A facile synthesis of (3α-3H]β-sitosterol

Direct oxidation of the parent sterol using CrO₂ provided (24R)-24-ethyl-5-cholesten-3-one which on treatment with NaBT₄ gave [3α-³H] (24R)-24-ethyl-5-cholesten-3β-ol. Purification at each stage afforded samples which were compared spectrally with the corresponding cholesterol series compounds.     

Two new resorcinol derivatives with strong cytotoxicity from the roots of Ardisia brevicaulis Diels

Two new resorcinol derivatives, 4-hydroxy-2-methoxy-6-[(8Z)-pentadec-8-en-1-yl]phenyl acetate (1) and 4-hydroxy-2-methoxy-6-pentadecylphenyl acetate (2), together with known compounds ardisiphenol D (3), 5-tridecylresorcinol (4), 5-pentadecylresorcinol (5), 5-[(8Z)-pentadec-8-en-1-yl]resorcinol (6), belamcandaquinones C and D (7 and 8, resp.), ardisicrenoside A, ardisiacrispin B, (22E)-24-ethyl-5α-cholesta-7,22-dien-3-one, and (22E)-24-ethyl-5α-cholesta-7,22-dien-3β-ol were isolated from the MeOH extract of the roots of Ardisia brevicaulis Diels. Their structures were determined by spectroscopic analysis including ESI- and EI-MS, and NMR data. Cytotoxicities of 1-4 against cell lines A549, MCF-7, and PANC-1 were tested in vitro by the MTT (=3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) method. Compounds 1-4 showed cytotoxic activity against all cell lines stronger than that of cisplatin against A549.     

Conversion of 7alpha-hydroxycholesterol and 7alpha-hydroxy-beta-sitosterol to 3alpha, 7alpha-dihydroxy- and 3alpha, 7alpha, 12alpha-trihydroxy-5beta-steroids in vitro.

The metabolism of 7alpha-hydroxycholesterol and 7alpha-hydroxy-beta-sitosterol (24alpha-ethyl-5-cholestene-3beta,7alpha-diol) has been compared in rat liver subcellular fractions. 7alpha-Hydroxy-beta-sitosterol was shown to be metabolized in the same manner as 7alpha-hydroxycholesterol. Thus, the following C29 metabolites have been identified: 24alpha-ethyl-7alpha-hydroxy-4-cholesten-3-one, 24alpha-ethyl-7alpha,12alpha-dihydroxy-4-cholesten-3-one, 24alpha-ethyl-7alpha-hydroxy-5beta-cholestan-3-one, 24alpha-ethyl-5beta-cholestane-3alpha,7alpha-diol, 24alpha-ethyl-7alpha,12alpha-dihydrozy-5beta-cholestan-3-one, and 24alpha-ethyl-5beta-cholestane-3alha,7alpha,12alpha-triol. The C29 compounds were generally less efficient substrates. The most pronounced difference was noted for the delta4-3-oxosteroid 5beta-reductase. Thus, 7alpha-hydroxy-4-cholesten-3-one was three to four times as efficiently reduced as the C29 analog. The oxidation of the 3beta,7alpha-dihydroxy-delta5-steroid to the 7alpha-hydroxy-delta4-3-oxosteroid, the 12alpha-hydroxylation of the 7alpha-hydroxy-delta4-3-oxosteroid, and the reduction of the 7alpha-hydroxy-5beta-3-oxosteroid to the 3alpha,7alpha-dihydroxy-5beta-steroid occurred in up to two times better yields for the C27 steroids.     

三种毒菌的化学成分研究

本文对三种毒菌的化学成分进行了研究。从光盖伞(Psilocybe spp)分离鉴定了4个化合物,经波谱分析鉴定为:(22E,24R)-麦角甾-7,22-二烯-3β-十八烷酸酯(1)、β-胡萝卜苷(2)、(22E,24R)-5α,6α-环氧麦角甾-8,22-二烯-3β,7α-二醇(3)、色氨酸(4);从假褐云斑鹅膏(Amanita pseudoporphyria)分离鉴定了4个化合物:(22E,24R)-3β-羟基-5α,8α-过氧化麦角甾-6,22-二烯(5)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(6)、1-O-β-D-吡喃葡萄糖基-(2S,3R,4E,8E,2′R)-2-N-(2′-羟基棕榈酰)-9-甲基-4,8-脱氢鞘氨醇(7)、1-O-β-D-吡喃葡萄糖基-(2S,3R,4E,8E,2′R)-2-N-(2′-羟基十八烷酰)-9-甲基-4,8-脱氢鞘氨醇(8);大青褶伞(Chlorophyllum molybdites)发酵菌丝体分离鉴定了4个化合物:5、6、(22E,24R)-5α,6α-环氧麦角甾-8(14),22-二烯-3β,7α-二醇(9)、(22E,24R)-麦角甾-7,22-二烯-3β-醇(10)。除化合物9外其它化合物均为首次从以上相应毒菌中分离得到。     

