类黄酮提取的基本原理、影响因素和传统方法

类黄酮广泛分布于植物界 ,具有显著的生物活性和药理作用 ,极具开发应用价值。但有关类黄酮提取的研究多是一些零星的报道 ,本文就类黄酮提取的基本原理、影响因素和传统方法进行了系统归纳和详细阐述 ,指出了每种传统方法的研究现状、存在的主要问题及今后的发展方向。

牧马豆中生物碱的提取分离及鉴定

采用醇类溶剂提取法和硅胶柱层析对牧马豆生物碱进行了提取、分离 ,得到了 3个单体化合物 (结晶 B、油状物 E、结晶 I)和 A、C、D、F、G、H六段生物碱混合物。结晶 B、油状物 E、结晶 I经红外光谱鉴定分别为黄华碱。

Studies on Triterpenoid Saponins of Seeds of Aesculus chinensis Bunge var. chekiangensis (Hu et Fang) Fang

Aim To study the saponin constituents of the seeds of Aesculus chinensis Bunge var. chekiangensis (Hu et Fang) Fang. Methods Compounds were separated and purified by macroreticular resin column chromatography and high-performance liquid chromatography. Their structures were elucidated by spectroscopic and hydrolysis analysis. Results Six compounds were isolated from the 70% ethanolic extracts. They were identified as escins IVc, IVd, Ia, Ib, isoescins Ia and Ib, respectively. Conclusion The above compounds were obtained from the seeds of Aesculus chinensis Bunge var.chekiangensis (Hu et Fang) Fang for the first time.

Steroids from green alga Chaetomorpha basiretorsa Setchell

Six steroids have been isolated from ethanolic extract of green alga Chaetomorpha basiretorsa Setchell by a combination of repeated normal phase silica gel and Sephadex LH-20 gel column chromatography as well as recrystallization. Using spectroscopic methods including MS and NMR, their structures were determined as β-1awsaritol （1）, saringosterol （2）, 24-hydroperoxy-24-vinyl- cholesterol （3）, β-stigmasterol （4）, stigmast-4-en-3α, 6β-diol （5）, 29-hydroxystigmasta-5, 24 （28）-dien-3β-ol （6）. All these compounds were obtained from this genus for the first time and they were inactive （IC50〉10μg/ml） against KB, Bel-7402, PC-3M, Ketr 3 and MCF-7 cell lines.

Evaluating the Effect of Algal Extracts against Ultraviolet B-Induced Skin Damage in BALB/c Mice

Ethanol extract of mixed algae--spirogyra and ulothrix was investigated to assess the effect on some biochemical parameters in UVB irradiated mice. The dorsal-thoracic region of mice were shaved and exposed to UVB radiation for 24 h for two consecutive weeks. Five groups of ten mice each were conducted： non-irradiated control and irradiated control. Mice treated with commercial cream （S.M.） at a dose of 0.1 mg/cm2 and mice treated with ethanol extract of mixed spirogyra and ulothrix at a dose of 0.1 mg/cm2 or 0.2 mg/cm2. Topical application was performed to all treated mice groups once a day for four consecutive weeks. Results showed significant differences between treated and control groups during the whole period of experiment. The clear potentiality of the ethanol extract was detected through body and skin weight, level of total protein, Superoxide Dismutase （SOD） and Catalase （CAT） activities in skin. However, UVB irradiated mice treated with 0.2 mg/cm2 exhibited the most significant effect when compared to control groups. That may be attributed to anti-inflammatory and anti-oxidant effects of algal extract.

Comparative Study on the Antibacterial Activity of Fresh and Fallen Leaves of Terminalia catappa L.

In the work reported here, the potential of different methods （cold and hot water, and ethanolic） of extraction of Indian almond （Terminalia catappa L.）, fresh and fallen leaves as an anti-bacterial agent was investigated. The hot water extract did not show any spectrum of activity against the selected bacteria while the cold water extract showed slight antibacterial activity suggesting that the effective components are heat labile. The ethanolic extracts of the leaves have higher antibiotic spectrum of activity than the cold water extract showing ethanol to be a better solvent in extracting the effective component. The fallen leaves seem to have a higher concentration of the effective component against the bacteria while ethanolic extract of the fresh leaves have similar spectrum of activity to Ciprofloxacin and Nitrofuratoin. These suggest that some effective components are lost when leaves fall off while some seem to increase in concentration. Fresh and fallen leaves contain tannin and flavonoids. In addition, the fallen leaves contain flavones. This might be responsible for the higher activity of fallen leaves extract observed against Pseudomonas and Staphylococcus spp. in our study. Combined use of extracts from fresh and fallen leaves broadened the spectrum of activity.

