Name: solid-phase synthesis of [4.4] spirocyclic oximes
Uploaded: 2019-02-06T13:00:00
Description: Watch this Scientific Journal Video about Solid-phase Synthesis of [4.4] Spirocyclic Oximes at JoVE.com

Bu eser fakülte Araştırma Konseyi bir hibe için K.S. Huang (Azusa Pasifik Üniversitesi - ABD) tarafından finanse edildi. CR Drisko John Stauffer burs ve Gencarella Lisans Araştırma Bursu bir alıcı var. S.A. Griffin, kimya ve Biyoloji bölümü bir S2S lisans araştırma bursu aldı.
<img alt="Image 1" src="/files/ftp_upload/58508/58508img1.jpg">
(Soldan sağa) yazarlar Cody Drisko, Dr. Kevin Huang ve Silas Griffin deneyler yaptı ve el yazması hazırladı. Cody Drisko John Stauffer adam ve Gencarela araştırma bursu bir alıcı var. Silas S2S Azusa Pasifik Üniversitesi araştırma görevlisi olduğunu. Dr. Kevin Huang araştırma danışmanlık sağlanmış ve Azusa Pasifik Üniversitesi fakülte Araştırma Konseyi Grant bir alıcı.

Dikkat: Lütfen ilgili tüm malzeme güvenlik bilgi formları (MSDS) kullanmadan önce danışın. Birkaç bu immobilizasyonu kullanılan kimyasalların akut toksik ve kanserojen vardır. Lütfen aşağıdaki reaksiyonlar (duman hood ve IR ve NMR Spektrometreler) Mühendislik kontrolleri ve kişisel koruyucu ekipman kullanımı da dahil olmak üzere, yerine getirirken tüm uygun güvenlik uygulamaları kullanın (koruyucu gözlük, eldiven, önlük, tam uzunlukta pantolon, ve kapalı-toe ayakkabı).
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Tipik bir REM bağlayıcı/katı-faz sentetik strateji, sağlam destek bir amin sürümünden önce içinde iletişim kuralı394 bölümde açıklandığı gibi bir dördüncül amonyum tuz formu için önemlidir. Trisiklik sistem ve hantal R2 gruplar (Benzil ve Oktil halojenürlerden) steric engel nedeniyle, sadece küçük etmen reaktifler (metil ve alil halojenürlerden) Bu reaksiyon46de yararlanılabilir. Ayrıca ve daha büyük, steric reaktifler, kullanım?...

Son derece functionalized spirocyclic heterocycles biyolojik sistemleri1bir dizi kullanarak son keşifler rağmen hala kolay kendi üretimi için uygun bir yol gereklidir. Böyle sistemleri ve bu heterocycles kullanımları içerir: MDM2 inhibisyonu ve diğer antikanser aktivite2,3,4,5, enzim inhibisyonu6,7,8 , antibiyotik aktivite9,10,10,11,12, DNA için bağlama enetioselektif etiketleme floresan probları13,14, 15 ve16, yanı sıra çok sayıda potansiyel uygulamalar therapeutics17,18,19hedefleme RNA. Bu heterocycles için artan bir talep ile geçerli edebiyat hangi sentetik en iyi yoludur hakkında bölünmüş kalır. Heterocycles20,21, karmaşık intramolecular düzenlemeler22,23çeşitli malzemeler başlangıç olarak isatin ve isatin türevleri bu sorun modern sentetik yaklaşımlar kullanmak ,24,25, Lewis asit1,26,27 veya geçiş metal kataliz17,28,29, 30veya asimetrik işlemleri31. Bu yordamları belirli spirocyclic oximes sınırlı işlevler ile Üreten bir başarı olmuştur iken, bir kütüphane ile yüksek diastereoselectivity moleküllerinin üretmek için sentetik bir strateji nispeten daha az keşfedilmiş32olmuştur.
Burada sunulan teknik bu moleküller ilgi iyi anlaşılmış sentetik teknikleri çok sayıda tandem kullanarak oluşturulan gösterir. Bir REM bağlayıcı ve intramolecular silyl nitronate-organik cycloaddition (ISOC) kullanarak sağlam bir destek molekül sentezi ile başlayan, önerilen yolu bırakarak trisiklik bir sistemde kesilmesinin bond ile karakterize bir doğrusal olmayan yol dağıtır bir Son derece functionalized heterocycle. REM halkalı, onların kolaylık ve geri dönüşüm, bilinen üçüncül aminler33sentezlemek için sağlam bir destek kullanmak. REM bağlayıcı üzerinden basit arıtma için akredite arıtma kolaylığı nedeniyle, bu katı fazlı sentez teknik bilim adamları burada kullanılan bir geri dönüşümlü ve traceless bağlayıcı ile sağlar. Reaksiyon tamamlandıktan sonra REM bağlayıcı yeniden oluşturulur ve birden çok kez yeniden kullanılabilir. Çok katı fazlı halkalı, ek ürün ve polimer arasında ayırt edilemez34,35noktasıdır, REM bağlayıcı de traceless çünkü. Ayrıca ISOC tepki, pirolidin oximes36,37sentezinde yararlı iyi okudu ve anlaşılır. Belki de daha çok bilinen adıyla 1,3-dipolar cycloaddition heterocycles yüksek diastereoselectivity38,39,40,41,42 ile bir dizi bu tepkiler formu , 43 , 44 , 45. spirocyclic moleküllerin sentezi son derece diastereoselective ürün verimleri için değiştirilmiş REM birleştiğinde ISOC tekniği kullanarak. Burada, biz iki iyi anlaşılmış yolları ve hazır başlangıç malzemeleri birleştirerek yeni bir sentetik yaklaşım kullanarak spirocyclic oximes verimli üretim raporu.

