 70), etilendiamintetraasetik asit (EDTA, 50 mM), bromofenol mavisi (% 0.1), ksilen siyanol (% 0.1)) 20 ul ekle örnekleri (95 ° C, 5 dakika) ısı, soğuk aşağı (0 ° C), ve denatüre poliakrilamid jel elektroforezi ile çözmek. Fosforimagere canlandırın. </li></ol></li><li> TdT polimerizasyon <ol><li> Tek şeritli 7 pmol seyreltin, Etiketlenmemiş primer P2 (Malzeme listesi), 1 ul tampon maddesi TdT 10x in radyo-etiketli primerden 1 pmol. </li><li> Buz üzerinde tüp koyun ve (sırayla) (10 ve 200 uM arasında bulunan uygun bir konsantrasyonda) dNTP kokteyl ile TdT polimeraz (4 U) ekleyin. 1 saat boyunca 37 ° C&#39;de inkübe edilir. Stop solüsyonu 10 ul ekleyin örnekleri (95 ° C, 5 dakika) ısıtın, (0 ° C) soğumaya bırakın ve (SAYFA 15%) denatüre poliakrilamid jel elektroforezi ile çözmek. Fosforimagere canlandırın. </li></ol></li></ol> 4. Modifiye nükleosid trifosfatlar ile PCR <ol><li> Her ikisi de ileri 8 pmol karıştırın ve amplifiye edilecek şablonun 0.5 pmol ile geri primerler. 10x reaksiyon tamponu ve (200 uM son konsantrasyon) dNTP kokteyl ilave edin ve buz üzerinde tüp koydu. 20 ul bir son hacme ulaşmak için 1 U DNA polimeraz ve H2O ile birlikte ekleyin. PCR şişenin içine karışımı aktarın ve 30 PCR döngüleri yürütmek.</li><li> 2x sakaroz yükleme tamponu 6 ul 6 ul seyreltin ve elektroforezi (etidyum bromür ile boyanmış) agaroz ile% 2 çözmek. Fosforimagere canlandırın. </li></ol>

Çıkar çatışması ilan etti.

Nükleik asitlerin içine modifikasyonların dahil antisense ve antijen maddelerin geliştirilmesi 42,43, etiketleme ve oligonükleotidlerin 41 fonksiyonel etiketleme de dahil olmak üzere pek çok pratik uygulamalar için ilgi çekici olan ve genetik alfabe 44-46 genişletmek çabalarında. Kimyasal değişiklikler ve fonksiyonel gruplar genellikle, standart ve otomatik katı faz sentezi protokolleri uygulanmasıyla nükleik asitler dahil edilir. Bununla birlikte, fosforamidit yapı ta?...

<html> 5&#39;-nükleosit trifosfatlar ((d) NTP&#39;ler) evrensel enerji birimi olmaktan hücre metabolizması düzenleyicileri kadar sayısız işlem ve fonksiyonların katılan önemli bir biyomoleküllerin bir sınıfını temsil eder. Bu temel biyolojik dönüşümler rollerine ilave olarak, bunların modifiye edilmiş oligonükleotidlerin muadilleri olarak işlevsel grupların sokulması için bir çok yönlü ve hafif bir platform, güzel bir şekilde, genellikle 1,2 uygulandığı bir otomasyonlu katı faz sentezini tamamlar bir yöntem olarak gelişmiş var. Gerçekten de, (d) NTP&#39;ler RNA ve DNA polimerazların 3 alt-tabakalar için, amino asitler 4-13, boronik asitler 14,15, nornbornene 16, diamondoid benzeri kalıntıları 17 için, yan zincirler de dahil olmak üzere işlevsel grupların zenginliği olarak hareket edebilir Resim organik kataliz 18, safra asitleri 19 ve hatta 20 oligonükleotidler oligonükleotid içine sokulabilir. _content &quot;&gt; nükleik asitlerin işlevsellik için uygun bir vektör temsil ötesinde, modifiye edilmiş dNTP, SELEX ve modifiye katalitik nükleik asit 21-30 ve çeşitli pratik uygulamalar için 10 aptamers oluşturulması için in vitro seçimi diğer ilgili kombinasyon yöntemlerinde meşgul olabilir 31-36. modifiye edilmiş dNTP&#39;ler polimerizasyonu tarafından ortaya olan ilave Yan zincirler, bir seçim deney sırasında incelenmiş ve nükleik asitlerin 37&#39;nin oldukça kötü fonksiyonel cephanelik takviye edilebilir kimyasal alanını artırmak düşünülmektedir. Ancak, bu rağmen çekici özellikleri ve sentetik ve analitik yöntemlerin her ikisi de gelişmesinde yapılan son ilerlemeler, evrensel uygulanabilir ve yüksek verimli bir prosedür modifiye nükleosit trifosfat 2,38 işçiliği ihtiyaç vardır. Bu mevcut protokolün amacı, (bazen) karmaşık prosedürleri önde gelen t içine ışık tutmaktıro sentezi ve bu aktive edilmiş yapı blokları (Şekil 1 B) biyokimyasal karakterizasyonu. Özel vurgu genellikle bulmak zor ya da deneysel bölümlerde bulunmadığına ancak saf (d) NTP&#39;ler izolasyonu (Şekil 1) yol açan sentetik yolunun başarılı bir şekilde tamamlanması için henüz çok önemli olan tüm sentetik ayrıntılar verilecektir.

