柠檬桉叶化学成分研究(二报)——黄酮类化合物的分离鉴定

从柠檬桉(Eucalyptus citriodora)叶的醇提取物乙酸乙酯组分中分离提纯了五个黄酮类化合物,经物理和光谱方法鉴定为:槲皮素,杨梅树皮素以及它们的糖苷—槲皮索-3-O-葡萄糖苷,杨梅树皮素的3-O-鼠李糖苷和3-O-葡萄糖苷。此外从乙酸乙酯组分的水解液中,经纸层析检测有槲皮素和杨梅树皮素以及花青定和翠雀定存在,表明该组分中含上述黄酮醇及花青素的苷类化合物。     

核桃楸外果皮提取物的化感作用及成分分析

采用常规提取法浸提核桃楸外果皮的化感作用成分。研究结果表明,核桃楸外果皮乙醇提取物和乙酸乙酯萃取相对3种受体植物青菜、萝卜和紫花苜蓿具有化感作用(抑制萌发和抑制生长作用)。化感作用随提取物浓度增大而增大。采用GC-MS分析核桃楸外果皮乙醇提取物中乙酸乙酯萃取相的化学组成和相对含量。分析结果表明,核桃楸外果皮乙醇提取物中乙酸乙酯萃取相的主要化学成分为5-羟基-1,4-萘醌(胡桃醌),GC含量31.20%;正十六酸,GC含量9.99%;7-甲氧基-1-四氢萘酮,GC含量7.99%;1,5-萘二酚,GC含量7.15%;2,6-二甲氧基苯酚,GC含量4.36%;4-丁氧基苯醛;GC含量3.23%;5-羟甲基-2-呋喃醛,GC含量2.96%;二聚1,3-二羟基丙酮,GC含量2.94%;丙三醇,GC含量2.77%;1(3H)-异苯并呋喃酮,GC含量2.57%。     

Antimicrobial activity of extractives of Sarcocephalus coadunatus

The methanolic extracts and the fractions (petrol, dichloromethane, ethyl acetate, butanol) obtained from the leaves, seeds, stem and root barks of Sarcocephalus coadunatus exhibited a high level of broad spectrum antibacterial activity. The activity was more pronounced in the dichloromethane, ethyl acetate and butanol fractions of the leaves; ethyl acetate and butanol fractions of the seeds; dichloromethane fractions of the stem bark and the ethyl acetate fractions of the root bark. None of the fractions showed any antifungal activity.     

Antibacterial activity and cytotoxicity of Nyctanthes arbor-tristis flowers

The flowers of Nyctanthes arbor-tristis showed interesting antibacterial activity against some gram-positive and gram-negative microorganisms (chloroform and ethyl acetate extracts) and significant cytotoxic activity (petroleum ether, chloroform and ethyl acetate extracts).     

Antinociceptive activity of Maytenus rigida stem bark

Ethanol extract of Maytenus rigida stem bark and its fractions were assessed for antinociceptive activity in tail-flick test in rats. The activity was located in the chloroform, ethyl acetate and aq.methanol fractions. Phytochemical screening revealed that catechin was the only common class of compounds present on the ethanol extract as well as on the active fractions. 4'-Methylepigallocatechin, isolated from the ethyl acetate and aq.methanol fractions, showed antinociceptive effect in the tail-flick test (75 mg/kg; p.o.), which was reversed by the opiate antagonist naloxone (3 mg/kg; i.p.).     

苍耳对苹果轮纹病菌等的抑菌活性研究

以苍耳根、茎、叶作为试验材料,以丙酮、80%乙醇、乙酸乙酯、蒸馏水作为提取溶剂,利用滤纸片法研究了苍耳不同器官4种不同溶剂提取液对2种细菌和1种真菌的抑菌活性,结果表明:苍耳各器官的不同溶剂提取液抑菌效果不同。对溶剂来说,苍耳叶丙酮、乙酸乙酯提取液对枯草芽孢杆菌的抑菌圈直径分别达16.32mm、15.66mm,叶的乙酸乙酯提取液对苹果轮纹病菌的抑菌圈直径达15.64mm,4种不同溶剂提取液的总体抑菌活性由大到小依次为丙酮、乙酸乙酯、80%乙醇、蒸馏水;对不同器官来说,苍耳各器官提取液抑菌效果由大到小依次为叶、根、茎,尤以叶的丙酮提取液抑菌效果最佳,乙酸乙酯次之。苍耳叶的丙酮、乙酸乙酯提取液对枯草芽孢杆菌、苹果轮纹病菌均表现为较强的抑菌活性,但对大肠杆菌的抑菌活性较弱。     

Phytochemical and antimicrobial study of Chukrasia tabularis leaves

Successive petroleum ether, benzene, chloroform, ethyl acetate and methanol extracts of Chukrasia tabularis leaves were tested for their phytochemical constituents, antibacterial and antifungal activity. The ethyl acetate and methanol extracts were found to be most effective against most of the tested organisms.     

Antioxidant activity of Erica arborea

The antioxidant properties of the methanol extract of leaves and flowers of Erica arborea and the ethyl acetate, butanol and water soluble fractions were investigated. The ethyl acetate extract was found to be the richest for phenolic and flavonoid content which showed the highest antioxidant activity.     

