华根霉全细胞脂肪酶催化合成生物柴油

比较了5种不同商品化脂肪酶和自制的华根霉CCTCCM201021全细胞脂肪酶(RCL)催化油脂合成生物柴油的转化效果,结果表明,RCL能有效应用于无溶剂体系催化合成生物柴油.在无溶剂体系中对该酶催化生物柴油的转酯化反应工艺进行优化,考察了甲醇用量、体系含水量、酶的添加量和反应温度对生物柴油收率的影响,使生物柴油最终收率大于86.0%.在有机溶剂体系中选择不同有机溶剂作为助溶剂进行转酯化反应,发现logP值在4.0～4.5的有机溶剂具有较好的转化效果.其中以正庚烷为助溶剂的转酯化反应具有最高的生物柴油收率86.7%.在无溶剂体系中RCL催化转化油酸和模拟高酸价油脂合成脂肪酸甲酯的研究表明,该酶具有很好的催化合成生物柴油的潜力.     

A Study of the Constituents of the Heartwood of Tsuga Chinensis Pritz. Var. Formosana (Hay.)

By means of spectroscopic analysis, X-ray crystallography and chemical correlation the heartwood of Taiwan hemlock was found to contain compounds of sterols, carboxylic acids, 13-epimanool, o methoxyphenolics, coniferaldehyde, benzofuranoid neolignan, α-conidendrin, tsugacetal, isolariciresinol, secoisolariciresinol, matairesinol, hydroxymatairesinol and oxomatairesinol. Among them (+)-tsugacetal is a novel lignan acetal having an α-conidendrin related structure with the acetal methoxy group at the β-position.     

An alternative strategy based on ultra-high-performance supercritical fluid chromatography for full monosaccharide compositional analysis of polysaccharides in Schisandra chinensis fruits

Due to green and environment-friendly characteristics, ultra-high-performance supercritical fluid chromatography has been widely used in analytical fields in recent years, but until now few reports are available for monosaccharide compositional analysis of macromolecule polysaccharides. In this study, an ultra-high-performance supercritical fluid chromatography technology with an unusual binary modifier is used to determine the monosaccharide compositions of natural polysaccharides. Each carbohydrate herein is simultaneously labeled as 1-pheny-3-methyl-5-pyrazolone and acetyl-derivative via pre-column derivatizations aiming to increase UV absorption sensitivity and decrease water solubility. Ten common monosaccharides are fully separated and detected on ultra-high-performance supercritical fluid chromatography combined with a photo-diode array detector by systematic optimization of multiple relevant parameters, for example, column stationary phases, organic modifiers, additives, flow rates, and so on. Compared with carbon dioxide as a mobile phase, the addition of a binary modifier increases the resolution of analytes. Additionally, this method has the advantages of small consumption of organic solvent, safety, and being environmental-friendly. It has been successfully applied for full monosaccharide compositional analysis of heteropolysaccharides from Schisandra chinensis fruits. To sum up, a new alternative approach is provided for monosaccharide compositional analysis of natural polysaccharides.     

Five new bidesmoside triterpenoid saponins from Stauntonia chinensis

Eleven triterpenoid saponins (1-11) were isolated from Stauntonia chinensis DC. (Lardizabalaceae), including five new compounds, yemuoside YM(21-25) (1-3, 6, 7) structures of which were elucidated by chemical methods and a combination of MS, 1D- and 2D- NMR experiments including DEPT, (1)H--(1)H COSY, HSQC, HMBC, TOCSY, and NOESY as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonicacid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-xylopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (6), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-arabinopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (7).     

