欧洲李种子的化学成分研究

利用溶剂萃取和色谱分离手段,从蔷薇科植物欧洲李(Prunus domestica L.)种子中得到6个化合物。通过光谱分析,分别鉴定为松柏醛(1)、东莨菪亭(2)、(-)-二氢脱氢二松柏醇(3)、(-)-榕醛(4)、(E)-3,3’-二甲氧基-4,4’-二羟基茋(5)和5-羟甲基糠醛(6)。这些化合物均系首次从欧洲李种子中分离得到。     

桂林乌桕中的香豆素和鞣花酸类化合物

从桂林乌桕枝条的乙醇提取物中分离鉴定了8个已知化合物,经波谱分析确定其结构分别为：6,7,8-三甲氧基香豆素(1)、5,6,7,8-四甲氧基香豆素(2)、8-羟基-5,6,7-三甲氧基香豆素(3)、东莨菪内酯(4)、3,3’-二甲氧基鞣花酸(5)、4,4’-二甲氧基鞣花酸(6)、3,3’-二甲氧基鞣花酸-4-Oβ-D-木吡喃苷(7)、3,3’-二甲氧基鞣花酸-4-O-β-D-葡萄吡喃苷(8);其中化合物2,3,6,7,8均为首次从该属植物中分离得到。     

含硫香料——硫代芳樟醇及其衍生物的合成研究

本文对香叶醇转化为硫代芳樟醇(4)及其衍生物的合成方法进行了研究。香叶醇与N,N-二甲基琉代氨基甲酰氯反应生成N,N—二甲基琉代氨基甲酸-O-香叶基酯(5),(5)通过[3,3]-σ迁移反应转变成N,N-二甲基硫代氨基甲酸-S-芳樟基酯(6),(6)进一步还原得到硫代芳樟醇(4)。(4)转变成衍生物硫代芳樟醇乙酸酯(7a)及芳樟基甲基疏醚(7b)。(4)及(7b)在高度稀释时具有愉快的热带水果香味。     

10个马齿苋类型的脂肪酸和草酸含量分析

该研究采用气相色谱和比色法测定了10种不同来源马齿苋茎、叶中的脂肪酸和草酸含量。结果表明:(1)脂肪酸和草酸在10个不同类型马齿苋茎、叶中的含量均表现出一定的差异显著性。(2)与叶片相比,茎中的脂肪酸含量相对较低;马齿苋茎、叶中以多元不饱和脂肪酸为主;共测出两种多元不饱和脂肪酸,分别是亚麻酸(ω-3脂肪酸)和亚油酸(ω-6脂肪酸);不同类型马齿苋叶片和茎中ω-3和ω-6脂肪酸分别占脂肪酸总量的62.71%~70.91%和9.30%~13.31%,以及26.04%~36.02%和31.61%~43.19%,‘金湖’‘南阳’马齿苋叶片和‘金湖’马齿苋茎中!-3脂肪酸含量显著高于其他类型;国产马齿苋类型,尤其是茎中的!-6/!-3比例明显小于国外马齿苋类型。(3)马齿苋茎中的草酸含量明显高于叶;除‘山东’‘Iran’和‘Pakistan’马齿苋茎中的草酸显著积累外,其他类型马齿苋茎中的草酸含量差异不显著。因此,马齿苋适宜早采收;‘金湖’和‘南阳’,尤其是‘金湖’类型的马齿苋是一种值得研究和推荐的马齿苋类型。     