Antimicrobial activity and cytotoxicity of Aerva lanata

Aerva lanata whole plant showed interesting antimicrobial activities (ethyl acetate and methanol extracts) and significant cytotoxic properties (petroleum ether, ethyl acetate and methanol extracts).     

Antimicrobial activity of Psychotria microlabastra.

The methanol extracts of leaves, root and stem barks of Psychotria microlabastra showed a broad spectrum of antibacterial activity, that was increased on fractionation (petrol, dichloromethane, ethyl acetate), particularly in the ethyl acetate fractions. None of the extractives showed activity against the tested moulds.     

Antimicrobial activity of Micrechites novoguineensis

The methanol extracts of Micrechites novoguineensis, leaves and stem bark were partitioned (petrol, ethyl acetate, methanol). All obtained fractions showed a broad spectrum of antibacterial activity, while only the leaf ethyl acetate fraction showed activity against moulds.     

不同溶剂抽提的竹醋液组分及含量研究

通过乙醚、二氯甲烷和乙酸乙酯3种有机溶剂对竹醋液抽提,利用气相色谱-质谱联用仪（GC-MS法）对抽提物的化学组分及其相对含量进行分析。结果表明：1）3种有机溶剂抽提后的竹醋液组分种类及含量存在着差异,采用乙醚抽提得到27种化合物,二氯甲烷抽提得到44种化合物,乙酸乙酯抽提得到58种化合物,化合物类型主要包括有机酸类、酚类、酮类、醇类、酯类、醛类及少量其他物质。2）选用乙酸乙酯抽提可以得到更多种类的酸类、酚类、酮类和醛类物质;选用二氯甲烷抽提则能获得相对成分含量更高的酸类和酚类物质;而乙醚更适于抽提醇类物质。     

Antimicrobial activity of Omalanthus nervosus

The ethanol extracts of Omalanthus nervosus leaves, stem and root barks, were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity, ethyl acetate fractions being in all cases the more active. No fraction was active against tested moulds.     

Antimicrobial activity of Clematis papuasica and Nauclea obversifolia.

The methanol extracts of Clematis papuasica leaves and stem bark and of Nauclea obversifolia leaves, stem and root barks showed awide spectrum of antibacterial activity which was increased on fractionation (petrol, dichloromethane, ethyl acetate), the ethyl acetate fractions being in all cases the most effective. None of the extractives was active against tested moulds.     

Antimicrobial activity of Harpullia ramiflora

The methanol extracts of Harpullia ramiflora, leaves, flowers, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity. The ethyl acetate fraction of the flowers exhibited the highest activity. No activity was shown against the tested moulds.     

Cytotoxicity and antileishmanial activity of Annona muricata pericarp

Hexane, ethyl acetate and methanol extracts of Annona muricata pericarp were tested in vitro against Leishmania braziliensis and L. panamensis promastigotes, and against cell line U-937. The ethyl acetate extract was more active than the other extracts and even of Glucantime used as reference substance. Its fractionation led to the isolation of three acetogenins--annonacin, annonacin A and annomuricin A.     

Antibacterial activity of Cichorium intybus

Antibacterial activity of the water, ethanol and ethyl acetate extracts of Cichorium intybus was investigated. All the tested extracts showed antibacterial activity, the ethyl acetate extract being the most active. Water extract inhibits Agrobacterium radiobacter sp. tumefaciens, Erwinia carotovora, Pseudomonas fluorescens and P. aeruginosa.     

Antioxidant and antimicrobial activities of Onosma argentatum and Rubia peregrina

The n-hexane-dichloromethane (1:1) extract of the roots of Onosma argentatum and the methanol extract (partitioned between water and chloroform, ethyl acetate and n-butanol, respectively), of the underground parts (roots and rhizomes) of Rubia peregrina were tested in vitro for their antioxidant and antimicrobial activities. The highest antioxidant activity (98%) was observed at 0.1% concentration for the roots of O. argentatum. It was 96% at 0.25% concentration on the ethyl acetate fraction of R. peregrina. O. argentatum extract was effective on Staphylococcus aureus, Bacillus subtilis and Escherichia coli. The ethyl acetate and chloroform fractions of R. peregrina were effective on S. aureus and E. coli, respectively. These two species did not have any antifungal activity.     

Antibacterial and antifungal activities of Angiopteris evecta

The leaves, stem bark, stem heart wood, root and tubers of Angiopteris evecta were successively extracted with petrol, dichloromethane, ethyl acetate, butanol and methanol. All the fractions exhibited a wider spectrum of antibacterial activity. The dichloromethane and ethyl acetate fractions of the leaves and stem bark were particularly good and were the only fractions exhibiting antifungal activity. All fractions of the tuber with the exception of petrol, exhibited very good antibacterial activity.     

Anti-microbial activity of Bidens pilosa, Bischofia javanica, Elmerillia papuana and Sigesbekia orientalis.

The ethanol extracts of Bidens pilosa (whole plant), Bischofia javanica (leaves), Elmerillia papuana (root bark) and Sigesbekia orientalis (whole plant) were partitioned (petrol, dichloromethane, ethyl acetate). The crude ethanolic extracts and all the obtained fractions showed a broad spectrum of antibacterial activity, the ethyl acetate fractions and the petrol fraction of E. papuana being the most effective. No activity was observed against the tested moulds.