Study on Flavonoids and Triterpenoids Content of some Euphorbiaceae Plants

The Spurge family （Euphorbiaceae） is a large family of flowering plants. Two plant species of this family were collected from the Egyptian desert, extracted with methanol subjected to silica gel column chromatography to give six compounds, three compounds from each plant. The compounds isolated from the methanol extract of Euphorbia retusa Forssk were identified as kaempferol-3-beta-D glucopyranosyl （1）, 3-O-alpha-L-xylopyranosyl （1→3）-alpha-L xylopyranosyl （1→2）, beta-D glucopyranosyllup 1,12-diene-3,21-diol （2） and 5,7,8,3＇,4＇-pentahydroxy-3-methoxyflavone （3） and the compounds isolated from Euphorbia paralais L. identified as 3,5,3＇-trihydroxy-6,7-d-methoxy-4＇ （7＂-hydroxygeranyl-1＂-ether） flavones （4）, 3-O-syringic acid （1→4）-alpha-L- xylopyranosyl （1→3）, beta-D-rahminopyranosyl hederagenin （5） and 3-O-syringic acid （1→4）, beta-D-rahminopyranosyl （1→3）,beta-D-rahminopyranosyl hederagenin （6）. The structure of the isolated compounds was elucidated by chemical and spectrometric analysis such as Infera red （IR）, proton and carbon nuclear magnetic resonance （1H-, 13C-NMR） and chemical ionization mass spectrometry （CI-MS）.

Anti-promastigote Activity of the Amazon Plants

This study evaluated in vitro activity of ethanol extract, fractions, and isolated substance from Amazon species against promastigotes of L. amazonensis. The ethanol extracts were concentrated and fractionation. The anti-promastigote activity was evaluated through the cell viability assessment method （MTT）. The ethanol extract, fractions, and isolated substance from Himatanthus articulatus and Parahancorniafasciculata were inactive in promastigote ofL. amazonensis, as the ethanol extract ofPhysalis angulata. The hexane fractions from different parts ofMontrichardia linifera showed anti-promastigote activity probably due to the presence of steroids and terpenes. All species in studies were inactive, except ofM. linifera. The few polar constituents can be responsible for the activity. Therefore, the isolation and purification of the active on L. amazonensis promastigotes are urgently required.

Effect of Artemisia species on cellular proliferation and apoptosis in human breast cancer cells via estrogen receptor-related pathway

OBJECTIVE:To investigate the mechanism underlying the anticancer effect of Artemisia species through the inhibition of cell growth and induction of apoptosis in breast carcinoma cells.METHODS:To evaluate the anticancer activity of methanol extracts of eight Artemisia species(Artemisia stolonifera,Artemisia selengensis,Artemisia japonica,Artemisia Montana,Artemisia capillaris,Artemisia sylvatica,Artemisia keiskeana,and Artemisia scoparia),we first investigated the proliferation of estrogen receptor(ER)-positive MCF-7breast carcinoma cells exposed to 5 or 200 g/mL for72 h.Apoptosis induction was assessed by an Annexin V binding assay in cells exposed to extracts at a high concentration(200 g/mL).To verify the mechanism of apoptosis,ER expression and its related signaling was investigated using an immunoblot assay under the same conditions.RESULTS:MCF-7 cells showed the strongest antiproliferative response to the tested extracts.Howev-er,a biphasic effect was observed:the extracts inhibited proliferation at high concentrations whereas they stimulated it at low ones.ER expression was similarly modulated by the extracts.However,all of the extracts induced apoptosis at a high concentration(200 g/mL).Compared to the control level,exposure to the extracts resulted in a remarkable increase in the shift of cell populations.CONCLUSION:The present study suggests that the tested Artemisia species exerted their anticancer effects through the induction of apoptosis via an ER-related pathway.