Novel tirucallane-type triterpenoids from Aphanamixis grandifolia

Phytochemical investigation on the stem bark of Aphanamixis grandifolia afforded five novel tirucallane-type triterpenoids, (13α,14β,17α,23Z)-25-methoxy-21,23-epoxylanosta-7,20(22),23-triene-3,21-dione (1), (13α,14β,17α,23Z)-21,23-epoxylanosta-7,20(22),23,25-tetraene-3,21-dione (2), (3R,5R, 9R,10R,13S,14S,17S)-17-{(2R,3S,5R)-5-[(2S)-3,3-dimethyloxiran-2-yl]-2,3,4,5-tetrahydro-2,5-dimethoxyfuran-3-yl}-4,4,10,13,14-pentamethyl-2,3,4,5,6,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol (3), (5R,9R,10R,13S,14S,17S)-17-{(2R,3S,5R)-5-[(2S)-3,3-dimethyloxiran-2-yl]-2,5-dimethoxytetrahydrofuran-3-yl}-1,2,4,5,6,9,10,11,12,13,14,15,16,17-tetradecahydro-4,4,10,13,14-pentamethyl-3H-cyclopenta[a]phenanthren-3-one (4), and (3α,13α,14β,17α,20S,23R)-23-ethoxy-3-hydroxy-21,23-epoxylanost-7-en-24-one (5). The (1) H- and (13) C-NMR spectra of all compounds were fully assigned using a combination of 2D-NMR experiments, including HSQC, HMBC, and ROESY sequences. The structure of 1 with the absolute configuration was determined by ECD calculation. Compounds 3 and 4 showed moderate activities against human MCF-7 and HeLa cancer cells.     

苋科植物的丛枝菌根

有些种子植物如莎草科、十字花科、灯心草科、藜科、石竹科等20余科,以往曾被认为不能或不易形成丛枝菌根(郭秀珍等,1989;刘润进等,2000).随着对菌根的深入研究,曾被认为是不易与菌根菌组合的湿地生植物、寄生性植物、或一年生植物都被发现是可以形成内生菌根的(Trappe等,1992).此外,Allen等(1989)研究证实,Salsola kali,Atriplex roseum等生长于沙漠、海滨的藜科植物,进行接种处理后,也能形成丛枝菌根.我们在西双版纳调查热带雨林植物的丛枝菌根状况时,偶然发现刺苋(Amaranthus spinosus Linn.)的根系受到了丛枝菌根真菌的侵染,因此,对苋科植物作了扩大采样调查.本文主要报道从热带采集的5属6种苋科植物的根受丛枝菌根真菌感染形成丛枝菌根(arbuscular mycorrhiza,AM)和这些植物根际士壤中的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)的状况.     

攀援孔药花化学成分研究

从攀援孔药花全草95%乙醇提取物中首次分离得到19个化合物,通过波谱数据或与已知物对照,它们分别鉴定为:(2S,3S,4R)-2-[(2R)-2-羟基-二十一酰胺基]-二十一烷-1,3,4-三醇(1)、(2S,3S,4R)-2-二十四酰胺基-十八烷-1,3,4-三醇(2)、胡萝卜甙(3)、β-谷甾醇(4)、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇(5)、6β-羟基-豆甾-4-烯-3-酮(6)、十六烷酸-1-甘油酯(7)、桦木酸(8)、大黄素(9)、二十二烷酸-1-甘油酯(10)、对羟基苯甲醛(11)、十七烷酸-1-甘油酯(12)、金色酰胺醇乙酸酯(13)、十九烷酸-1-甘油酯(14)、棕榈酸(15)(、E)-p-香豆酸(16)、(22E,24S)-24-甲基-5α-胆甾-7,22-二烯-3β,5α,6β-三醇(17)、2-去氧-β-蜕皮激素(18)和auranamide(19)。     