<table>
	<tbody>
		<tr>
			<td>Chemicals</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>REM Resin</td>
			<td>Nova Biochem</td>
			<td>8551010005</td>
			<td>Solid Polymer Support; 1.1 mmol/g loading</td>
		</tr>
		<tr>
			<td>Furfurylamine</td>
			<td>Acros Organics</td>
			<td>119800050</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Dimethylformamide (DMF)</td>
			<td>Sigma-Aldrich</td>
			<td>227056</td>
			<td>Solvent</td>
		</tr>
		<tr>
			<td>Dichloromethane (DCM)</td>
			<td>Sigma-Aldrich</td>
			<td>270997</td>
			<td>Solvent</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma-Aldrich</td>
			<td>34860</td>
			<td>Solvent</td>
		</tr>
		<tr>
			<td>trans-4-bromo-&#946;-nitrostyrene</td>
			<td>Sigma-Aldrich</td>
			<td>400017</td>
			<td>Nitro-olefin solid</td>
		</tr>
		<tr>
			<td>trans-3,4-dimethoxy-&#946;-nitrostyrene</td>
			<td>Sigma-Aldrich</td>
			<td>S752215</td>
			<td>Nitro-olefin solid</td>
		</tr>
		<tr>
			<td>trans-2,4-dichloro-&#946;-nitrostyrene</td>
			<td>Sigma-Aldrich</td>
			<td>642169</td>
			<td>Nitro-olefin solid</td>
		</tr>
		<tr>
			<td>trans-&#946;-nitrostyrene</td>
			<td>Sigma-Aldrich</td>
			<td>N26806</td>
			<td>Nitro-olefin solid</td>
		</tr>
		<tr>
			<td>Triethylamine (TEA)</td>
			<td>Sigma-Aldrich</td>
			<td>T0886</td>
			<td>Solvent</td>
		</tr>
		<tr>
			<td>Trimethylsilyl chloride (TMSCl)</td>
			<td>Sigma-Aldrich</td>
			<td>386529</td>
			<td>Reagent; CAUTION - highly volatile; creates HCl gas</td>
		</tr>
		<tr>
			<td>Tetra-n-butylammonium fluoride (TBAF) in Tetrahydrofuran (THF)</td>
			<td>Sigma-Aldrich</td>
			<td>216143</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Tetrahydrofuran (THF)</td>
			<td>Sigma-Aldrich</td>
			<td>401757</td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>1-Bromooctane</td>
			<td>Sigma-Aldrich</td>
			<td>152951</td>
			<td>Alkyl-halide</td>
		</tr>
		<tr>
			<td>Iodomethane</td>
			<td>Sigma-Aldrich</td>
			<td>289566</td>
			<td>Alkyl-halide</td>
		</tr>
		<tr>
			<td>Allylbromide</td>
			<td>Sigma-Aldrich</td>
			<td>337528</td>
			<td>Alkyl-halide</td>
		</tr>
		<tr>
			<td>Benzylbromide</td>
			<td>Sigma-Aldrich</td>
			<td>B17905</td>
			<td>Alkyl-halide</td>
		</tr>
		<tr>
			<td>Glassware/Instrumentation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>25 mL solid-phase reaction vessel</td>
			<td>Chemglass</td>
			<td>CG-1861-02</td>
			<td>Glassware with filter</td>
		</tr>
		<tr>
			<td>Thermo Scientific Nicole iS5</td>
			<td>Thermo Scientific</td>
			<td>IQLAADGAAGFAHDMAZA</td>
			<td>Instrument</td>
		</tr>
		<tr>
			<td>AVANCE III NMR Spectrometer</td>
			<td>Bruker</td>
			<td>N/A</td>
			<td>Instrument; 300 MHz; Solvents: CDCl3 and CD3OH</td>
		</tr>
		<tr>
			<td>Wrist-Action Shaker Model 75</td>
			<td>Burrell Scientific</td>
			<td>757950819</td>
			<td>Instrument</td>
		</tr>
	</tbody>
</table>