<table border="0" cellpadding="0" cellspacing="0" width="799">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">tributylammonium pyrophosphate&#160;</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td style="width:143px;">P8533</td>
			<td style="width:215px;">Hygroscopic solid, keep under Ar</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2-chloro-1,3,2-benzodioxaphosphorin-4-one&#160;</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">324124</td>
			<td>Moisture sensitive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Pyridine</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">82704</td>
			<td>Under molecular sieves</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Dioxane</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">296309</td>
			<td>Under molecular sieves</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">dimethylformamide (DMF)</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">40248</td>
			<td>Under molecular sieves</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">Acetonitrile&#160;</td>
			<td style="width:109px;">Fisher Scientific</td>
			<td style="width:143px;"></td>
			<td>HPLC grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Triethylamine</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">90342</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Tributylamine</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">90781</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:333px;">ddH2O</td>
			<td style="width:109px;">Milli-Q</td>
			<td style="width:143px;"></td>
			<td>deionized and purified water, autoclaved in the presence of Diethylpyrocarbonate (DEPC)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Diethylpyrocarbonate (DEPC)</td>
			<td style="width:109px;">Sigma Aldrich</td>
			<td align="right" style="width:143px;">159220</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="86">
			<td height="86" style="height:86px;width:333px;">D2O</td>
			<td style="width:109px;">Cambridge Isotope Laboratories, Inc.</td>
			<td style="width:143px;">DLM-4-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Biochemical reagents</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">g-[32P]-ATP</td>
			<td style="width:109px;">Hartmann Analytics</td>
			<td style="width:143px;">FP-301</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Natural dNTPs</td>
			<td style="width:109px;">Promega</td>
			<td style="width:143px;">U1420</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:333px;">Vent (exo-) DNA polymerase</td>
			<td style="width:109px;">NEB</td>
			<td style="width:143px;">M0257S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">DNA polymerase I, Large (Klenow) Fragment</td>
			<td style="width:109px;">NEB</td>
			<td style="width:143px;">MO210S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:333px;">9&#176;Nm DNA polymerase</td>
			<td style="width:109px;">NEB</td>
			<td style="width:143px;">MO260S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Terminal deoxynucleotidyl Transferase (TdT)</td>
			<td style="width:109px;">Promega</td>
			<td style="width:143px;">M828A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Pwo DNA polymerase</td>
			<td style="width:109px;">Peqlab</td>
			<td style="width:143px;">01 01 5010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">T4 PNK</td>
			<td style="width:109px;">Thermo Scientific</td>
			<td>EK0032</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Acrylamide/bisacrylamide (19:1, 40%)</td>
			<td style="width:109px;">Serva</td>
			<td align="right" style="width:143px;">10679.01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">Agarose</td>
			<td style="width:109px;">Apollo Scientific</td>
			<td style="width:143px;">BIA1177</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">G10 Sephadex</td>
			<td style="width:109px;">Sigma</td>
			<td style="width:143px;">G10120</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">Urea</td>
			<td style="width:109px;">Apollo Scientific</td>
			<td style="width:143px;">BIU4110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Equipment</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">Jupiter semi-preparative RP-HPLC column (5m C18 300&#197;)</td>
			<td style="width:109px;">Phenomenex</td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Gene Q Thermal Cycler</td>
			<td style="width:109px;">Bioconcept</td>
			<td style="width:143px;">BYQ6042E</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">PCR vials</td>
			<td style="width:109px;">Bioconcept</td>
			<td style="width:143px;">3220-00</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:333px;">HPLC system</td>
			<td style="width:109px;">Amersham Pharmacia Biotech</td>
			<td style="width:143px;"></td>
			<td>&#196;kta basic 10/100</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Oligonucleotides</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">All oligonucleotides were purchased from Microsynth and purified by PAGE</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">5&#39;-CAAGGACAAAATACCTGTATTCCTT P1</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:333px;">5&#39;-GACATCATGAGAGACATCGCCTCTGGGCTAAT-AGGACTACTTCTAATCTGTAAGAGCAGATCCCTGG-ACAGGCAAGGAATACAGGTATTTTGTCCTTG T1</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">5&#39;-GAATTCGATATCAAG P2</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;"></td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:333px;">More information on experimental procedures and equipment can be found in the following articles:</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:333px;">Chem. Eur. J. 2012, 18, 13320 &#8211; 13330</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:333px;">Org. Biomol. Chem. 2013, DOI: 10.1039/C3OB40842F.</td>
			<td style="width:109px;"></td>
			<td style="width:143px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

