β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯/冰片酯合成研究

以3,4-二羟基苯甲醛为起始原料, 经苄基保护、Darzens环氧化、Lewis酸开环、NaBH4还原、催化加氢脱保护得到β-(3,4-二羟基苯基)-α-羟基丙酸异丙酯和β-(3,4-二羟基苯基)-α-羟基丙酸冰片酯, 所得化合物的结构通过1H NMR、13C NMR, IR, MS证实. 该方法操作简单、毒性低、产物易于纯化.     

11α，17-二羟基-及11β，17-二羟基-雄甾-1，4-二烯-3-酮-17腈羟基保护的研究

11α，17-二羟基-及11β，17-二羟基-雄甾-1，4-二烯-3-酮-17腈以乙烯基正 丁醚进行保护，得到双羟基和11-及17-单羟基保护产物，对因保护基引入手性碳而 产生的双羟基保护产物的立体异构体进行了分离纯化和波谱鉴定；单羟基保护产物 的薄层层析和分离中均未能观察到立体异构体的性质差异。     

质谱、红外和核磁研究木质素模型物在Co-salen仿酶体系中的降解反应

根据GC-MS、FT-IR和13C-NMR对降解产物与结构变化的分析,可得出紫丁香基木质素模型物在Co-salen仿酶反应体系中的降解机理.质谱、红外光谱和核磁检测结果表明,反应过程中,木质素模型物β-O-4、Cα-Ar、Cα-Cβ连接断裂,苯环开环,同时发生酚羟基醚化和甲氧基脱甲基反应,产生4-羟基-3,5-二甲氧基苯乙酮、4-羟基-3,5-二甲氧基苯甲醛、4-羟基-3,5-二甲氧基苯甲酸、3-羟基-4,5-二甲氧基苯甲酸.     

高效液相色谱-电喷雾质谱联用测定黄芪黄酮苷酶解产物

高效液相色谱-电喷雾质谱(HPLC-ESI-MS)联用分析黄芪中的黄酮类化合物结果表明黄芪黄酮提取物主要包含毛蕊异黄酮-7-O-β-D-葡萄糖苷、芒柄花苷、9, 10 -二甲氧基紫檀烷-3-O-β-D-葡萄糖苷以及2'-羟基-3',4'-二甲氧基异黄烷-7-O-β-D-葡萄糖苷等黄酮苷,黄芪黄酮提取物经过β-葡萄糖苷酶(1 IU/mL)粗酶液酶解后,HPLC-ESI-MS分析酶解生成产物主要为黄酮苷元毛蕊异黄酮、芒柄花素、3-羟基-9,10 -二甲氧基紫檀烷以及7, 2'-二羟基-3',4'-二甲氧基异黄烷.其中前两种主要的黄酮苷酶解率均达90%以上.酶解后所得产物对DPPH自由基清除率是酶解前的1.4倍.因此,通过β-葡萄糖苷酶水解可以有效地将黄芪黄酮转化为相应的黄酮苷元,大大提高黄芪黄酮提取物的抗氧化活性.     

大叶桉化学成分的研究 - 大叶桉酚乙和其它成分的分离和鉴定

从大叶桉叶的乙醇提取物中分离并鉴定出九种已知成分:5-羟基-4',7-二甲氧基6,8-二甲基黄酮,4',5-二羟基-7-甲氧基6,8-二甲基黄酮,3β-羟基-乌索-11-烯-28,13β-内酯,13β-乙酰氧基-乌索-11-烯-28,13β-内酯;3β,28-二羟基-乌索-12-烯,β-谷甾醇,2-甲基5,7-二羟基-苯骈吡喃酮-7β-葡萄糖苷,正卅烷醇和正卅烷酸,另外,分得一种新的酰基间苯三酚类成分,命名为大叶桉酚乙,其结构为2-甲氧基-4,6-二羟基异丁酰基苯,并进行化学合成确证,大叶桉酚乙在管碟法中对金黄色葡萄球菌和枯草杆菌有抑菌作用。     

