The effect of calcium nutrition on the sterol content of tobacco roots and their susceptibility to Phytophthora parasitica var. nicotianae

The influence of nutrient solutions containing low (25 mg/1) and high (250 mg/1) calcium (Ca) concentrations on the total lipid, free sterol, sterol glycoside and steryl ester content and on the subsequent susceptibility of three flue‐cured tobacco cultivars to black shank, incited by Phytophthora parasitica var. nicotianae was investigated. The total lipid, total sterol and free sterol content differed appreciably among root systems of the three cultivars grown at high Ca. Roots of plants grown at low Ca contained relatively higher proportions of steryl glycosides and lower proportions of free sterols than roots of plants grown at high Ca, although the absolute sterol concentrations also differed significantly among the roots of cultivars grown at low Ca. Black shank disease development was significantly lower in roots of susceptible plants grown at low Ca than in roots of the same cultivar grown at high Ca. The innate susceptibility of the cultivars were not related to the lipid or sterol content. The reduced disease development of plants grown at low Ca appeared to be associated with changes in membrane permeability, which may be correlated with changes in the various sterol fractions.     

猴头菌小分子活性成分研究进展

综述猴头菌(Hericium erinaceus)小分子活性成分的研究进展,旨在为这类物质的进一步开发利用提供参考。     

The Role of Spongia sp. in the Discovery of Marine Lead Compounds

A comprehensive review on the chemistry of Spongia sp. is here presented, together with the biological activity of the isolated compounds. The compounds are grouped in sesquiterpene quinones, diterpenes, C21 and other linear furanoterpenes, sesterterpenes, sterols (including secosterols), macrolides and miscellaneous compounds. Among other reports we include studies on the intraspecific diversity of a Mediterranean species, compounds isolated from associated sponge and nudibranch and compounds isolated from S. zimocca and the red seaweed Laurentia microcladia. Under biological activity a table of the reported biological activities of the various compounds and the biological screening of extracts are described. The present review covers the literature from 1971 to 2015.     

分子短程蒸馏和重结晶分离银杏叶甾醇类化合物的研究

以银杏叶为原料,制备其石油醚提取软膏,通过皂化、萃取和冷冻,除去脂肪酸及其酯、蜡质等杂质,分离甾醇类集分.采用分子蒸馏分离技术和溶剂重结晶纯化甾醇类化合物,银杏叶甾醇收率为0.03%～0.08%.利用GC-MS联用技术鉴定银杏叶甾醇结晶物的化学组成,共分离出17种化合物,其中8种是甾醇类化合物,占所有峰面积的97.633%,依次为β-谷甾醇(67.984%)、8-烯-3β-麦角甾醇(10.624%)、3β-豆甾烷醇(10.065%)、5,24-二烯-3β-豆甾醇(5.255%)、4,22-二烯-3β-豆甾醇(1.926%)、5,8,22 E-三烯-3β-麦角甾醇(0.618%)、岩藻甾醇(0.595%)、α-谷甾醇(0.566%);酮类化合物占1.066%,分别为17,19-二乙酰氧基-4,4-二甲基-3α-雄-5,7-二烯-3-烷酮(0.336%)和17α-乙酰氧基孕烯醇酮(0.730%).除β-谷甾醇外,其它银杏叶甾醇均为首次报道.     

Resistance to Sterol Demethylation Inhibitors in Ustilago maydis. III. Cross-Resistance Patterns and Sterol Analyses

Two spontaneous triadimefon-resistant mutants of Ustilago maydis, 151ar/1 and 151ar/3, were investigated with regard to their extent of cross-resistance and their sterol composition to elicit indications about the specificity of the present resistance mechanisms. Testing resistance to various sterol biosynthesis inhibitors and toxicants with different modes of action, it could be demonstrated that, in the mutant 151ar/1, cross-resistance was limited to the sterol demethylation inhibitors (DMIs), whereas, in strain 151ar/3, resistance included most sterol biosynthesis inhibitors studied (DMIs, morpholines, piperidines, allylamines) as well as the unrelated compounds vinclozolin and cycloheximide. Sterol analyses showed that both mutants contained ergosterol as the main sterol component. In comparison with the sensitive reference strain, the mutant 151ar/1 had a slightly elevated content of C-14 methyl sterols, whereas in strain 151ar/3 the amount of ergosterol was increased. Triadimefon caused an accumulation of C-14 methyl sterols and a decrease in ergosterol content in the sensitive strain and the mutant 151ar/1, whereas the other strain 151ar/3 remained unaffected. The results indicate that several resistance mechanisms are probably operating in the two mutants.     