solid-phase synthesis of [4.4] spirocyclic oximes

Spirocyclic heterocycles için uygun bir sentetik yol de sonra molekülü'nın potansiyel kullanım nedeniyle biyolojik sistemlerde aranır. Katı faz sentez yoluyla, Michael (REM) bağlayıcı stratejileri ve 1,3-dipolar cycloaddition, yapısal olarak benzer heterocycles, olan ve olmayan bir spirocyclic Merkezi Kütüphanesi yeniden inşa edilecek. Katı-destek sentezi başlıca avantajları şunlardır: yüksek verim; kaynaklanan reaktifler büyük bir fazlalığı kullanarak tamamlanması için her tepki adım ilk, yönlendirilmesi ileri, piyasada bulunan başlangıç malzeme ve reaktifler kullanımı maliyetleri düşük tutmak; son olarak, reaksiyon adımları üzerinden basit filtrasyon arındırmak kolaydır. REM bağlayıcı strateji kendi geri dönüşüm ve traceless doğa nedeniyle çekici olduğunu. Bir reaksiyon düzeni tamamlandığında, bağlayıcı birden çok kez yeniden kullanılabilir. Tipik bir katı fazlı sentezinde ürünün bir parçası veya istenmeyen kanıtlayabilirim bütün bağlayıcı içeriyor. REM bağlayıcı "traceless" ve ek ürün ve polimer arasında ayırt edilemez noktasıdır. İntramolecular 1,3-dipolar cycloaddition yüksek diastereoselectivity iyi belgelenmiştir. Sağlam destek insolubility tarafından sınırlı, reaksiyon ilerleme sadece değişiklik fonksiyonel gruplar ile (varsa) izlenebilir kızılötesi (IR) spektroskopisi ile . Böylece, ara ürün yapısal tanımlaması konvansiyonel nükleer manyetik rezonans (NMR) spektroskopisi ile karakterize olamaz. Bu yöntem diğer sınırlamalar polimer/bağlayıcı uyumlulukları istenilen kimyasal reaksiyon şeması kök. Burada biz bu basit değişiklikler ile yüksek-den geçerek teknikleri ile otomatik olarak spirocyclic heterocycles uygun üretimi için izin veren bir protokol raporu.

Yukarıdaki yordamda belirtildiği gibi sentetik rota için (bkz. Şekil 1) spirocyclic oximes furfurylamine 1, 2göze REM bağlayıcı, bileşik Michael eklenmesi ile başlar. Bir sonraki Michael toplama ve çeşitli β-nitrostyrene türevleri verim trisiklik bileşik 3, bir N- silyloxy isoxazolidine dört benzersiz stereogenic merkezleri ile kullanarak destek 2 1,3-dipolar cycloadd...

Watch this Scientific Journal Video about Solid-phase Synthesis of [4.4] Spirocyclic Oximes at JoVE.com

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

Burada spirocyclic heterocycles sentezi için verimli bir yöntem göstermek için bir iletişim kuralı mevcut. Beş adımlık süreç katı fazlı sentezi ve Michael bağlayıcı stratejileri yeniden kullanır. Genellikle sentezlemek zor, biz spirocyclic moleküller diğer modern yaklaşımlar aksi ulaşılmaz sentezi için özelleştirilebilir bir yöntem mevcut.