几种炔二醇在硫酸汞催化下的环化

本文报道几种炔二醇在硫酸汞催化下的环化反应。γ-炔二醇环化产物的羰基位于原炔二醇中叔醇羟基的β位。而凸σ-炔二醇水化产物的羰基则处于α位。     

Q Exactive四极杆-静电场轨道阱高分辨质谱系统对丹皮酚经大鼠肝微粒体体外代谢产物的分析

以丹皮酚和2,4-二羟基苯乙酮为研究对象,采用Q Exactive四极杆-静电场轨道阱高分辨质谱系统,及内置有Ⅰ相和Ⅱ相代谢途径分析的MetWorks代谢物鉴定软件,系统分析丹皮酚经肝微粒体代谢的Ⅰ相代谢及其Ⅰ相代谢产物2,4-二羟基苯乙酮经微粒体代谢的Ⅱ相代谢产物。结果表明,丹皮酚在大鼠肝微粒体中经Ⅰ相代谢后产物主要为4位去甲基化的2,4-二羟基苯乙酮和1位相邻羰基的脱甲基化的2-羟基-4-甲氧基苯甲醛以及5位的羟基化代谢产物2,5-二羟基-4-甲氧基苯乙酮,而2,4-二羟基苯乙酮的Ⅱ相代谢产物主要为4位葡萄糖醛酸化的糖苷化代谢产物2-羟基-4’-O-葡萄糖醛酸苯乙酮。     

几种α-羟基取代烷基膦酸二(β-氯乙基)酯的制备

Abramov等由亚磷酸二酯和羰基化合物在醇钠的催化下合成一系列α-羟基取代烷基膦酸二酯,(RO)_2P(O)CR′R″OH。在其工作中,发现有些亚磷酸二酯不能或不易和较复杂的醛和酮加成,即使发生作用,而产物不能析出或提纯。作者现在试用不同的芳香醛,肉桂醛和环己酮,与亚磷酸二(β-氯乙基)酯作用,在少量的甲醇钠-甲醇的饱和溶液存在下,发生放热加成反应,产生九种新的固体α-羟基取代烷基膦酸二(β-氯乙基)酯。在实验过程中,产物最初多成胶状的半固体,但是经过冰冷及磨擦器壁,终於变成很好的结晶。作者鉴於α-羟基三氯乙基二甲基膦酸酯和α-羟基三氯乙基二乙基膦酸酯以     

6β-溴-l7β-羟基-4-雌烯-3-酮的脱溴化氢重排反应

在△~(4,6)-二烯-3-酮甾体化合物的诸种合成方法中,6β-溴-△~4-烯-3-酮脱溴化氢方法占有重要的地位。我们曾采用此方法合成了17β-羟基-4,6-雌二烯-3-酮(Ⅰ)。由 3-乙氧基-17β-羟基-3,5-雌二烯(Ⅱ)NBS 溴化制备的6β-溴-17β-羟基-4-雌烯-3-酮(Ⅲ),不经分离纯化,直接溶于DMF,在Li_2CO_3-LiBr催化下脱溴化氢生成Ⅰ。实验中发现,除主要生成Ⅰ外,总有一个极性较小的副产物伴随生成。经分离纯化,该化合物的熔点与雌二醇相近,MS和NMR的测定结果与雌二醇结构相符,说明该产物的确为雌二     

7α-羟基甾体衍生物的生物合成研究

最近,7α-羟基-DHEA已经作为在人的脂肪基质细胞的作用下DHEA代谢的主要产物分离出来[1],并且在人的前列腺组织中也发现了3-β甾体的7-羟基化反应.在活体内将标记的5α-雄甾-3β,17β-二醇注射到人体内结果可以在尿内发现7-羟基化代谢物[2].研究表明7-羟基化的甾体可以提高老鼠的免疫能力,也具有抗糖(肾上腺)皮质激素的作用[3].DHEA在用Fusarium sp.进行生物转化时得到的产物是7α-羟基衍生物,在用Rhizopus sp.进行反应时得到的是7α-OH-DHEA,7β-OH-DHEA和3β-羟基-5-雄甾,7,17-二酮的混合物.Culmorum对5-烯类甾体的羟基化反应主要发生在7α位.Morfin等研究了Fusarium moniliform的DHEA诱导7α-羟基化酶对具有重要的药理作用的3-羟基甾体的转化性,DHEA几乎全部被7α-羟基化,而PREG,EPIA和ESTR只是部分地转化成其7α-羟基衍生物,因而也发生了其它未定位置上的羟基化反应以及将C-17或C-20上羰基还原成醇,这种酶不能转化胆甾醇.     