A New Flavonol Oligosaccharide from the Seeds of Aesculus chinensis

Aesculus chinensis is a traditional chinese medicinal plant widely distributed in China, which has been used to treat stomach disease. From recent research its seeds contain many flavonoids and proanthocyanidin A2, which have potential venotonic and vasoprotective action and powerful antioxidant activity. In this paper, we report the isolation and the structure elucidation of a new flavonol oligosacchride. Bioassay results showed that the compound exhibited an antivirus activity. …     

Cell extraction combined with off‐line HPLC for screening active compounds from Coptis chinensis

Cell membrane chromatography is a useful tool for screening active compounds from natural products. As the reason of separation mechanism, traditional cell membrane chromatography could not be used for screening the active compounds absorbed through the cell membrane and influencing the cell signal transduction pathway. In this work, we establish a new method named cell extraction combined with off‐line HPLC for screening the compounds penetrating the cell membrane. This is the first time 3 T3‐L1 adipocyte culture has been combined with HPLC technology. Compared with other cell membrane chromatography methods, there is good resolution and no further analysis by other chromatographic steps is required. On co‐incubating crude extracts of Coptis chinensis with cells and analyzing the compounds extracted by the cells, active compounds such as berberine were detected. Glucose consumption tests showed that berberine could increase glucose consumption by insulin‐resistant 3 T3‐L1 adipocytes. The levels of intracellular berberine correlated with its activity. The results indicate that the developed method could be an alternative method for screening active compounds from natural products. Copyright © 2015 John Wiley & Sons, Ltd.     

Two novel 2,5-diphenyl oxazole derivatives from Gymnotheca chinensis

Two novel 2,5-diphenyl oxazole derivatives, named gymnothecaoxazoles A (1) and B (2), were isolated from the whole parts of endemic medicinal plant of Gymnotheca chinensis (Saururaceae). The structures of the new compounds were elucidated by extensive NMR and MS data, and the structure of compound 1 was further confirmed by X-ray crystal diffraction analysis.     

Comparative pharmacokinetic profiles of five poorly soluble pulchinenosides in different formulations from Pulsatilla chinensis saponins extracts for enhanced bioavailability

Pulsatilla chinensis, a traditional Chinese medicine (TCM), has been used for treating amoebic diseases, vaginal trichomoniasis and bacterial infections over a long history. Now growing attention has been attracted to its antitumor activities. The purpose of this work was to compare the pharmacokinetic profiles of pulchinenosides in different formulations and to improve their oral bioavailability. Extracts of P. chinensis saponins were prepared for PRS‐Na (salt forming), PRS‐HPβCD (hydroxypropyl‐β‐cyclodextrin inclusion complex), PRS‐O/W (oil‐in‐water emulsion) and PRS‐silica (micronization), respectively. A simpler and more durable LC‐MS/MS method was developed in this study for quantitative analysis of pulsatilla sapoin D, B7, B10, B11 and sapoin PD simultaneously. The four formulations enhanced saponins oral bioavailability to varying degrees, as PRS‐HPβCD > PRS‐silica > PRS‐O/W > PRS‐Na, which indicated that water‐soluble preparations can obviously improve the solubility of saponins, and are helpful to increase bioavailability. In particular, hydroxypropyl‐β‐cyclodextrin inclusion complex was the most effective way to promote absorption of saponins, raising the F values (bioavailability) >20 times. Therefore, P. chinensis saponin molecules can be slowly released by emulsion and micronization, which can avoid the enormous C_max appearing in HPβCD, considering the pharmacokinetics profiles. However, appropriate pharmacokinetic parameters were observed in PRS‐Na, although the F value was minimum among the four preparations. Copyright © 2015 John Wiley & Sons, Ltd.     

Two isomeric compounds of C_(13)-norisoprenoids from Saururus chinensis(Lour.) Baill

Two new isomeric compounds of rare acyclic C_(13)-norisoprenoids,along with two known lignans sauchinone and licarin A,were isolated from the herb of Saururus chinensis(Lour.) Baill.Their structures were elucidated on the basis of spectral analysis.     

A new bidesmoside triterpenoid saponin from Stauntonia chinensis

A new bidesmoside triterpenoid saponin,named stauntoside C1(1) has been isolated from Stauntonia chinensis.Its structure was established by means of spectral and chemical methods.