Katı faz [4.4] Spirocyclic Oximes sentezi

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...

Bu katı faz organik sentetik teknik bir kombinatoryal kütüphane yapımında uygulamalar bulabilirsiniz, het spirosiklik heterocycles sentezi ise, hangi biyoassays kullanarak anti-kanser faaliyetleri için test edilebilir. Bu yöntem spirosiklik bileşiklerin sentezi için kullanılabilir rağmen, aynı zamanda diğer küçük moleküllere uygulanabilir, gibi isoksazolines ve isoksazoller. Senteze başlamak için, 25 milileter katı faz reaksiyon kabına bir gram REM reçine, 20 militilformamid milileter ve 2,4 mililitre furfurylamin ekleyin.Kap kabı ve furfurylamine reçine yüklemek için oda sıcaklığında bir shaker üzerinde 24 saat boyunca ajite. Sonra furfurylamine rulman reçine drenaj ve yıkamak için DMF beş mililitre yaklaşık üç dakika boyunca ajite. Bundan sonra, reçine bünyesine bçalışmak için beş mililitre diklorometan ve rekarne yiyerek beş mililitre metanol arasında değişen reçiyiyi dört kez yıkayın.Sonra iyice genellikle yaklaşık 30 dakika sürer basınçlı hava ile resenin kuru. Sonra, iyi havalandırılmış bir duman kaputunda, 1.48 mililitre trietilamin, 10 mililitre susuz toluen ve 637 gram beta nitrostiren ekleyin. Reaksiyon karışımına bir mililitre trimethylsilyl klorür ekleyin.Ve karışım hidroklorür gazı salınımı bitene kadar damarı açık bırakın. Sonra kap kap ve isoksazol ara oluşturmak için oda sıcaklığında 48 saat boyunca karışımı ajite. Bundan sonra, reaksiyon söndürmek için metanol beş mililitre ekleyin.Karışımı üç dakika çalkalayın ve iki dakika bekletin. Sonra reçin drenaj ve dört kez yıkayın, DCM beş mililitre arasında dönüşümlü, ve metanol beş mililitre. Yıkanmış resenin basınçlı hava ile iyice kurutuluz.Sonra, kuru rezorne bir mililitre susuz tetrahidrofuran ekleyin. Daha sonra THF tetra-n-butylammonium flouride bir azı kaşığı çözelti1.24 mililitre ekleyin ve isoksazol halkasını açmak için oda sıcaklığında 12 saat boyunca karışımı ajite. Daha sonra, reçin süzün ve THF beş mililitre ile yıkayın, dcm beş mililitre ve metanol beş mililitre arasında değişen dört yıkar izledi.Resenini basınçlı hava ile iyice kurutun. Sonra, rezorin dmf beş mililitre ekleyin, bir-bromooctane bir mililitre takip. Kuaternary amin oluşturmak için oda sıcaklığında 24 saat boyunca karışımı çalkalayın.Sonra reçin drenaj ve DMF beş mililitre ile yıkayın. Reçiyiyi dcm ve metanol arasında dönüşümlü olarak dört kez daha yıkayın ve basınçlı hava ile kurulayın. Sonra, kuru reçine dcm üç mililitre ekleyin, ÇAY 1.5 mililitre takip.Polimer desteğinden spirosiklik oksim cleave için 24 saat boyunca karışımı çalkalayın. Sonra, bir şişe veya şişe ham ürün toplamak. Reçiyiyi dcm ve metanol arasında dönüşümlü olarak dört kez yıkayın ve ürün şişesinde yıkama ları toplayın.Döner buharlaştırıcı üzerindeki ürün karışımından uçucu maddeleri çıkarın. Daha sonra, kaynayan metanol 5 mililitre ile ham ürün triturate ve dikkatle sıvı çıkarın. Reçiyiyi beş mililitrelik DCM porsiyonlarıyla iki kez yıkayın ve sonraki deneylerde yeniden kullanmak üzere basınçlı hava ile kurulayın.Çeşitli ikamelere sahip spirosiklik oksimler mükemmel stereoseçicilik ile sentezlendi. Toplam verim, her sentetik adım için ortalama %80 ila %88 verim gösterir. Isoksazol halkası açılışından kadar olan reaksiyon ilerlemesi IR spektroskopisi ile izlenebilir.Genellikle, bu yönteme yeni bireyler uygun polimer destek bağlayıcı seçimi ile mücadele. Bağlayıcının sentez sırasında tüm reaksiyon koşullarına karşı sağlam olması esastır. Bu yordamı çalışırken, bir sonraki reaksiyon adımından önce reçiyiyi yıkamayı ve kurutmayı unutmayın.Bir önceki adımdan kalan reaktifler genel sentezi zorlaştıracak ve spirosiklik ürünün verimini ve saflığını etkileyecektir.