Sterol composition in polyene antibiotic-sensitive and resistant strains ofMalassezia pachydermatis

The membrane sterol compositions of ten strains ofMalassezia pachydermatis were analysed by gas-liquid chromatography. Six of these were wild-type strains from clinical sources that were sensitive to polyene antibiotics, whereas the other four strains were resistant mutants that had arisen after treatment withN-methyl-N-nitrosoguanidine or UV radiation.The wild-type strains contained 838.8 to 1291.7 µg of sterol per gram of freeze-dried mycelium. The sterols were composed of 79% ergosterol, 19% fecosterol and 2% lichesterol. The mutant strains contained 277.1 to 348.8 µg/g of sterols composed of 76% ergosterol and 24% fecosterol.Abbreviations MIC minimum inhibitory concentration - UV ultraviolet     

柑桔抗溃疡病品种叶细胞膜脂组分的研究

柑桔溃疡病（ｃｉｔｒｕｓｂａｃｔｅｒｉａｌｃａｎｋｅｒｄｉｓｅａｓｅ，ＣＢＣＤ）是由ＸａｎｔｈｏｍｏｎａｓｃａｍｐｅｓｔｒｉｓＰｖ．ｃｉｔｒｉ（ＸＣＣ）引发的。本研究检测了抗ＣＢＣＤ柑桔品种和对Ｘｃｃ敏感品种叶细胞膜脂组分及含量。抗病品种及敏感品种之叶细胞膜脂种类相似，主要为磷脂酰胆碱（ＰＣ）、磷脂酰乙醇胺（ＰＥ）、磷脂酰甘油（ＰＧ）和磷脂酰肌醇（ＰＩ），其中ＰＣ和ＰＥ占总量的７５％以上，尤以ＰＣ居首。抗病品种ＰＣ、ＰＥ、ＰＧ、ＰＩ总含量（１．２４～１．６５ｍｇ／ｇＦＷ）明显小于敏感品种（２．３２～５．０８ｍｇ／ｇＦＷ）；抗病品种磷脂分子中的不饱和脂肪酸（油酸、亚油酸和亚麻酸）与饱和脂肪酸（软脂酸和硬脂酸）的比率也小于敏感品种。抗ＣＢＣＤ品种和对ＸＣＣ敏感品种的叶细胞膜都含有显量的游离甾醇（０．５９～１．０１ｍｇ／ｇＦＷ）和痕量的甾醇酯。检出的游离甾醇主要有β－谷甾醇、菜油甾醇和羊毛甾醇，其中以β－谷甾醇含量最高，占总甾醇量的６０％以上。抗病品种的游离β－谷甾醇比敏感品种高３０％左右。各抗病品种叶细胞膜脂中的游离甾醇与总磷脂的比率（０．５２～０．７４）均显著高于敏感品种（０．１２～０．２８）。     

Mirabolides A and B; New Cytotoxic Glycerides from the Red Sea Sponge Theonella mirabilis

As a part of our continuing work to find out bioactive lead molecules from marine invertebrates, the CHCl₃ fraction of the organic extract of the Red Sea sponge Theonella mirabilis showed cytotoxic activity in our primary screen. Bioassay-guided purification of the active fractions of the sponge’s extract resulted in the isolation of two new glycerides, mirabolides A and B (1 and 2), together with the reported 4-methylene sterols, conicasterol (3) and swinhosterol B (4). The structures of the compounds were assigned by interpretation of their 1D (¹H, ¹³C), 2D (COSY, HSQC, HMBC, ROESY) NMR spectral data and high-resolution mass determinations. Compounds 1–4 displayed marked cytotoxic activity against human breast adenocarcinoma cell line (MCF-7) with IC₅₀ values of 16.4, 5.18, 6.23 and 3.0 μg/mL, respectively, compared to 5.4 μg/mL observed by doxorubicin as reference drug.     

冠瘤海鞘化学成分研究

[目的]研究海洋动物冠瘤海鞘的化学成分。[方法]采用硅胶柱色谱、Sephadex LH-20柱色谱、气相色谱等方法对冠瘤海鞘的化学成分进行分离纯化;运用波谱分析并结合文献鉴定化合物的结构。[结果]从冠瘤海鞘分离纯化得到白色针状晶体和无色油状物;白色针状晶体具有典型甾醇类化合物特征,其GC总离子流谱图与文献报道相似;无色油状物Rf值为0.5,10%浓硫酸显紫红色,核磁共振测定与文献报道的油酸甲酯相等。[结论]从冠瘤海鞘中分得混合甾醇和油酸甲酯,油酸甲酯为首次从该动物中分得。     

Phallusiasterols A and B: Two New Sulfated Sterols from the Mediterranean Tunicate Phallusia fumigata and Their Effects as Modulators of the PXR Receptor

Purification of the apolar extracts of the marine ascidian Phallusia fumigata, afforded two new sulfated sterols, phallusiasterols A (1) and B (2). The structures of the new compounds have been elucidated using mass spectrometry and NMR experiments. The effects of phallusiasterols A and B as modulators of pregnane-X-receptor (PXR) have been investigated. These studies revealed that phallusiasterol A induces PXR transactivation in HepG2 cells and stimulates the expression of the PXR target genes CYP3A4 and MDR1 in the same cell line. Molecular docking calculations suggested the theoretical binding mode of phallusiasterol A with hPXR and revealed that phallusiasterol A fitted well in the LBD of PXR.