新鄂西香茶菜素的X射线结构分析

新鄂西香茶菜素为首次从抗癌中草药鄂西香茶菜[Rabdosia henryi (Hemsl) Hara]的叶子中分离得到的二萜化合物。前人曾从毛叶香茶菜[R. japonica (Burm. f)Hara]中分离出该化合物并依据光谱数据推测其结构(右图)。但其结晶学研究尚未见报道。为研究其立体结构及分子在晶体中的排布方式,我们对该化合物的晶体进行了X射线结构分析。     

溪黄草总二萜提取工艺及抑制亚硝化反应的研究

唇形科香茶菜属植物溪黄草(Rabdosia serra(Maxim·)Hara)具有清热祛湿、凉血散瘀、抗肿瘤、抗菌、消炎及对肝脏的保护作用[1,2]。据文献报道,溪黄草中的对映-贝壳杉烷型二萜化合物,是其具有抗癌作用的主要功效成分[3-5]。其结构与冬凌草甲素极为相似,在同一波长处具有相似的紫     

大萼香茶菜挥发油化学成分的气相色谱/质谱法分析

采用常规水蒸气蒸馏法提取出大萼香香茶菜挥发油，经气相色谱－质谱联机分析，分离出116个峰，确认了其中60种成分，所鉴定的组分占总峰面积的75．77％。     

新香茶菜素的结构

从河南大别山地区产显脉叶香茶菜[Rabdosia nervosa(Hemsl.)C.Y.Wu et H.W.Li]叶的乙醚提取物中分离到三个二萜化合物,其中 odonicin 和显脉香茶菜素(nervosin)已报道,本文报道另一个新化合物,命名为新香茶菜素(neorabdosin,1)的结构研究.1为无色针状结晶,有微弱芳香气味,熔点230～232℃,[α]_D~(13)-175.5°(c 0.86,吡啶).经元素分析和质谱测定,其分子式为 C_(24)H_(30)O_7,M_r=430.48.IR:1735,1220(乙酰基),1720(六     

大叶香茶菜辛素的晶体结构和分子结构

程培元和许美娟等人,从抗癌中草药大叶香茶菜(Rabdosia Macrophylla)中分离得一种新的、饱和的贝壳杉型二萜类化合物:C_(24)H_(36)O_9,定名为大叶香茶菜辛素(Rabdophyllin-A,以下简称为大叶辛素)。从化学和光谱学数据可得出如下的结构式。     

香茶菜属植物二萜和五味子降三萜合成进展

香茶菜属植物和五味子科植物是两大重要的药用植物类群,而香茶菜属植物二萜和五味子降三萜的研究则是近年来天然产物研究领域具有代表性研究成果之一.目前,从香茶菜属植物中已发现1200多个二萜类化合物,涉及11种结构类型;而从五味子科植物中已发现200多个五味子降三萜(schinortriterpenoids,SNTs),包括二十余种不同骨架类型.由于其多样的结构类型和显著的生物活性引起了国内外合成化学家的广泛关注.对近十年来香茶菜属植物二萜和五味子降三萜的合成进行综述.     

乌拉尔甘草种子油挥发性成分的超临界二氧化碳/气相色谱-质谱分析

采用超临界二氧化碳萃取法(SFE—CO2)提取的乌拉尔甘草种子油,用气相色谱-质谱(GC—MS)联用技术对其挥发性成分进行了分析,首次分离得到52个峰,确定了其中的16种化合物;采用峰面积归一化法计算各成分相对百分含量,所鉴定成分占总馏出峰面积的80．85％。主要成分邻苯二甲酸二丁酯和β-谷甾醇乙酸酯具有较多的生理活性,为进一步开发甘草种子油新药研究提供了依据。     

高氧化态对映-贝壳杉烯二萜类天然产物的全合成

<正>J.Am.Chem.Soc.2017,139,6098~6101唇形科香茶菜属植物是我国民间广泛使用的中草药,迄今为止已从中分离得到1000余个对映-贝壳杉烯二萜类化合物(ent-kaurenoids).这类天然产物大多具有较强的抗菌活性、抗疟活性、抗肿瘤活性和抗病毒活性等.同时,由     

超临界CO_2萃取姜油的组成研究

用超临界ＣＯ＿２萃取法从冷冻干燥的姜中萃取出姜油。通过薄层色谱、柱色谱、气相色谱以及色谱。质谱联用等手段进行组成剖析,并与水汽蒸馏法获得的姜油进行一些比较。结果表明超临界ＣＯ＿２萃取法不仅能获得姜中的挥发油组分,而且能同时获得各种姜辣素成分。此法萃取的姜油目前已鉴定出的组分有９７个,占色谱峰总面积的９３％左右。     

用NMR研究和确定川藏香茶菜中一种新成分化学结构

本文报告了用NMR方法并结合其它结构信息,研究并首次确定了川藏香茶菜[Isodon pha-ricus(prian)murata]中一种新的贝壳杉烯型二萜,并命名为川藏香茶菜甲素(Isodopharicin A)。     

Preparation of New Substituted Bis(benzoyl) Peroxides under Aqueous Conditions in the Presence of Stearyltrimethylammonium Chloride

Summary. A series of new substituted bis(benzoyl) peroxides has been synthesised from their corresponding acid chlorides in high yield. The reactions were carried out in aqueous sodium peroxide solution and butanone in the presence of 0.5% stearyltrimethylammonium chloride (STAC) at a temperature below 15°C. STAC improved the purity, and the fast addition improved the yield of the peroxides. Mass spectral analysis of substituted bis(benzoyl) peroxides using EI has been carried out for accurate mass determinations.Present address: Boron Molecular Ltd. PO Box 756, Noble Park, VIC, Australia 3174Author to receive any questions about mass spectral analysis     