solid-phase-synthesis-of-44-spirocyclic-oximes

Research

JoVE Journal

Chemistry

Synthesis of Immunotargeted Magneto-plasmonic Nanoclusters

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications including contrast enhancement in novel magnetomotive imaging modalities, simultaneous capture&#160;and detection of circulating tumor cells (CTCs),&#160;and multimodal molecular imaging combined with photothermal therapy of cancer cells. These applications have stimulated significant interest in development of protocols for synthesis of magneto-plasmonic nanoparticles with optical absorbance in the near-infrared (NIR) region and a strong magnetic moment. Here, we present a novel protocol for synthesis of such hybrid nanoparticles that is based on an oil-in-water microemulsion method. The unique feature of the protocol described herein is synthesis of magneto-plasmonic nanoparticles of various sizes from primary blocks which also have magneto-plasmonic characteristics. This approach yields nanoparticles with a high density of magnetic and plasmonic functionalities which are uniformly distributed throughout the nanoparticle volume. The hybrid nanoparticles can be easily functionalized by attaching antibodies through the Fc moiety leaving the Fab portion that is responsible for antigen binding available for targeting.

Here, we describe a protocol for synthesis of magneto-plasmonic nanoparticles with a strong magnetic moment and a strong near-infrared (NIR) absorbance. The protocol also includes antibody conjugation to the nanoparticles through the Fc moiety for various biomedical applications which require molecular specific targeting.

Immunotargeted sentezi Magneto-plasmonik nanoklastırlar

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications ...

Kimya

Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology

Early detection is a key to successful treatment of most diseases, and is particularly imperative for the diagnosis and treatment of many types of cancer. The most common techniques utilized are imaging modalities such as Magnetic Resonance Imaging (MRI), Positron Emission Topography (PET), and Computed Topography (CT) and are optimal for understanding the physical structure of the disease but can only be performed once every four to six weeks due to the use of imaging agents and overall cost. With this in mind, the development of &#8220;point of care&#8221; techniques, such as biosensors, which evaluate the stage of disease and/or efficacy of treatment in the clinician&#8217;s office and do so in a timely manner, would revolutionize treatment protocols.1 As a means to exploring ferrocene based biosensors for the detection of biologically relevant molecules2, methods were developed to produce ferrocene-biotin bio-conjugates described herein. This report will focus on a biotin-ferrocene-cysteine system that can be immobilized on a gold surface.

The synthesis of asymmetric species of ferrocene is challenging using solution techniques. This report focuses on the methods carried out to produce a ferrocene-biotin bioconjugate using facile and clean reactions accomplished via solid-phase synthesis. Incorporation of a thiolate moiety is shown to impart the ability for immobilization on gold surfaces.

Katı Faz Reçine-tabanlı Metodoloji aracılığıyla Asimetrik Ferrosen Türetilmiş Bio-konjuge Sistemleri Sentetik Metodoloji

Early detection is a key to successful treatment of most diseases, and is particularly imperative for the diagnosis and treatment of many types of cancer. ...

Synthesis of Indoxyl-glycosides for Detection of Glycosidase Activities

Indoxyl glycosides proved to be valuable and versatile tools for monitoring glycosidase activities. Indoxyls are released by enzymatic hydrolysis and are rapidly oxidized, for example by atmospheric oxygen, to indigo type dyes. This reaction enables fast and easy screening in vivo without isolation or purification of enzymes, as well as rapid tests on agar plates or in solution (e.g., blue-white screening, micro-wells) and is used in biochemistry, histochemistry, bacteriology and molecular biology. Unfortunately the synthesis of such substrates proved to be difficult, due to various side reactions and the low reactivity of the indoxyl hydroxyl function. Especially for glucose type structures low yields were observed. Our novel approach employs indoxylic acid ester as key intermediates. Indoxylic acid esters with varied substitution patterns were prepared on scalable pathways. Phase transfer glycosylations with those acceptors and peracetylated glycosyl halides can be performed under common conditions in high yields. Ester cleavage and subsequent mild silver mediated glycosylation yields the peracetylated indoxyl glycosides in high yields. Finally deprotection is performed according to Zempl&#233;n.