花叶中的新没食子酰黄酮甙和没食子丹宁

从花叶(Loropetalum chinense Oliv.)的70％Me_2CO提取物中经Toyopearl HW-40凝胶反复柱层析,得到3种没食子酰黄酮甙(LC-3,LC-13和LC-16),3种没食子丹宁(LC-20,LC-21和LC-22)和一种黄酮甙元(LC-14)。经化学和波谱分析,确定它们分别为黄芪甙-2’’-0-没食子酸酯(astragalin-2’’-0-gallate,LC-3,1)、黄芪甙-6’’-0-没食子酸酯(astragalin-6’’-0-gallate,LC-13,2)、黄芪甙-2’’,6’’-二-0-没食子酸酯(astragalin-2’’,6’’-di-0-gallate,LC-16,3)、八没食子酰葡萄糖(octagalloyl-glucose,8GG,LC-20)、六没食子酰葡萄糖(hexagalloyl-glucose,6GG,LC-21)、七没食子酰葡萄糖(heptagalloyl-glucose,7GG,LC-22)和木犀草素(luteolin,LC-14)。其中LC-16为一同时具有可水解丹宁和黄酮甙双重性质的新化合物,命名为花丁素(Loropetalin D,3)。上述成分均为首次从该植物中得到。     

嗜吡啶红球菌R04的联苯降解途径的研究

通过GC-MS测定出嗜吡啶红球菌R04菌降解联苯的中间代谢物2,3-二氢二羟基联苯、2,3-二羟基联苯和苯甲酸,并测定了该菌的2,3-二羟基联苯双加氧酶、2-羟基-6-酮基-6-苯基-2,3-己二烯酸(HOPDA)水解酶和苯甲酸双加氧酶活性。最终确定了R04菌降解联苯的途径为2,3-二羟基联苯双加氧酶途径。     

叶轮木的化学成分研究

从叶轮木的乙醇提取物中分离鉴定了10个已知化合物,经波谱分析确定其结构分别为：油酮酸(1)、豆甾醇-4-烯-3,6-二酮(2)、β-谷甾醇(3)、胡萝卜苷(4)、5,6-二羟基-3,3’,4’,7,8-五甲氧基黄酮(5)、没食子酸甲酯(6)、香草醛(7)、东莨菪内酯(8)、硬脂酸(9)、二十八碳醇(10)。以上化合物均为首次从该属植物中分离得到。     

十齿花化学成分研究

从十齿花的地上部分分离得到11个化合物,经理化方法和光谱分析鉴定为3,3'-二甲氧基鞣酸-4'-鼠李糖苷(1)、槲皮素-3-O-β-D-葡萄糖苷(2)、3,3'-二甲氧基鞣酸-4'-葡萄糖苷(3)、isolariciresinol-9-O-α-L-arabinopyranoside(4)、对苯二酚(5)、对羟基苯甲酸(6)、α-hydroxy-(4-hydroxyphenyl)acetonitrile(7)、6-O-methyldhurrin(8)、3,3',4',5,7-五羟基黄烷(9)、对羟基苯甲醛(10)、槲皮素-3-O-β-L-鼠李糖苷(11)。其中化合物2、4、6~11为该种首次分得。     

月见草中一个新的莽草酸衍生物CSCD

为了研究月见草Oenothera biennis L.的化学成分,采用硅胶、Sephadex LH-20凝胶、MCI gel CHP-20等柱色谱并结合半制备高效液相等分离技术,利用现代波谱学手段进行化合物结构鉴定。从月见草50%丙酮提取物中分离得到10个化合物,分别鉴定为dimethyl 3-lactyl shikimate(1)、methyl shikimate(2)、3,3′,4-O-三甲基鞣花酸(3)、3,3′-二甲氧基-鞣花酸(4)、3,4,3′-三甲氧基鞣花酸(5)、alternariol 9-methyl ether(6)、2,3-二羟基-1-(4-羟基-3,5-二甲氧基苯基)-1-丙酮(7)、scirpyrone H(8)、dimethoxydimethylphthalide(9)、clearanol C(10)。其中化合物1为新化合物,化合物2~10均为首次从该植物中分离得到。化合物2和3可显著提高TGF-β1诱导BEAS-2B细胞的活力,推测其具有潜在的肺保护作用。     

