核桃楸叶乙醇提取物的抑菌活性及活性成分分析

采用常规提取法浸提核桃楸叶的抑菌活性成分。研究结果表明,核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌和樟子松枯梢病菌有抑菌活性,核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌的最低抑菌质量浓度(MIC)为3.12 g/L,对樟子松枯梢病菌的MIC为6.25 g/L。采用GC-MS分析了核桃楸叶乙醇提取物中乙酸乙酯萃取相经柱层析后集分I和集分II的化学组成和相对含量。分析结果表明,乙酸乙酯萃取相中主要活性成分为相对含量较高的5-羟基-1,4-萘醌(胡桃醌)、D-阿洛糖、5,8-二羟基-1,4-萘醌、1,5-萘二酚、2,3-二氢苯并呋喃、7-甲氧基-1-四氢萘酮、1-萘酚、8-羟基-2-甲氧基-1,4-萘醌和4-甲基-2,6-二羟基喹啉等。     

核桃楸叶乙醇提取物的抑茵活性及活性成分分析

采用常规提取法浸提核桃楸叶的抑菌活性成分。研究结果表明，核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌和樟子松枯梢病菌有抑菌活性，核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌的最低抑菌质量浓度（MIC）为3．12g／L，对樟子松枯梢病菌的MIC为6．25g／L。采用GC-MS分析了核桃楸叶乙醇提取物中乙酸乙酯萃取相经柱层析后集分I和集分Ⅱ的化学组成和相对含量。分析结果表明，乙酸乙酯萃取相中主要活性成分为相对含量较高的5-羟基-1，4-萘醌（胡桃醌）、D-阿洛糖、5，8-二羟基-1，4-萘醌、1，5-萘二酚、2，3-二氢苯并呋喃、7-甲氧基-1-四氢萘酮、1-萘酚、8-羟基-2-甲氧基-1，4-萘醌和4-甲基-2，6-二羟基喹啉等。     

白三叶草黄酮含量及其抑菌活性研究

测定了白三叶草提取物的石油醚相、氯仿相、乙酸乙酯相和水相的黄酮含量,并以大肠杆菌、枯草芽孢杆菌、普通变形杆菌、金黄色葡萄球菌和铜绿假单胞菌5种细菌及可可葡萄座腔菌、尖孢镰刀菌、腐皮镰刀菌、多主棒孢霉和尖孢炭疽菌5种真菌为供试菌,采用抑菌圈法和抑制菌丝生长速率法测定了其抑菌活性。结果表明:石油醚相的黄酮含量为12.98 mg/g(12.98%),氯仿相的黄酮含量为13.89 mg/g(13.89%),乙酸乙酯相的黄酮含量为7.4 mg/g(7.4%),水相的黄酮含量为1.5 mg/g(1.5%);石油醚相对5种细菌无明显的抑制作用,氯仿相对普通变形杆菌和铜绿假单胞菌有抑制作用,其最低抑菌浓度(MIC)分别为2 mg/m L和8 mg/m L;乙酸乙酯相对枯草芽孢杆菌、普通变形杆菌和铜绿假单胞菌的有抑制作用,其最低抑菌浓度(MIC)分别为4,4和8mg/m L,仅水相对5种供试菌株有不同程度的抑制作用。氯仿相和乙酸乙酯相对5种真菌均具有抑制作用,氯仿相对5种供试真菌的抑制作用没有明显差异,其EC50分别为3.54、6.42、8.45、3.63和5.90 mg/m L;乙酸乙酯相对多主棒孢霉的抑制抑制作用最强,EC50为2.51 mg/m L,对尖孢镰刀菌的抑制作用最弱,EC50为165.43mg/m L,石油醚相和水相对5种真菌均无抑制作用。     