Indoxyl glycosides are well-established and widely used tools for enzyme screening and enzyme activity monitoring. Especially for glucose type structures previous syntheses proved to be challenging and low yielding. Our novel approach employs indoxylic acid esters as precious intermediates to yield a considerable number of indoxyl glycosides in good yields.

Glikosidaz Faaliyetlerinin Belirlenmesi için indoksil-glikozitler sentezi

Indoxyl glycosides proved to be valuable and versatile tools for monitoring glycosidase activities. Indoxyls are released by enzymatic hydrolysis and are ...

Hydroquinone Based Synthesis of Gold Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag+) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

This paper describes a protocol for the synthesis of gold nanorods, based on the use of hydroquinone as reducing agent, plus the different mechanisms for controlling their size and aspect ratio.

Altın nanorods hidrokinon Esaslı Sentezi

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the ...

Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees

A two-step chemical vapor deposition procedure is here employed to prepare tree-like hierarchical ZnO/CdSSe hetero-nanostructures. The structures are composed of CdSSe branches grown on ZnO nanowires that are vertically aligned on a transparent sapphire substrate. The morphology was measured via scanning electron microscopy. The crystal structure was determined by X-ray powder diffraction analysis. Both the ZnO stem and CdSSe branches have a predominantly wurtzite crystal structure. The mole ratio of S and Se in the CdSSe branches was measured by energy dispersive X-ray spectroscopy. The CdSSe branches result in strong visible light absorption. Photoluminescence (PL) spectroscopy showed that the stem and branches form a type-II heterojunction. PL lifetime measurements showed a decrease in the lifetime of emission from the trees when compared to emission from individual ZnO stems or CdSSe branches and indicate fast charge transfer between CdSSe and ZnO. The vertically aligned ZnO stems provide a direct electron transport pathway to the substrate and allow for efficient charge separation after photoexcitation by visible light. The combination of the abovementioned properties makes ZnO/CdSSe nanotrees promising candidates for applications in solar cells, photocatalysis, and opto-electronic devices.

Here, we prepare and characterize novel tree-like hierarchical ZnO/CdSSe nanostructures, where CdSSe branches are grown on vertically aligned ZnO nanowires. The resulting nanotrees are a potential material for solar energy conversion and other opto-electronic devices.

Hiyerarşik ZnO / CdSSe Heteroyapı Nanotrees sentezi

A two-step chemical vapor deposition procedure is here employed to prepare tree-like hierarchical ZnO/CdSSe hetero-nanostructures. The structures are ...

Integration of Miniaturized Solid Phase Extraction and LC-MS/MS Detection of 3-Nitrotyrosine in Human Urine for Clinical Applications

Free 3-nitrotyrosine (3-NT) has been extensively used as a possible biomarker for oxidative stress. Increased levels of 3-NT have been reported in a wide variety of pathological conditions. However, existing methods lack the sufficient sensitivity and/or specificity necessary to measure the low endogenous level of 3-NT reliably and are too cumbersome for clinical applications. Hence, analytical improvement is urgently needed to accurately quantify the levels of 3-NT and verify the role of 3-NT in pathological conditions. This protocol presents the development of a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) detection combined with a miniaturized solid phase extraction (SPE) for the rapid and accurate measurement of 3-NT in human urine as a non-invasive biomarker for oxidative stress. SPE using a 96-well plate markedly simplified the process by combining sample cleanup and analyte enrichment without tedious derivatization and evaporation steps, reducing solvent consumption, waste disposal, risk of contamination and overall processing time. The employment of 25 mM ammonium acetate (NH4OAc) at pH 9 as the SPE elution solution substantially enhanced the selectivity. Mass spectrometry signal response was improved through adjustment of the multiple reaction monitoring (MRM) transitions. Use of 0.01% HCOOH as additive on a pentafluorophenyl (PFP) column (150 mm x 2.1 mm, 3 &#181;m) improved signal response another 2.5-fold and shortened the overall run time to 7 min. A lower limit of quantitation (LLOQ) of 10 pg/mL (0.044 nM) was achieved, representing a significant sensitivity improvement over the reported assays. This simplified, rapid, selective and sensitive method allows two plates of urine samples (n = 192) to be processed in a 24 h time-period. Considering the markedly improved analytical performance, and non-invasive and inexpensive urine sampling, the proposed assay is beneficial for pre-clinical and clinical studies.