Oleanane‐Type Triterpenoids from Glochidion assamicum

Phytochemical analysis of the extract of the leaves and twigs of Glochidion assamicum led to the isolation of four new oleanane‐type triterpenoids, 21β‐(benzoyloxy)olean‐12‐ene‐3β,16β,23,28‐tetraol ( 1 ), 21β‐(benzoyloxy)olean‐12‐ene‐3β,16β,28‐triol ( 2 ), 21β‐{(E)‐cinnamoyloxy]olean‐12‐ene‐3β,16β,23, 28‐tetraol ( 3 ), and 21β‐[(Z)‐cinnamoyloxy]olean‐12‐ene‐3β,16β,23,28‐tetraol ( 4 ). Their structures were elucidated on the basis of spectroscopic evidence and mass‐spectral data.     

Triterpenoids from the Leaves of Ilex hainanensis

Phytochemical investigation on the leaves of Ilex hainanensis Merr . led to the isolation of four new ursane‐ and oleanane‐based triterpenoids, ilexhainanins A–D ( 1 – 4 ), as well as two known compounds, 2α,3β,19α‐trihydroxyurs‐12‐ene‐23,28‐dioic acid and 2α,3β,19α‐trihydroxyolean‐12‐ene‐23,28‐dioic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence, and by comparison with literature data.     

Structure elucidation and complete NMR spectral assignments of two new oleanane‐type pentacyclic triterpenoid saponins from the husks of Xanthoceras sorbifolia Bunge

Two new saponins were isolated from husks of Xanthoceras sorbifolia Bunge and their structures were elucidated as 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21‐O‐(3,4‐diangeloyl)‐α‐L‐rhamnose‐3β, 16α, 21β, 22α, 28β‐pentahydroxyl‐22‐acetoxy‐olean‐12‐ene(1) and 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21,22‐O‐diangeloyl‐3β,15α,16α,21β,22α,28β‐hexahydroxyl‐olean‐12‐ene(2) on the basis of 1D and 2D NMR (including ¹H, ¹³C‐NMR, ¹H? ¹H COSY, HSQC, HMBC and DEPT), ESI‐MS spectrometry and chemical methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Two New Disulfated Triterpenoids from Zygophyllum fabago

From the aerial parts of Zygophyllum fabago, two new monosodium salts of sulfated derivatives of ursolic acid, along with two known quinovic acid glycosides were isolated. The structures of the new compounds were determined as (3β,4α)‐3,23,30‐trihydroxyurs‐20‐en‐28‐al 3,23‐di(sulfate) sodium salt (1 : 1) ( 1 ) and of (3β,4α)‐3,23,28‐trihydroxyurs‐20‐en‐30‐yl β‐D ‐glucopyranoside 3,23‐di(sulfate) sodium salt (1 : 1) ( 2 ) with the molecular formula C₃₀H₄₇NaO₁₀S₂ and C₃₆H₅₉NaO₁₅S₂, respectively. The structures of the known compounds were 3‐O‐(2‐O‐sulfo‐β‐D ‐quinovopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 3 ) and 3‐O‐(β‐D ‐glucopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 4 ) (quinovic acid=(3β)‐3‐hydroxyurs‐12‐ene‐27,28‐dioic acid). The structures of all these compounds were determined by using 1D‐ and 2D‐NMR spectroscopic techniques.     

Three New ent‐Trachylobane Diterpenoids from Co‐cultures of the Calli of Trewia nudiflora and Fusarium sp. WXE

Five diterpenoids, including three new ent‐trachylobane diterpenoids, i.e., (3α)‐3‐hydroxy‐ent‐trachylobane‐17,19‐dioic acid 19‐methyl ester ( 1 ), ent‐trachylobane‐17,19‐dioic acid 19‐methyl ester ( 2 ), ent‐trachylobane‐17,19‐dioic acid ( 3 ), and two known atisane‐type ones, i.e., (16α)‐16,17‐dihydroxy‐ent‐atisan‐19‐oic acid methyl ester ( 4 ), and 17‐hydroxy‐ent‐atisan‐19‐oic acid methyl ester ( 5 ), were isolated from the co‐culture extract of the calli of Trewia nudiflora and its endophytic fungus Fusarium sp. WXE. Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and HR‐Q‐TOF mass spectrometry. The antitumor and antibacterial properties of the new compounds were evaluated.     