nucleoside triphosphates - from synthesis to biochemical characterization

Bir kimyasal fonksiyonelliğin getirilmesi için geleneksel bir strateji olgunlaşmamış zincirine uygun şekilde modifiye edilmiş fosforamidit öncüleri eklenmesi ile katı-faz sentezi kullanılmasıdır. Ancak, oldukça kısa dizilere sentezi ve sınırlama sırasında kullanılan koşullar, bu yöntemin uygulanabilirliğinin engellemektedir. Öte yandan, modifiye edilmiş nükleosit trifosfatlar nükleik asitler, pratik bir uygulama geniş palette modifiye nükleik asitlerin kullanımı için bir yol açıyor bir strateji içine çok sayıda işlevsel grupların sokulması için hafif kullanılmıştır yapı taşları aktive edilir Böyle ribozimlerin ve DNAzimler fonksiyonel etiketleme ve nesil gibi. En önemli sorunlardan biri, bu nükleosid analoglarının izolasyonu ve karakterizasyonu yol açan metodoloji karışıklık bulunur. Bu ekran yazıda, thes sentezi için detaylı bir protokol mevcute fosfor (III) bazlı reaktifler kullanılarak değiştirilmiş analoglarıdır. Buna ek olarak, onların biyokimyasal karakterizasyonu için prosedür astar uzatma reaksiyonları ve TdT kuyruklanmasız polimerizasyon özel bir vurgu ile, ifşa edilir. Bu ayrıntılı protokol modifiye dNTP işçiliği ve kimyasal biyolojide bunların daha sonraki kullanım için faydalı olacaktır.

Bu nükleik asitler 41 içine işlevsel grupların bir çok dizi kolay sokulması için izin verirse, modifiye nükleosit trifosfatlar sentetik hedefleri çekici edilir. Bununla birlikte, bu aktif yapı bloklarının izolasyonu ve karakterizasyonu genellikle zor olduğu ortaya çıkar. Sonuç olarak, bu tarifnamede gösterilen sonuçlar, belirtilen sentetik ve biyokimyasal işlemler (Şekil 1 B) içinde çeşitli adımları için bir yardım el sağlamak düşünülmektedir. <p class="jov...

Watch this Scientific Journal Video about Nucleoside Triphosphates - From Synthesis to Biochemical Characterization at JoVE.com

Nucleoside Triphosphates - From Synthesis to Biochemical Characterization

Burada tarif edilen protokol modifiye nükleosit trifosfat yol açan karmaşık güzergah yolunda çok sayıda engeller açıklamak ve kesintiye uğratmak için amaçlamaktadır. Dolayısıyla, bu protokol bu aktive bina bloklarının sentezini ve pratik uygulamalar için onların durumu hem de kolaylaştırır.