A selective and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method coupled with an efficient solid phase extraction on a mixed-mode cation-exchange (MCX) 96-well microplate was developed for the measurement of free 3-nitrotyrosine (3-NT) in human urine with high throughput, which is suitable for clinical applications.

Klinik Uygulamalar İçin İnsan İdrarında 3-Nitrotirosinin Minyatür Katı Faz Çıkarma ve LC-MS / MS Algılamasının Entegrasyonu

Free 3-nitrotyrosine (3-NT) has been extensively used as a possible biomarker for oxidative stress. Increased levels of 3-NT have been reported in a wide ...

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular methodology for applications in various fields and for different research purposes. The procedure described herein focuses on the synthesis, purification, and characterization of dodecamers of RNA 5&#39;-[CUA CGG AAU CAU]-3&#39; containing zero, one, or two modifications located at the C2&#39;-O-position. The probes are based on 2-thiophenylmethyl groups, incorporated into RNA nucleotides via standard organic synthesis and introduced into the corresponding oligonucleotides via their respective phosphoramidites. This report makes use of phosphoramidite chemistry via the four canonical nucleobases (Uridine (U), Cytosine (C), Guanosine (G), Adenosine (A)), as well as 2-thiophenylmethyl functionalized nucleotides modified at the 2&#39;-O-position; however, the methodology is amenable for a large variety of modifications that have been developed over the years. The oligonucleotides were synthesized on a controlled-pore glass (CPG) support followed by cleavage from the resin and deprotection under standard conditions, i.e., a mixture of ammonia and methylamine (AMA) followed by hydrogen fluoride/triethylamine/N-methylpyrrolidinone. The corresponding oligonucleotides were purified via polyacrylamide electrophoresis (20% denaturing) followed by elution, desalting, and isolation via reversed-phase chromatography (Sep-pak, C18-column). Quantification and structural parameters were assessed via ultraviolet-visible (UV-vis) and circular dichroism (CD) photometric analysis, respectively. This report aims to serve as a resource and guide for beginner and expert researchers interested in embarking in this field. It is expected to serve as a work-in-progress as new technologies and methodologies are developed. The description of the methodologies and techniques within this document correspond to a DNA/RNA synthesizer (refurbished and purchased in 2013) that uses phosphoramidite chemistry.

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2&#039;-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

This article provides a detailed procedure on the solid-phase synthesis, purification, and characterization of dodecamers of RNA modified at the C2&#39;-O-position. UV-vis and circular dichroism photometric analyses are used to quantify and characterize structural aspects, i.e., single-strands or double-strands.

Bir 2&#39;-amino asit içeren RNA Oligomerlerinin Katı Faz Sentezi Protokolü<em&gt; Ç</em&gt; Tiyofenilmetil Değiştirme ve Sirküler Dikroizm ile Karakterizasyonlar

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a challenge, as it requires asymmetric growth of symmetric crystals. Here, we report a distinctive synthesis of substrate-bound Au nanowires. This template-free synthesis employs thiolated ligands and substrate adsorption to achieve the continuous asymmetric deposition of Au in solution at ambient conditions. The thiolated ligand prevented the Au deposition on the exposed surface of the seeds, so the Au deposition only occurs at the interface between the Au seeds and the substrate. The side of the newly deposited Au nanowires is immediately covered with the thiolated ligand, while the bottom facing the substrate remains ligand-free and active for the next round of Au deposition. We further demonstrate that this Au nanowire growth can be induced on various substrates, and different thiolated ligands can be used to regulate the surface chemistry of the nanowires. The diameter of the nanowires can also be controlled with mixed ligands, in which another &#34;bad&#34; ligand could turn on the lateral growth. With the understanding of the mechanism, Au nanowire-based nanostructures can be designed and synthesized.