滇白珠种子抗炎化学成分的研究

采用小鼠耳肿胀法对滇白珠种子75%乙醇提取物的石油醚、氯仿、乙酸乙酯、正丁醇萃取物和水溶部分的抗炎效果进行测试。结果表明乙酸乙酯萃取物能显著减轻二甲苯致炎小鼠的耳廓肿胀度。采用色谱技术分离抗炎效果较好的乙酸乙酯萃取物的化学成分,得到8个化合物。通过NMR、IR、MS等波谱法鉴定,8个化合物为:大黄素甲醚(1)、6-乙基-5-羟基-2,7-二甲氧基-1,4-萘醌(2)、杨梅素(3)、对苯二酚(4)、香草酸(5)、β-胡萝卜苷(6)、β-谷甾醇(7)和丁二酸(8)。以上所有化合物都为首次从滇白珠种子中分离得到。     

鹿角藤提取物的抑菌活性

采用生长速率法测定鹿角藤甲醇粗提物、石油醚、氯仿、乙酸乙酯、正丁醇4种溶剂萃取物及氯仿萃取物的层析组分对6种靶标菌的抑菌活性。结果表明,在质量浓度5 mg·m L-1条件下,4种萃取物中,氯仿萃取物的抑菌活性最好,尤其是对香蕉炭疽菌及芒果炭疽菌,其抑制率达82.48%、71.57%;氯仿萃取物的进一步层析组分中,E组分的抑菌活性最好,且具有广谱抑菌活性,在质量浓度0.5 mg·m L-1条件下,组分E对香蕉炭疽菌的抑制率达74.12%,具有进一步研究开发的潜质。     

几种桉叶提取物的抗菌活性研究

研究了大叶桉、柠檬桉、尤曼桉(A、B)叶乙醇提取物和大叶桉、尤曼桉B叶提取物浓缩浸膏的石油醚、乙酸乙酯和正丁醇萃取组分对金黄葡萄球菌、大肠杆菌、枯草芽孢杆菌、黄瓜枯萎病菌的抗菌活性和以及这几种桉叶提取物的最低抑菌浓度。结果表明4种桉叶提取物对4种供试菌均有抑制作用,对金黄葡萄球菌、枯草芽孢杆菌抑制作用强,对黄瓜枯萎病菌作用弱。大叶桉、尤曼桉B提取物的抗菌活性强,这两种桉叶的乙酸乙酯和正丁醇萃取组分对4种供试菌抑菌作用最明显。     

美洲大蠊乙酸乙酯提取物的分离和抑菌活性分析

采用活性追踪法和柱层析法,以金黄色葡萄球菌、大肠杆菌等5种细菌为供试菌种,对美洲大蠊乙酸乙酯提取物进行分离和抑菌试验.研究发现:美洲大蠊乙酸乙酯提取物对供试的革兰氏阳性菌具有一定的抑制作用,其中,对枯草芽孢杆菌的抑菌活性最好;经硅胶柱层析初分离后,从乙酸乙酯提取物获得了9个具有抑菌活性的组分,其中,组分Fr7对5种供试菌均显示了较好的抑菌活性;组分Fr7及其相邻组分Fr8经硅胶和凝胶柱层析进一步分离纯化后,得到了7个具有抑菌活性的不饱和脂肪酸类化合物,均对藤黄微球菌表现出最好的抑菌活性.结果表明:美洲大蠊乙酸乙酯提取物的抑菌活性物质为不饱和脂肪酸类化合物,对供试的革兰氏阳性菌的抑菌活性较强.     