相思子化学成分研究

本研究从相思子种子的乙醇提取物中首次分离得到8个化合物,通过理化性质及光谱分析鉴定其结构为N-9-甲基-β-咔啉(1)、异喹啉酮(2)、吲哚-3-羧酸(3)、2,3-二甲氧基-5,7-二羟基-二氢黄酮(4)、3-羟甲基呋喃醛(5)、3-羟基-2-甲基-4-吡喃酮(6)、豆甾醇-4,22-二烯-3-酮(7)和(6E,6’E)-2-hydroxypropane-1,3-diylbis(octadec-6-enoate)(8)。同时还得到13个其他成分。     

Antimitotic activity and reversal of breast cancer resistance protein-mediated drug resistance by stilbenoids from Bletilla striata

Eight stilbenoids, 1-(p-hydroxybenzyl)-4,8-dimethoxyphenanthrene-2,7-diol (1), 2,7-dihydroxy-1,3-bis(p-hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene (2), 4,7-dihydroxy-1-(p-hydroxybenzyl)-2-methoxy-9,10-dihydrophenanthrene (3), 3,3'-dihydroxy-2',6'-bis(p-hydroxybenzyl)-5-methoxybibenzyl (4), 3',5-dihydroxy-2-(p-hydroxybenzyl)-3-methoxybibenzyl (5), blestriarenes B (6) and C (7), and blestrianol A (8) have been isolated by the guidance of inhibitory effect of tubulin polymerization from the tubers of Bletilla striata (Orchidaceae). Among them, both of bisbenzyls 4 and 5 inhibited the polymerization of tubulin at IC(50) 10muM, respectively. Furthermore bisbenzyl 4 potentiated the cytotoxicity of SN-38 in BCRP-transduced K562 (K562/BCRP) cells.     

Geranylated flavanones from the secretion on the surface of the immature fruits of Paulownia tomentosa

Chemical investigation of the methanol extract of the viscous secretion on the surface of immature fruits of Paulownia tomentosa furnished nine geranylated flavanones, 6-geranyl-5,7-dihydroxy-3',4'-dimethoxyflavanone (1), 6-geranyl-3',5,7-trihydroxy-4'-methoxyflavanone (2), 6-geranyl-4',5,7-trihydroxy-3',5'-dimethoxyflavanone (3), 6-geranyl-4',5,5',7-tetrahydroxy-3'-methoxyflavanone (4), 6-geranyl-3,3',5,7-tetrahydroxy-4'-methoxyflavanone (5), 4',5,5',7-tetrahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]-3'-methoxyflavanone (6), 3,3',4',5,7-pentahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]flavanone (7), 3,3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone (8), and 3,4',5,5',7-pentahydroxy-3'-methoxy-6-(3-methyl-2-butenyl)flavanone (9), along with six known geranylated flavanones. Among these, compounds 4, 6-9 and the known 6-geranyl-3',4',5,7-tetraahydroxyflavanone (diplacone), 6-geranyl-3,3',4',5,7-pentahydroxyflavanone (diplacol) and 3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone showed potent radical scavenging effects towards DPPH radicals.     

Sequential deiodination of thyroxine in rat liver homogenate.

Rat liver homogenate was incubated at 37 degrees C with thyroxine, 3,3',5-tri-iodothyronine, 3,3',5'-tri-iodothyronine or 3,3'-di-iodothyronine. The degradation or accumulation of these compounds was measured by specific radioimmunoassays. (1) Production of 3,3',5-tri-iodothyronine from thyroxine was highest at pH 6.0--6.5 and was markedly stimulated by the addition of dithiothreitol and effectively inhibited in the presence of 6-propyl-2-thiouracil. (2) Accumulation of 3,3',5'-tri-iodothyronine on incubation of thyroxine with homogenate was only observed above pH 8.5. Otherwise the product was converted into 3,3'-di-iodothyronine too rapidly to allow its measurement. By measuring 3,3'-di-iodothyronine it was deduced that 5-deiodination of thyroxine was most effective at approx. pH 8.0. Dithiothreitol powerfully stimulated this reaction and 6-propyl-2-thiouracil strongly inhibited. (3) Monodeiodination of the tyrosine ring of 3,3',5-tri-iodothyronine was the slowest reaction, was optimal at pH 8.0 and was less affected by dithiothreitol and 6-propyl-2-thiouracil than the above reactions. (4) 5'-Deiodination of 3,3',5'-tri-iodothyronine was extremely rapid, with a pH optimum probably at about 6.5. Owing to the high reaction rate under the conditions used it was not possible to assess the effects of dithiothreitol and 6-propyl-2-thiouracil.     