四氯合锌酸十四烷铵-四氯合锌酸十六烷铵二元体系相图

合成了四氯合锌酸十四烷铵(C4H29NH3)2ZnCl4(简记为C14ZnCl)和四氯合锌酸十六烷铵(C16H33NH3)2ZnCl4(简记为C16ZnC1),并配制了一系列不同组成的C14ZnCl-C16ZnCl二元体系,通过DSC测试,变温红外光谱法及X-ray粉末衍射法来绘制该二元体系相图。该相图是生成稳定中问化合物的固相部分互溶体系相图。     

A New Chiral Synthesis of Naturally Occurring (-)-(S)-4-Hydroxy-2-pyrrolidinone

4-Hydroxy-2-pyrrolidinoneIisanattractivesimplemolecule.First,ithasservedasakeyintermediateinthesynthesis'ofoxiracetam,adrugusefulforimprovinglearningandmemory.Second,IcanbeeasilytransformedintoantiepilepticandhypotensivedrugGABOB',andhypolipidemicagentcarnitine'.Third,(-)-4-hydroxy-2-pyrro-lidinoneIhasbeenisolated'fromthetoadstollAmanitamuscaria.Itsabsoluteconfigurationhasbeenerroneouslyassigned'as(R).ThefirstchiralsynthesisofthiscompoundhasbeenreportedbyPifferi#.However,notuntil1984didi…     

Reductive Cleavage of S-S Bond by Sm/NiCl_2 or Sm/NiCl_2·6H_2O System: A New Method for the Preparation of Thiolesters

Theroleofthiolestersasacylatingagentsinbiochemicalprocessesandtheirhighreactivitywithvariousnucleophiles,hasmadethemanattractivesyntheticintermediateinorganicsynthesis'-'.Manynewmethodshavebeendevelopedforthepreparationofthiolestersinrecentyears'-",forexample,thereactionbetweensodiumthiobenzoateandarenediazoniumtetrafluoroborates',tTedrientofnitrosoamidesornitroamideswithmercaptansinthepresenceofsodiumhydride',thecobaltcarbonylcatalyzedcarbonylationofmercaptans'andthecobaltchloridecatalyzedcou…     

Phosphorus (III) - and Phosphorus (IV)-Substituted Alkoxyacetylenes as New Synthons in Phosphororganic Synthesis

Abstract

The diheterosubstituted acetylenes of EC=COR type, where E is Si, Ge, Sn, B, possessing an increased react-ivity both in reactions with electrophilic reagents and fragmentation processes, are extensively investigated in the Moscow University. At the same time phosphorylated alkoxyacetylenes have gained less attention. The main purpose of this work was the synthesis of previously unknown phosphorus (III)-substituted alkoxyacetylenes (I), investigation of their stability, properties and applications in phosphororganic syntheses.     

A simulation of thermal characteristic parameters with an inverse “S” type curve

A synthetical equation is proposed to characterize the essential features of the inverse “S” type curve on the basis of summing-up simulation approach of “S” type curve. The two physical variables in the model obtained are discussed and the detailed method used to determine the parameters is given. The model is then presented to describe the crystallization of poly(caryleher ether ketone) (PEEK) and thermal decomposition of poly(amide-imide) (PAI) respectively. It is found that some thermal characteristic parameters can be well estimated from the model simu-lated in computer.     

蔬毛吴茱萸果实中新化合物吴茱萸塔宁的分离及结构表征

从传统中药蔬毛吴茱萸的干燥未成熟果实中分离得到一个稀有高氧化状态、新的柠檬苦素类化合物吴茱萸塔宁(evolimorutanin),同时还分离得到了已知结构的化合物柠檬苦素(limonin)。根据IR、MS、1DNMR(1HNMR,13C NMR,DEPT)和2D NMR(1H-1HCOSY,HSQC,HMBC)谱学数据确定了它们的结构,两者均归属为降三萜类化合物,A,A′,B,C,D五个环的取代和立体构型完全相同,只有E环氧化状态不同。此外,还分析了从柠檬苦素转化为吴茱萸塔宁的可能过程。     

Chemoselective oxidation and deprotection of para-methoxybenzylic position with (diacetoxyiodo)benzene in acetic-trifluoroacetic acid

(Diacetoxyiodo)benzene in the presence of acetic–trifluoroacetic acid in THF has been developed for the chemoselective para-methoxybenzylic CH bond oxidation to provide aryl carbonyl compounds at room temperature. The reaction condition is also applicable for the chemoselective deprotection of para-methoxybenzyl (PMB) ether in the presence of benzyl ether.     

新有机试剂4-(2-苯并噻唑偶氮)焦棓酚的合成、性能和分析应用

本文以2-氨基苯并噻唑为原料,经重氮化后与焦棓酚偶联合成了4-(2-苯并噻唑偶氮)焦棓酚,用乙醇重结晶精制。并用元素分析、波谱等鉴定了结构。测定了其离解常数和质子化常数。研究了该试剂的一般性质、多配位显色反应,发现其与Mo(Ⅵ)、W(Ⅵ)、Ti(Ⅳ)等的显色反应在CTMAB和CPB等阳离子表面活性剂存在下有高的灵敏度。     

A practical stereoselective synthesis of (S)-( - )-ofloxacin

A very efficient and practical procedure for preparation of ( S)-( - )-ofloxacin has been developed (10 steps, overall yield ≥ 45 % ) . The key step of this approach is the regioselective nucleophilic substitution of 2-position fluorine atom of 2,3,4-tirfluoronitrobenzene by (S)-glycerol acetonide.