肉桂和同源根皮不同极性部位的成分分析及其抑菌效果

以肉桂及其同源根皮为原料,采用80%乙醇分别对两者进行回流提取,经系统溶剂法萃取得到两者的石油醚部位、乙酸乙酯部位、正丁醇部位和水部位,并采用滤纸片法研究各极性部位对常见的3种致病菌(金黄色葡萄球菌、大肠杆菌、绿脓杆菌)的抑菌活性。研究结果表明:相同质量的肉桂和根皮提取得到的各极性部位的质量、成分种类及含量均有所差异,其中石油醚部位所含成分大致相同,但主要成分反式肉桂醛、邻甲氧基肉桂醛含量差异较大;两者乙酸乙酯部位、正丁醇部位和水部位分别含有黄酮类,皂苷类和多糖类成分;此外根皮乙酸乙酯部位还含有邻甲氧基肉桂醛、乙酸肉桂酯,根皮水部位含有D-半乳糖。肉桂石油醚部位、根皮石油醚部位、根皮乙酸乙酯部位对3种菌均有一定的抑制作用,当这3个部位的质量浓度均为500 g/L时,对金黄色葡萄球菌、大肠杆菌、绿脓杆菌的抑菌圈直径分别大于(17.62±0.22)、(25.21±2.09)和(12.82±0.30)mm,肉桂乙酸乙酯部位抑菌作用较弱,肉桂和根皮正丁醇部位和水部位对3种供试菌种均无抑制作用。     

小远志中酮类化学成分及生物活性研究

以小远志干燥根茎为原料,采用乙醇提取、硅胶柱层析、Sephadex LH-20、MCI-gel和半制备型HPLC分离等方法对小远志中酮类化学成分进行研究。从中分离得到18个酮类化合物,根据理化性质及ESI-MS、~1H NMR、~(13)C NMR等波谱数据,分别鉴定为:1,7-二羟基酮(1),3,6-二羟基-1,2,7,8-四甲氧基酮(2),1,7-二羟基-5,6-二甲氧基酮(3),1,5-二羟基-6,7-二甲氧基酮(4),6-羟基-1,7-二甲氧基酮(5),7-羟基-1-甲氧基酮(6),3,8-二羟基-1,2,4-三甲氧基酮(7),6,8-二羟基-1,2,3-三甲氧基酮(8),1,3,6-三羟基-2,7,8-三甲氧基酮(9),3-羟基-1,2,8-三甲氧基酮(10),1,3,7-三羟基酮(11),1,6-二羟基-2,3-二氧亚甲基-7,8-二甲氧基酮(12),1,7-二羟基-2,3-二甲氧基酮(13),1,6-二羟基-5,7-二甲氧基酮(14),3,7-二羟基-1,2-二甲氧基酮(15),3,7-二羟基-1,2,8-三甲氧基酮(16),1,2,3,7-四甲氧基酮(17),1,6-二羟基-3,5,7,8-四甲氧基酮(18),除化合物13外,其它化合物均为首次从该植物中分离得到。对其中分离所得量较多的化合物1~7进行了抗氧化及抗菌实验,发现化合物4和1有较好的抗氧化活性,对ABTS·的IC50值分别为12和13 mg/L;化合物3对金黄色葡萄球菌有一定的抑制作用,MIC值为217μmol/L。     

四川山姜的化学成分研究

采用正相硅胶和Sephalex LH-20凝胶色谱柱层析等分离方法对姜科山姜属植物四川山姜的乙酸乙酯部位的成分进行分离纯化,根据理化性质和波谱数据进行结构鉴定.分离得到了8个化合物,分别鉴定为3,5-二羟基-4′,7-二甲氧基黄酮(1)、4′,7-二羟基-5-甲氧基二氢黄酮(2)、4′,5,7-三羟基黄酮(3)、5,7-二羟基-4′甲氧基黄酮(4)、对香豆酸(5)、β-胡萝卜苷(6)、β-谷甾醇(7)和豆甾醇(8).化合物1～5为首次从该植物中获得.     

Antimicrobial and free radical scavenging activities of Teucrium montanum

The antimicrobial and free radical scavenging activities of petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts of Teucrium montanum were investigated. Ethyl acetate, chloroform and n-butanol extracts expressed a wide range of inhibiting activity against both Gram (+) and Gram (-) bacteria. n-Butanol extract possessed potent DPPH free radical scavenging 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).     