Selective oxidation of steroidal allylic alcohols

Pyridinium chlorochromate in CH₂Cl₂ containing pyridine (2%) at 2—3°C has been found to effect the high yield selective oxidation of the hydroxyl function of a number of steroidal allylic alcohols. Under these conditions the oxidation of cholest-4-cn-3β-ol to the corresponding ketone was effected in 92% yield. Only the allylic hydroxyl function of 5α-cholest-8(14)-ene-3β,15α-diol, 5α-cholest-8(14)ene-3β,15β-diol and 5α-cholest-8(14)-ene-3β,7β-diol was oxidized under these conditions to give the corresponding α,β-unsaturated ketones in high yields. 5α-Cholest-8(14)-ene-3β,7α,15α-triol gave 5α-cholest-8(14)-ene-3β,7α-diol-15-one in 82% yield. Attempted oxidations of the 5α-cholestan-3β,15α-diol and 5α-cholest-7-ene-3β,15α-diol, both lacking an allylic hydroxyl function, under these conditions, were unsuccessful. Selective oxidation of the allylic alcohol function of 5α-cholest-8(14)-ene-3β,15β-diol using activated manganese dioxide gave 5α-cholest-8(14)-en-3β-ol-15-one in high yield while oxidation of the corresponding 15α-hydroxy epimer using manganese dioxide was unsuccessful.     

Effect of ageing on sterol metabolism in potato tuber slices

When fresh potato tuber slices were incubated with [1-¹⁴C]-sodium acetate, cycloartenol was heavily labelled but no radioactivity was recovered in 24-methylene cycloartanol and free sterols. If potato slices were aged for 0–24 hr before feeding with radioactive acetate, a rapid increase of the label in the sterol precursors and the free sterols was observed. The free sterol content was 5 × higher after ageing for 24 hr. Isofucosterol synthesis was especially stimulated. The synthesis of sterols during the ageing process seems to be related to the appearance of a cycloartenol C24-methylase and may be linked to a biogenesis of membranes.Nomenclature: (1) 4,4,14α-trimethyl 9β, 19β-cyclo-5α-cholest-24-en 3β-ol; (2) 4,4,14α-trimethyl 9β, 19β-cyclo-5α-ergost-24(28)-en 3β-ol; (3) 4α,14α-dimethyl 9β,19β-cyclo 5α-ergost 24(28)-en 3β-ol; (4) 4α, 14α-dimethyl 5α-ergosta 8.24(28)-dien 3β-ol; (5) 4α-methyl 5α-ergosta 7,24(28)-dien 3β-ol; (6) ergosta 5,24(28)-dien 3β-ol; (7) stigmasta 5,Z-24(28)-dien 3β-ol; (8) (24R)-24 methyl cholest 5-en 3β-ol; (9) (24R)-24 ethyl cholest 5-en 3β-ol; (10) (24S)-24 ethyl cholesta 5,E-22(23)-dien 3β-ol; (11) cholest 5-en 3β-ol.     

担子菌地星菌丝体中一个新的甾醇酯

从担子菌地星(Astraeus hygrometricus)发酵培养菌丝体中分离得到一个新的多羟基甾醇酯,其化学结构通过波谱学方法包括二维核磁共振鉴定为:3β,5α-二羟基-(22E,24R)-麦角甾醇-7,22-二烯-6α-棕榈酸酯。同时还从该菌中分离得到其它三个甾醇类化合物。     

齿菌子实体的化学成分研究

利用硅胶柱层析和Sephadex LH-20凝胶柱层析分离手段,从高等真菌齿菌(Hydnellumsp.No.2)子实体的甲醇提取物中分离鉴定了7个化合物,经现代光谱学技术鉴定为麦角甾-7,22-二烯-3β-醇(1)、5α,8α-过氧麦角甾-6,22-二烯-3β-醇(2)、(22E,24R)-3β-羟基-24-甲基胆甾-5,22-二烯-7-酮(3)、对羟基苯甲酸甲酯(4)、(24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(5)、Tuberoside(6)和脑苷脂B(7)。化合物4、5、6、7为该属首次报道。     