Nükleosid trifosfatlar - sentezinden Biyokimyasal Karakterizasyonu için

The  traditional strategy for the introduction of chemical functionalities is the  use of solid-phase synthesis by appending suitably modified ...

nucleoside-triphosphates-from-synthesis-to-biochemical

Research

JoVE Journal

Chemistry

17.0K Görüntüleme.  University of Bern.  Burada tarif edilen protokol modifiye nükleosit trifosfat yol açan karmaşık güzergah yolunda çok sayıda engeller açıklamak ve kesintiye uğratmak için amaçlamaktadır. Dolayısıyla, bu protokol bu aktive bina bloklarının sentezini ve pratik uygulamalar için onların durumu hem de kolaylaştırır. 

Video: Nucleoside Triphosphates - From Synthesis to Biochemical Characterization

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid phase by using combinatorial chemistry. One of the most well studied classes of peptidomimetics is peptoids. Peptoids are easy to synthesize and have been shown to be proteolysis-resistant and cell-permeable. Over the past decade, many useful protein ligands have been identified through screening of peptoid libraries. However, most of the ligands identified from peptoid libraries do not display high affinity, with rare exceptions. This may be due, in part, to the lack of chiral centers and conformational constraints in peptoid molecules. Recently, we described a new synthetic route to access peptide tertiary amides (PTAs). PTAs are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. With side chains on both &#945;-carbon and main chain nitrogen atoms, the conformation of these molecules are greatly constrained by sterical hindrance and allylic 1,3 strain. (Figure 1) Our study suggests that these PTA molecules are highly structured in solution and can be used to identify protein ligands. We believe that these molecules can be a future source of high-affinity protein ligands. Here we describe the synthetic method combining the power of both split-and-pool and sub-monomer strategies to synthesize a sample one-bead one-compound (OBOC) library of PTAs.

Peptide tertiary amides (PTAs) are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. Here we describe a synthetic method which combines&#160;both split-and-pool and sub-monomer strategies to synthesize a one-bead one-compound library of PTAs.

Split-ve-havuz Sentezi ve Peptit Tersiyer Amid Kütüphanesi Karakterizasyonu

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid ...

Kimya

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

Fonksiyonlu Sentezi ve Karakterizasyonu Metal-organik Altyapıları

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups and scaffolds. Traditional methods for the preparation of ynones are associated with drawbacks including harsh conditions, multiple purification steps, and the presence of unwanted byproducts. An alternative method for the straightforward preparation of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts is described herein. The adoption of organotrifluoroborate salts as an alternative to organometallic reagents for the formation of new carbon-carbon bonds has a number of advantages. Potassium organotrifluoroborate salts are shelf stable, have good functional group tolerance, low toxicity, and a wide variety are straightforward to prepare. The title reaction proceeds rapidly at ambient temperature in the presence of a Lewis acid without the exclusion of air and moisture. Fair to excellent yields may be obtained via reaction of various aryl and alkyl acid chlorides with alkynyltrifluoroborate salts in the presence of boron trichloride.

The goal of this manuscript is to demonstrate a straightforward method for the preparation of ynones from acyl chloride and potassium alkynyltrifluoroborate salt starting materials. The one-pot reaction proceeds rapidly in the presence of boron trichloride without exclusion of air and moisture.

Asil klorür ve potasyum Alkynyltrifluoroborate Tuzlarından Ynones Metal içermeyen sentezi

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups ...

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Herein we report the synthesis of a tridentate phosphine ligand N(CH2PPh2)3 (N-triphosPh) (1) via a phosphorus based Mannich reaction of the hydroxylmethylene phosphine precursor with ammonia in methanol under a nitrogen atmosphere. The N-triphosPh ligand precipitates from the solution after approximately 1 hr of reflux and can be isolated analytically pure via simple cannula filtration procedure under nitrogen. Reaction of the N-triphosPh ligand with [Ru3(CO)12] under reflux affords a deep red solution that show evolution of CO gas on ligand complexation. Orange crystals of the complex [Ru(CO)2{N(CH2PPh2)3}-&#954;3P] (2) were isolated on cooling to RT. The 31P{1H} NMR spectrum showed a characteristic single peak at lower frequency compared to the free ligand. Reaction of a toluene solution of complex 2 with oxygen resulted in the instantaneous precipitation of the carbonate complex [Ru(CO3)(CO){N(CH2PPh2)3}-&#954;3P] (3) as an air stable orange solid. Subsequent hydrogenation of 3 under 15 bar of hydrogen in a high-pressure reactor gave the dihydride complex [RuH2(CO){N(CH2PPh2)3}-&#954;3P] (4), which was fully characterized by X-ray crystallography and NMR spectroscopy. Complexes 3 and 4 are potentially useful catalyst precursors for a range of hydrogenation reactions, including biomass-derived products such as levulinic acid (LA). Complex 4 was found to cleanly react with LA in the presence of the proton source additive NH4PF6 to give [Ru(CO){N(CH2PPh2)3}-&#954;3P{CH3CO(CH2)2CO2H}-&#954;2O](PF6) (6).