Methoxy-phenyl substituted ansa-titanocenes as potential anti-cancer drugs derived from fulvenes and titanium dichloride

Starting from 6-(4'-methoxyphenyl)fulvene (1a), 6-(2',4',6'-trimethoxyphenyl)fulvene (1b), or 6-(3',5'-dimethoxyphenyl)fulvene (1c), [1,2-di(cyclopentadienyl)-1,2-di(4'-methoxyphenyl)-ethanediyl] titanium dichloride (2a), [1,2-di(cyclopentadienyl)-1,2-bis(2',4',6'-trimethoxyphenyl)-ethanediyl] titanium dichloride (2b), and [1,2-di(cyclopentadienyl)-1,2-bis(3',5'-dimethoxyphenyl)-ethanediyl] titanium dichloride (2c) were synthesised. When titanocenes 2a-c were tested against pig kidney carcinoma cells (LLC-PK) inhibitory concentrations (IC50) of 2.8 x 10(-4), 3.6 x 10(-4) and 2.1 x 10(-4) M, respectively, were observed.     

Essential oil analysis of 10 Piperaceae species from the Brazilian Atlantic forest

Three new quercetin 3,3',4'-tri-O-beta-D-glucopyranosides isolated from leaves of Eruca sativa (Mill.) were identified as quercetin 3,3',4'-tri-O-beta-D-glucopyranoside, quercetin 3'-(6-sinapoyl-O-beta-D-glucopyranosyl)-3,4'-di-O-beta-D-glucopyranoside and quercetin 3-(2-sinapoyl-O-beta-D-glucopyranosyl)-3'-(6-sinapoyl-O-beta-D-glucopyranosyl)-4'-O-beta-D-glucopyranoside. The structures were established by one- and two-dimensional 1H and 13C NMR spectra as well as b     

Diprenylated chalcones and other constituents from the twigs of Dorstenia barteri var. subtriangularis

The twigs of Dorstenia barteri var. subtriangularis yielded three diprenylated chalcones: (-)-3-(3,3-dimethylallyl)-5'-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, (+)-3-(3,3-dimethylallyl)-4',5'-[2'-(1-hydroxy-1-methylethyl)-dihydrofurano]-4,2'-dihydroxychalcone and 3,4-(6",6"-dimethyldihydropyrano)-4',5'-[2',-(1-hydroxy-1-methylethyl)-dihydrofurano]-2'-hydroxychalcone for which the names bartericins A, B and C, respectively, are proposed. Stipulin, beta-sitosterol and its 3-beta-D-glucopyranosyl derivative were also isolated. The structures of these secondary metabolites were determined on the basis of spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. The structural relationship of bartericins B and C was further established by the chemical cyclization of one to the other.     

An anthraquinone and three naphthopyrone derivatives from Cassia pudibunda.

Chemical examination of the methanolic extract of the roots of Cassia pudibunda led to isolation of the new rubrofusarin-6-O-beta-D-glucopyranoside, quinquangulin-6-O-beta- D-apiofuranosyl-(1----6)-O-beta-D-glucopyranoside, quinquangulin-6-O-beta-D-glucopyranoside and chrysophanol dimethyl ether. Moreover the known chrysophanol, physcion, cis-3,3',5,5'-tetrahydroxy-4-methoxystilbene, trans-3,3',5,5' -tetrahydroxy-4-methoxystilbene, and cassiaside B were identified. The antimicrobial activity of some of these compounds is also reported.     