We report a solution-based method to synthesize substrate-bound Au nanowires. By tuning the molecular ligands used during the synthesis, the Au nanowires can be grown from various substrates with different surface properties. Au nanowire-based nanostructures can also be synthesized by adjusting the reaction parameters.

Substrat bağlı Au Nanowires bir aktif yüzey büyüme mekanizması yoluyla sentezi

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

Solid Phase 11C-Methylation, Purification and Formulation for the Production of PET Tracers

Routine production of radiotracers used in positron emission tomography (PET) mostly relies on wet chemistry where the radioactive synthon reacts with a non-radioactive precursor in solution. This approach necessitates purification of the tracer by high performance liquid chromatography (HPLC) followed by reformulation in a biocompatible solvent for human administration. We recently developed a novel 11C-methylation approach for the highly efficient synthesis of carbon-11 labeled PET radiopharmaceuticals, taking advantage of solid phase cartridges as disposable &#34;3-in-1&#34; units for the synthesis, purification and reformulation of the tracers. This approach obviates the use of preparative HPLC and reduces the losses of the tracer in transfer lines and due to radioactive decay. Furthermore, the cartridge-based technique improves synthesis reliability, simplifies the automation process and facilitates compliance with the Good Manufacturing Practice (GMP) requirements. Here, we demonstrate this technique on the example of production of a PET tracer Pittsburgh compound B ([11C]PiB), a gold standard in vivo imaging agent for amyloid plaques in the human brains.

Solid Phase 11C-Methylation, Purification and Formulation for the Production of PET Tracers

We report an efficient carbon-11 radiolabeling technique to produce clinically relevant tracers for Positron Emission Tomography (PET) using solid phase extraction cartridges. 11C-methylating agent is passed through a cartridge preloaded with precursor and successive elution with aqueous ethanol provides chemically and radiochemically pure PET tracers in high radiochemical yields.

Pet İzleyicilerin Üretimi için Katı Faz 11C-Metilasyon, Arıtma ve Formülasyon

Routine production of radiotracers used in positron emission tomography (PET) mostly relies on wet chemistry where the radioactive synthon reacts with a ...

Gas Chromatography-Mass Spectrometry Paired with Total Vaporization Solid-Phase Microextraction as a Forensic Tool

Gas Chromatography &#8211; Mass Spectrometry (GC-MS) is a frequently used technique for the analysis of numerous analytes of forensic interest, including controlled substances, ignitable liquids, and explosives. GC-MS can be coupled with Solid-Phase Microextraction (SPME), in which a fiber with a sorptive coating is placed into the headspace above a sample or immersed in a liquid sample. Analytes are sorbed onto the fiber which is then placed inside the heated GC inlet for desorption. Total Vaporization Solid-Phase Microextraction (TV-SPME) utilizes the same technique as immersion SPME but immerses the fiber into a completely vaporized sample extract. This complete vaporization results in a partition between only the vapor phase and the SPME fiber without interference from a liquid phase or any insoluble materials. Depending upon the boiling point of the solvent used, TV-SPME allows for large sample volumes (e.g., up to hundreds of microliters). On-fiber derivatization may also be performed using TV-SPME. TV-SPME has been used to analyze drugs and their metabolites in hair, urine, and saliva. This simple technique has also been applied to street drugs, lipids, fuel samples, post-blast explosive residues, and pollutants in water. This paper highlights the use of TV-SPME to identify illegal adulterants in very small samples (microliter quantities) of alcoholic beverages. Both gamma-hydroxybutyrate (GHB) and gamma-butyrolactone (GBL) were identified at levels that would be found in spiked drinks. Derivatization by a trimethylsilyl agent allowed for conversion of the aqueous matrix and GHB into their TMS derivatives. Overall, TV-SPME is quick, easy, and requires no sample preparation aside from placing the sample into a headspace vial.

Total Vaporization Solid Phase Microextraction (TV-SPME) completely vaporizes a liquid sample whilst analytes are sorbed onto a SPME fiber. This allows for partitioning of the analyte between only the solvent vapor and the SPME fiber coating.

Gaz Kromatografisi-Kütle Spektrometresi, Adli Bir Araç Olarak Toplam Buharlaşma Katı Fazlı Mikroextraction ile Eşleştirilmiştir

Gas Chromatography &#8211; Mass Spectrometry (GC-MS) is a frequently used technique for the analysis of numerous analytes of forensic interest, including ...