New Polyoxygenated Triterpenoids from Stachyurus himalaicus var. himalaicus

Two new polyoxygenated triterpenoids, stachlic acid A (= (2α,3β)‐2,3,23,29‐tetrahydroxyolean‐12‐en‐28‐oic acid; 1 ) and stachlic acid B (= (2α,3α)‐2,29‐dihydroxy‐3,23‐[(1,1‐dimethylmethylene)dioxy]olean‐12‐ene‐28‐oic acid; 2 ), were isolated from Stachyurus himalaicus var. himalaicus. Their structures were established by means of extensive spectroscopic studies and chemical evidence. The purified product 1 was found to have moderate in vitro cytotoxic activity against human Hela cells.     

Two Novel Olean Triterpenoids from Celastrus hypoleucus

Two new triterpenoids, (3β)‐olean‐12‐ene‐3,23‐diol ( 1 ) and (6α)‐6‐hydroxyolean‐12‐en‐3‐one ( 2 ) were isolated from the MeOH extract of the stalks of Celastrus hypoleucus (Oliv .) Warb ., together with the seven known compounds (3β,22α)‐3,22‐dihydroxyolean‐12‐en‐29‐oic acid, β‐amyrin and β‐amyrin palmitate, wilforlide A, wilforilide B, palmitic acid, and β‐sitosterol. Their structures were elucidated on the basis of spectroscopic data and, in the case of 2 , by X‐ray crystallography. Compound 1 showed moderate cytotoxicity against human cervical squamous carcinoma (Hela) cells.     

Triterpenoids from the Aerial Parts of Kalidium foliatum

Studies on the chemical constituents of the aerial parts of Kalidium foliatum led to the isolation of three new olean‐12‐ene‐23,28‐dioic acids in their either partly or fully esterified forms (Me or glucosyl (Glc) esters), which were named kalidiumoside A ( 1 ), kalidiumin ( 2 ), and kalidiumoside B ( 3 ). Their structures were elucidated through spectral studies including 2D‐NMR experiments (HMQC, HMBC, COSY, NOESY) and J‐resolved spectra. Also isolated were the two known compounds dianic acid and dianoside F, which were identified through comparison of their spectroscopic data with those reported in the literature.     

Triumfettosterol Id and Triumfettosaponin,a New (Fatty Acyl)‐Substituted Steroid and a Triterpenoid ‘Dimer’ Bis(β‐D‐glucopyranosyl) Ester from the Leaves of Wild Triumfetta cordifolia A. Rich. (Tiliaceae)

Two new triterpenoid derivatives were isolated from the leaves of wild Triumfetta cordifolia A. Rich . and identified to be a (fatty acyl)‐substituted steroid 1 and a triterpenoid saponin ‘dimer’ 2 , named (3β)‐stigmasta‐5,22‐diene‐3,29‐diol 3‐propanoate 29‐triacontanoate and (2α,3β,19α)‐2,3,19‐trimethoxyurs‐12‐ene‐24,28‐dioic acid 24‐[(2α,3β)‐24,28‐bis(β‐D ‐glucopyranosyloxy)‐2‐hydroxy‐24,28‐dioxours‐12‐en‐3‐yl] ester, respectively. These compounds were obtained together with a mixture of known sterols (stigmasterol/β‐sitosterol=(3β,22E)‐stigmasta‐5,22‐dien‐3‐ol/(3β)‐stigmast‐5‐en‐3‐ol) and trans‐tiliroside ( 3 ). The structures 1 and 2 were determined on the basis of NMR data (¹H‐, ¹³C‐, and 2D‐NMR analyses) and mass spectrometry and confirmed by chemical transformations. The antimicrobial activities of trans‐tiliroside ( 3 ) against eight bacterial and two fungal strains were evaluated. This compound showed weak activities on some bacterial strains.     

A New Megastigmane Palmitate and a New Oleanane Triterpenoid from Aster yomena Makino

A new megastigmane palmitate, 9‐oxomegastigm‐5(13)‐ene‐2β‐palmitate ( 1 ), and a new oleanane triterpenoid, (3β)‐3,23,28‐trihydroxyolean‐12‐en‐11‐one ( 2 ), together with three known oleanane‐type triterpenoids, β‐amyrin ( 3 ), erythrodiol ( 4 ), and (3β)‐olean‐12‐ene‐3,23,28‐triol ( 5 ), were isolated from the aerial parts of Aster yomena (Asteraceae). Their structures were identified based on 1D‐ and 2D‐NMR analysis, including ¹H,¹H‐COSY, HSQC, HMBC, and NOESY techniques.