In vitro metabolism of polychlorinated biphenyl congeners by beluga whale (Delphinapterus leucas) and pilot whale (Globicephala melas) and relationship to cytochrome P450 expression

We measured rates of oxidative metabolism of two tetrachlorobiphenyl (TCB) congeners by hepatic microsomes of two marine mammal species, beluga whale and pilot whale, as related to content of selected cytochrome P450 (CYP) forms. Beluga liver microsomes oxidized 3,3',4,4'-TCB at rates averaging 21 and 5 pmol/min per mg for males and females, respectively, while pilot whale samples oxidized this congener at 0.3 pmol/min per mg or less. However, rates of 3,3',4,4'-TCB metabolism correlated with immunodetected CYP1A1 protein content in liver microsomes of both species. The CYP1A inhibitor alpha-naphthoflavone inhibited 3,3',4,4'-TCB metabolism by 40% in beluga, supporting a role for a cetacean CYP1A as a catalyst of this activity. Major metabolites of 3,3',4,4'-TCB generated by beluga liver microsomes were 4-OH-3,3',4',5-TCB and 5-OH-3,3',4,4'-TCB (98% of total), similar to metabolites formed by other species CYP1A1, and suggesting a 4,5-epoxide-TCB intermediate. Liver microsomes of both species metabolized 2,2',5,5'-TCB at rates of 0.2-1.5 pmol/min per mg. Both species also expressed microsomal proteins cross-reactive with antibodies raised against some mammalian CYP2Bs (rabbit; dog), but not others (rat; scup). Whether CYP2B homologues occur and function in cetaceans is uncertain. This study demonstrates that PCBs are metabolized to aqueous-soluble products by cetacean liver enzymes, and that in beluga, rates of metabolism of 3,3',4,4'-TCB are substantially greater than those of 2,2',5,5'-TCB. These directly measured rates generally support the view that PCB metabolism plays a role in shaping the distribution patterns of PCB residues found in cetacean tissue.     

Prenylated flavonoids from Moghania philippinensis

Five prenylated flavonoids, 8-(1,1-dimethylallyl)genistein (1), 5,7,3',4'-tetrahydroxy-2',5'-di(3-methylbut-2-enyl)isoflavone (2), 5,7,3'-trihydroxy-2'-(3-methylbut-2-enyl)-4',5'-(3,3-dimethylpyrano)isoflavone (3), (2R)-5,2',4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4a) and (2S)-5, 2', 4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4b), were isolated from the roots of Moghania philippinensis. The structures of these compounds were determined on the basis of spectroscopic and chemical means.     

Kinetics of enzymic reductive deiodination of iodothyronines. Effect of pH.

5'-Deiodination of thyroxine (yielding 3,3',5-tri-iodothyronine; reaction I) and of 3,3',5'-tri-iodothyronine (yielding 3,3'-di-iodothyronine; reaction II) and 5-deiodination of thyroxine (yielding 3,3',5'-tri-iodothyronine; reaction III) and of 3,3',5-tri-iodothyronine (yielding 3,3'-di-iodothyronine; reaction IV) as catalysed by rat liver microsomal fraction were studied at pH 6.5, 7.2 and 8.0 It was found that: (1) the Km of reaction I was relatively independent of pH (approx. 3 microM), whereas V was highest at pH 6.5 (63 pmol of 3,3',5-tri-iodothyronine/min per mg of protein); (2) the Km of reaction II was lowest at pH 6.5 (0.035 microM), but V was highest at pH 8.0 (829 pmol of 3,3'-di-iodothyronine/min per mg of protein); (3) thyroxine inhibited reaction II competitively; Ki values were identical at pH 6.5 and 8.0 (1 microM); (4) for both reactions III and IV Km was lowest and V was highest at pH 8.0. The results are compatible with the view that reactions I and II are mediated by a single enzyme (iodothyronine 5'-deiodinase) and that reactions III and IV are catalysed by a second enzyme (iodothyronine 5-deiodinase).