高等真菌黑虎掌子实体的化学成分

黑虎掌 (Ｓａｒｃｏｄｏｎａｓｐｒａｔｕｍ (Ｂｅｒｋ .)Ｓ .Ｉｔｏ) ,又名香茸 ,是一种美味食用菌。近年来发现该属Ｓ .ｓｃａｂｒｏ ｓｕｓ (Ｆｒ.)Ｐ .Ｋａｒｓｔ.中含有对神经生长因子 (ＮＧＦ)的合成具有诱导作用的生物活性二萜 (Ｏｈｔ等 ,1998)。作为“高等真菌生物活性代谢产物研究”的一部分 ,我们对采自云南武定的样品进行了化学分析。从黑虎掌的新鲜子实体中分得 15个化合物。它们分别为ｃｅｒｅｂｒｏｓｉｄｅＢ (1) (12 0ｍｇ) ,阿洛酮糖腺苷(2 ) (12ｍｇ) ,三磷酸尿苷 (3) (7ｍｇ) ,尿嘧啶 (4 ) (12ｍｇ) ,腺嘌呤 (5 ) (8ｍ…     

海洋真菌Fusarium sp.次级代谢产物的研究

采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、开放ODS柱色谱以及HPLC等方法从海洋真菌Fusarium sp.的菌丝体中分离得到5个化合物,通过波谱数据及理化性质分别鉴定为3β,15β-二羟基-(22E,24R)-麦角甾-5,8(14),22-三烯-7-酮(1)、3β,5α,9α-三羟基-(22E,24R)-麦角甾-7,22-二烯-6-酮(2)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3)、5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(4)和丁二酸(5).其中化合物1和2首次从该属真菌中分离得到.     

角果胡椒的化学成分研究

从角果胡椒的乙醇提取物中分离得到6个甾醇,通过波谱方法鉴定它们的结构为5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(1),(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(2),(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3),豆甾醇-5,11-二烯-3β-醇(4),豆甾醇-3,6-二酮(5),sitoindosideΙ(6)。     

褐薄小齿菌的化学成分研究

从褐薄小齿菌(Hydnellum concrescens)子实体中分离得到9个已知化合物,借助光谱手段,它们的化学结构分别鉴定为:friedelin(1),(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(2),5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(3),(22E,24R)-麦角甾-5,22-二烯-3β-羟基-7-酮(4),6-甲氧基-cerevisterol(5),thelephantin K(6),thelephantin I(7),thelephantin J(8),thelephantin L(9)。     

Side-chain cleavage of C27-3-oxo-4-ene sterols

In this study various C27 sterols with a 3-oxo-4-ene structure were incubated with adrenal cortex mitochondrial preparations. (22R)-22-Hydroxy-4-cholesten-3-one and (20R,22R)-20,22-dihydroxy-4-cholesten-3-one were found to be converted into progesterone. This suggests the existence of a pathway for adrenal progesterone formation analogous to the normal 3 beta-hydroxy-5-ene pathways. (20S)-20-Hydroxy-4-cholesten-3-one was hydroxylated at C25. 4-Cholesten-3-one, 25-hydroxy-4-cholesten-3-one and (22S)-22-hydroxy-4-cholesten-3-one were not converted to a measurable extent. With 3-oxo-4-ene C27 sterols as substrates, the cholesterol side-chain cleaving enzyme system seems to require the presence of a 22R-hydroxyl group in the substrate. The clinical relevance of these observations is discussed.     

Bile acid biosynthesis: the metabolism of 7 alpha-hydroxy-4-cholesten-3-one in the bile fistula rat.

The two primary bile acids, cholic acid (3α,7α,12α-tri-hydroxy-5β-cholan-24-oic acid) and chenodeoxycholic acid (3α,7α-dihydroxy-5β-cholan-24-oic acid), are initially synthesized by way of identical precursors, and the point of divergence of this pathway is thought to occur at the intermediate 7α-hydroxy-4-cholesten-3-one. In order to test this hypothesis, bile fistula rats received simultaneous intra-venous infusions of ³H-7α-hydroxy-4-cholesten-3-one and ¹⁴C-cholesterol (5-cholesten-3β-ol). Assays of equal specific activities of the two bile acids from an infusion of ¹⁴C-cholesterol demonstrated the achievement of a steady state, and assays of equal specific activities from an infusion of ³H-7α-hydroxy-4-cholesten-3-one would-validate the above postulate. However, the infusion of ³H-7α-hydroxy-4-cholesten-3-one resulted in unequal specific activities in the bile acids of the rats investigated, with cholic acid always of a lower value. These results suggest that either 7α-hydroxy-4-cholesten-3-one is not the last common intermediate in the production of cholic acid and chenodeoxycholic acid, or that the infused bile acid intermediate was not metabolized in a fashion similar to that formed in the liver from cholesterol.     