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Ruthenium phosphine complexes are widely used for homogeneous catalytic reactions such as hydrogenations. The synthesis of a series of novel tridentate ruthenium complexes bearing the N-triphos ligand N(CH2PPh2)3 is reported. Additionally, the stoichiometric reaction of a dihydride Ru&#8211;N-triphos complex with levulinic acid is described.

Rutenyum bir Serisi Sentezi, Karakterizasyonu ve Tepkime<em&gt; K</em&gt; -triphos<sup&gt; Ph</sup&gt; Kompleksi

Herein we report the synthesis of a tridentate phosphine ligand N(CH2PPh2)3 (N-triphosPh) (1) via a phosphorus based Mannich reaction of the ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

Sentezi, Karakterizasyonu ve Hibrid Au / CdS ve Au / ZnS Çekirdek / Shell Nanopartiküller işlevselleştirilmesi

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Supramoleküler Kolloidlerin Sentezi ve Karakterizasyonu

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

HPLC-based Assay to Monitor Extracellular Nucleotide/Nucleoside Metabolism in Human Chronic Lymphocytic Leukemia Cells

This method describes a sensitive, specific, reliable and reproducible reverse phase high-performance liquid chromatography (RP-HPLC) assay developed and validated for the quantification of extracellular purine nucleotides and nucleosides produced by purified chronic lymphocytic leukemia (CLL) cells under different culture conditions. The chromatographic separation of adenosine 5&#39;-monophosphate (AMP), adenosine (ADO) and inosine (INO) is performed at RT on a silica-based, reversed-phase column that is used for polar compound retention. The method includes a binary mobile phase, which consists of 7 mM ammonium acetate and acetonitrile with a flow rate of 1.00 ml/min. The eluates are monitored using a Photodiode Array UV detector set at 260 nm. A standard calibration curve is generated to calculate the equation for the analytical quantification of each purine compound. System control, data acquisition and analysis are then performed. Applying this protocol, AMP, INO and ADO elute at 7, 11 and 11.9 min, respectively, and the total run time for each sample is 20 min. This protocol may be applied to different cell types and cell lines (both suspension and adherent), using culture media as matrix. The advantages are easy and fast sample preparation and the requirement of a small amount of supernatant for analysis. Furthermore, the use of a serum-free medium allows skipping the protein precipitation step with acetonitrile that impacts the final concentration of purine compounds. One of the limitations of the method is the requirement of the equilibration column run before each single sample run, making the total run time of the experiment longer and preventing high throughput screening applications.

The protocol described here represents an easy and reproducible method that employs reverse phase high-performance liquid chromatography (RP-HPLC) to measure purine metabolism on chronic lymphocytic leukemia (CLL) cells cultured under different conditions.

HPLC tabanlı Testi İnsan Kronik Lenfositik Lösemi Hücrelerinde Ekstraselüler Nükleotid / Nükleozid Metabolizması Monitör

This method describes a sensitive, specific, reliable and reproducible reverse phase high-performance liquid chromatography (RP-HPLC) assay developed and ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

Tek Molekül Düzeyde Halkalı Polimerlerin Sentezi ve eritin Devlet Onların Pasif Hareket Karakterizasyonu

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Synthesis and Characterization of Fe-doped Aluminosilicate Nanotubes with Enhanced Electron Conductive Properties