胆木叶提取物的抗氧化活性研究

以胆木叶为原料,通过不同极性溶剂依次萃取50%醇提取物,分别得到石油醚萃取物(PEE)、氯仿萃取物(CE)、乙酸乙酯萃取物(EAE)、正丁醇萃取物(BE)和水萃取物(WE),它们的收率依次为0.62%、3.90%、0.68%、1.78%和6.06%.采用过氧化氢体系、超氧阴离子(O-2·)体系、羟基自由基体系(·OH)和Oyaizu法,以Vc为阳性对照,进行5个不同萃取部分抗氧化活性的测定和比较.结果表明,5种萃取部分均具有一定的抗氧化活性,随着浓度的增加而提高;且在不同的自由基产生体系中,其抗氧化活性强弱不尽相同.在过氧化氢体系中,对H2O2的清除能力强弱顺序依次为Vc>BE>CE>EAE>PEE>WE;在超氧阴离子体系中,对O-2·抗氧化活性强弱顺序依次为Vc>EAE>BE>PEE>WE>CE,在羟基自由基体系中,对·OH抗氧化活性强弱顺序依次为Vc>BE>CE>EAE>PEE>WE;而其还原能力强弱顺序依次为 BE>EAE>WE>CE>PEE.     

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.     

Molluscicidal activity against Oncomelania hupensis of Ginkgo biloba

In search for molluscicidal active components, petroleum ether, ethyl acetate, ethanol, and water extracts from Ginkgo sarcotesta were evaluated against the snail Oncomelania hupensis. The bioassay-oriented showed that the activity concentrates in the petroleum ether extract (LD(50) 7.81 ppm). Ginkgolic acids, isolated from the petroleum ether extract, exhibited strong molluscicidal activity (LD(50) 1.49 ppm), gingkgolic acid C15:1 having the strongest molluscicidal activity.     

Cytotoxicity and antibacterial activity of extractives from Wedelia calendulacea

The cytotoxicity and antibacterial activity of petroleum ether, chloroform and methanol extracts of Wedelia calendulacea were assayed by brine shrimp lethality bioassay and standardized disk diffusion method against 19 bacterial strains. Three diterpenes isolated from the plant were also evaluated for in vitro antibacterial activities. The LC50 for the crude extracts against the brine shrimp nauplii were found to be 4.59 microg/ml, 7.99 microg/ml and 14.88 microg/ml, respectively, whereas the positive control, vincristine sulfate showed an LC50 of 0.58 microg/ml. Among the crude extracts and pure compounds tested, (-)-kaur-16-en-19-oic acid isolated from the chloroform extract showed the highest inhibitory activity against most of the bacterial strains with mean zone of inhibition of 10-21 mm at 200 microg/disc.     

Antibacterial activity of Eupatorium glandulosum leaves

Antibacterial screening of petroleum ether, chloroform, ethyl acetate, methanol and aqueous extracts of Eupatorium glandulosum leaves exhibited a broad spectrum of inhibitory activity against Gram (+) and Gram (-) pathogenic bacteria.     

Antimicrobial activity of crude extracts and pure compounds of Hypericum hircinum

The antimicrobial activity of the n-hexane (H) and chloroform (C) extracts, the methanol extract (M) and its ethyl acetate (E) and n-butanol (B) fractions, and six isolated constituents of the aerial parts of Hypericum hircinum was investigated using an agar diffusion method. The maximum activity was exhibited by the methanolic extract against Staphylococcus aureus, while all pure constituents showed no antimicrobial activity against the tested microorganisms.     

Antibacterial activity of Salacia beddomei

Leaves and stems of Salacia beddomei were extracted successively with petroleum ether, ethyl acetate and chloroform and tested for their antibacterial activity. Ethyl acetate extracts were found to be most effective against all the tested organisms.     

Antimicrobial activity of extracts of Clematis vitalba towards pathogenic yeast and yeast-like microorganisms

A broad activity against pathogenic yeast and yeast-like microorganisms was shown in crude extracts of young shoots of Clematis vitalba. MICs ranging from 1.4 to 12.3 microg/ml were observed. After fractionating with petroleum ether, ethyl acetate and methanol, antimycotic activity has been observed only in methanol fractions.