Dehydroxylation of a 7 beta-hydroxy-C27 plant sterol in rat liver

(22R)-Cholest-5-ene-3 beta,7 alpha,22-triol and the isomeric (22R)-cholest-5-ene-3 beta,7 beta,2-triol were 7-dehydroxylated by rat liver microsomes, after addition of NAD+ to the incubations. The product from both sterols was identified as (22R)-22-hydroxycholesta-4,6-dien-3-one by gas chromatography-mass spectrometry. The overall conversion of the 7 alpha-compound had an apparent Vmax of 5 nmol/mg protein per h, about 3-times higher than that of the 7 beta-isomer. Km was about 0.018 mmol/l in both reactions. NAD+ was required for the 7-dehydroxylation to proceed, conceivably by serving as cofactor in formation of the intermediate 7 beta,2-dihydroxy-4-cholesten-3-one. EDTA had a stimulatory effect upon the product formation. 7 alpha-Dehydroxylation of the bile acid precursor 7 alpha-hydroxy-4-cholesten-3-one has been demonstrated in liver tissue, but a 7 beta-hydroxy-C27-steroid dehydroxylating enzyme has previously not been identified. The results are discussed in relation to the marked differences in effect on neoplastic growth by the two isomeric hydroxysterols.     

Three new polyhydroxysteroids from the tropical starfish Asteropsis carinifera

Thirteen steroidal compounds including three new polyhydroxysteroids, (24R,25S)-24-methyl-5α-cholestane-3β,6α,8,15β,16β,26-hexaol, (22E,24R,25S)-24-methyl-5α-cholest-22-ene-3β,6α,8,15β,16β,26-hexaol and (22E,24R,25S)-24-methyl-5α-cholest-22-ene-3β,4β,6α,8,15β,16β,26-heptaol, have been isolated along with the previously known ten polyhydroxysteroids from the tropical starfish Asteropsis carinifera collected near the coast of Vietnam. The structures of new compounds were elucidated by spectroscopic methods (mainly 2D NMR and ESI-mass-spectrometry).     

Syntheses of 19-[O-(carboxymethyl)oxime] haptens of epipregnanolone and pregnanolone

O-(Carboxymethyl)oximes 1 and 2 derived from two epimeric 5beta-pregnanolones (3beta-hydroxy-5beta-pregnan-20-one and 3alpha-hydroxy-5beta-pregnan-20-one) in position 19 were prepared. Two synthetic routes were employed, both using protection of the 20-keto group after reduction into the (20R)-alcohol in the form of acetate. In the first route, (20R)-19-hydroxy-5beta-pregnan-3beta,20-diyl diacetate (3) was transformed into the corresponding 19-[O-(carboxymethyl)oxime] methyl ester 6, then deacetylated by acid and partially silylated with tert-butyldimethylsilyl chloride. The desired 3-O-silylated derivative 8 was separated, oxidized to the 20-ketone and protecting groups were sequentially removed to give the first title hapten 1. The second route started from (20R)-19-hydroxy-3-oxopregn-4-en-20-yl acetate (11), which was hydrogenated in the presence of base to the 5beta-pregnan-3-one derivative 12, protected in position 19 with tert-butyldimethylsilyl group and reduced with borohydride. The prevailing 3alpha-alcohol 15 was separated, protected in position 3 with a methoxymethyl group, deprotected in position 19 and transformed into the 19-[O-(carboxymethyl)oxime] 19. After deacetylation, esterification with diazomethane and oxidation in position 20, the pregnanolone skeleton was regenerated. Final deprotection steps gave the second title hapten 2. Both haptens, i.e., (19E)-3beta- and -3alpha-hydroxy-20-oxo-5beta-pregnan-19-al 19-[O-(carboxymethyl)oxime], were designed for the development of immunoassays of the corresponding parent neuroactive steroids.