The goal of the protocol is to synthesize Fe-doped aluminosilicate nanotubes of the imogolite type with the formula (OH)3Al2-xFexO3SiOH. Doping with Fe aims at lowering the band gap of imogolite, an insulator with the chemical formula (OH)3Al2O3SiOH, and at modifying its adsorption properties towards azo-dyes, an important class of organic pollutants of both wastewater and groundwater.
Fe-doped nanotubes are obtained in two ways: by direct synthesis, where FeCl3 is added to an aqueous mixture of the Si and Al precursors, and by post-synthesis loading, where preformed nanotubes are put in contact with a FeCl3&#8226;6H2O aqueous solution. In both synthesis methods, isomorphic substitution of Al3+ by Fe3+ occurs, preserving the nanotube structure. Isomorphic substitution is indeed limited to a mass fraction of ~1.0% Fe, since at a higher Fe content (i.e., a mass fraction of 1.4% Fe), Fe2O3 clusters form, especially when the loading procedure is adopted. The physicochemical properties of the materials are studied by means of X-ray powder diffraction (XRD), N2 sorption isotherms at -196 &#176;C, high resolution transmission electron microscopy (HRTEM), diffuse reflectance (DR) UV-Vis spectroscopy, and &#950;-potential measurements. The most relevant result is the possibility to replace Al3+ ions (located on the outer surface of the nanotubes) by post-synthesis loading on preformed imogolite without perturbing the delicate hydrolysis equilibria occurring during nanotube formation. During the loading procedure, an anionic exchange occurs, where Al3+ ions on the outer surface of the nanotubes are replaced by Fe3+ ions. In Fe-doped aluminosilicate nanotubes, isomorphic substitution of Al3+ by Fe3+ is found to affect the band gap of doped imogolite. Nonetheless, Fe3+ sites on the outer surface of nanotubes are able to coordinate organic moieties, like the azo-dye Acid Orange 7, through a ligand-displacement mechanism occurring in an aqueous solution.

Here, we present a protocol to synthesize and characterize Fe-doped aluminosilicate nanotubes. The materials are obtained by either sol-gel synthesis upon addition of FeCl3&#8226;6H2O to the mixture containing the Si and Al precursors or by post-synthesis ionic exchange of preformed aluminosilicate nanotubes.

Geliştirilmiş Elektron İletken özellikleri ile Fe-katkılı Alüminosilikat Nanotüpler Sentezi ve Karakterizasyonu

The goal of the protocol is to synthesize Fe-doped aluminosilicate nanotubes of the imogolite type with the formula (OH)3Al2-xFexO3SiOH. Doping with Fe ...

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine

Amino alcohols are versatile compounds with a wide range of applications. For instance, they have been used as chiral scaffolds in organic synthesis. Their synthesis by conventional organic chemistry often requires tedious multi-step synthesis processes, with difficult control of the stereochemical outcome. We present a protocol to enzymatically synthetize amino alcohols starting from the readily available L-lysine in 48 h. This protocol combines two chemical reactions that are very difficult to conduct by conventional organic synthesis. In the first step, the regio- and diastereoselective oxidation of an unactivated C-H bond of the lysine side-chain is catalyzed by a dioxygenase; a second regio- and diastereoselective oxidation catalyzed by a regiodivergent dioxygenase can lead to the formation of the 1,2-diols. In the last step, the carboxylic group of the alpha amino acid is cleaved by a pyridoxal-phosphate (PLP) decarboxylase (DC). This decarboxylative step only affects the alpha carbon of the amino acid, retaining the hydroxy-substituted stereogenic center in a beta/gamma position. The resulting amino alcohols are therefore optically enriched. The protocol was successfully applied to the semipreparative-scale synthesis of four amino alcohols. Monitoring of the reactions was conducted by high performance liquid chromatography (HPLC) after derivatization by 1-fluoro-2,4-dinitrobenzene. Straightforward purification by solid-phase extraction (SPE) afforded the amino alcohols with excellent yields (93% to &#62;95%).

Chiral amino alcohols are versatile molecules for use as scaffolds in organic synthesis. Starting from L-lysine, we synthesize amino alcohols by an enzymatic cascade reaction combining diastereoselective C-H oxidation catalyzed by dioxygenase followed by cleavage of the carboxylic acid moiety of the corresponding hydroxyl amino acid by a decarboxylase.

Enzimatik Cascade reaksiyonlardan L-lizin Amino kiral alkoller sentezi için

Amino alcohols are versatile compounds with a wide range of applications. For instance, they have been used as chiral scaffolds in organic synthesis. ...