温莪术内生真菌的分离及其抗菌活性的初步研究

 目的研究温莪术内生真菌的种群组成及其代谢产物抗菌活性。方法采用内生菌常规分离法对健康温莪术植株体内的内生真菌进行了分离鉴定。以大肠杆菌、金黄色葡萄球菌、链球菌、沙门氏菌、巴氏杆菌为测试菌种,对温莪术根、茎、叶中分离的56株内生真菌进行抗菌活性筛选。结果经初步鉴定,这些内生真菌为5目、6科、24属;抑菌实验表明,56株内生真菌中有39株对5种测试菌均有不同程度的抑制作用。结论温莪术植物含有丰富多样的内生真菌,且多数内生真菌都表现为较高的抑菌活性。     

乌桕根皮水提物抗菌活性的初步研究

目的探讨乌桕根皮水提物的抗菌活性以及不同温度条件下的提取物抗菌活性差异。方法采集乌桕根皮,在3种不同温度(60,80,100℃)下用水回流提取,提取物浓缩后进行抗菌测试,受试菌:枯草杆菌、大肠杆菌、金黄色葡萄球菌、绿脓杆菌和志贺氏杆菌。结果水提物对大肠杆菌和志贺氏杆菌具有抑制作用,对枯草杆菌、金黄色葡萄球菌和绿脓杆菌没有活性;不同温度下的提取物对大肠杆菌和志贺氏杆菌的影响较大,提取温度为100℃时,提取物对这两种细菌的抑制作用最强,抑菌圈直径分别为(9.67±1.32)mm和(11.67±1.00)mm。结论乌桕根皮在湖南和广西民间治疗由大肠杆菌引起的腹泻和志贺氏杆菌引起的痢疾确有很好的疗效。     

莪术油与药渣残油的化学成分和抗菌活性比较

目的:研究莪术油与药渣残油的化学成分和抗菌活性的差别,为充分利用温莪术药渣提供科学依据。方法:采用水蒸气提取法提取莪术油和药渣残油,采用气质联用方法分别对莪术油和药渣残油的化学成分进行研究,采用微量稀释法对莪术油和药渣残油进行了抗菌活性测试。结果:从莪术油中得到78个化合物,鉴定出29个,占总成分的86.68%;从药渣残油中得到78个化合物,鉴定出31个,占总成分的70.83%。温莪术油对大肠埃希菌和金黄色葡萄球菌有较好的活性,MIC值均为50.9 mg·L-1;药渣残油对四联球菌,大肠杆菌和金黄色葡萄球菌有较好的活性,MIC值均为44.4 mg·L-1。结论:对莪术油和药渣残油进行化学成分和抗菌活性对比,化学成分分析表明它们的主要化学成分类似,含量较高的成分有榄香烯、吉马酮、莪术烯,莪术二酮、新莪术二酮。抗菌实验表明药渣残油抗菌活性总体上比莪术油的抗菌活性强。首次对药渣进行残油提取以及抗菌活性测试,为温莪术药渣的综合利用提供科学依据。     

广东紫珠挥发油化学成分的GC-MS分析及体外抗菌活性

目的:分离和分析广东紫珠挥发油的化学成分,并考察其体外抗菌活性。方法:采用水蒸气蒸馏法提取广东紫珠挥发油,应用气质联用(GC-MS)法分析挥发油的化学成分,结合计算机检索技术对分离的化合物进行鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果:鉴定了38个化合物,占总离子流图峰面积的76.01%。广东紫珠挥发油对金黄色葡萄球菌、大肠杆菌和白色念珠菌显示出不同抗菌活性。结论:广东紫珠挥发油的主要化学成分是萜类化合物(59.25%),对金黄色葡萄球菌、大肠杆菌和白色念珠菌显示出不同的抗菌活性。     

清热散结胶囊体外和体内抗菌活性研究

目的 研究清热散结胶囊体外和体内抗菌活性。方法 采用微量肉汤稀释法进行体外抗菌实验，测定清热散结胶囊对一系列常见菌株，包括耐药菌在内的抑菌活性。评价清热散结胶囊对金黄色葡萄球菌和大肠杆菌引起小鼠感染的体内抗菌活性。探究清热散结胶囊抗菌有效成分对热、紫外光的稳定性。采用棋盘法评价清热散结胶囊与临床常用抗生素的联合用药效果。结果 清热散结胶囊具有广谱抗菌活性，对所筛菌株如金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、变异链球菌、粪肠球菌、铜绿假单胞菌表现出明显的活性抑制，最小抑菌浓度(MIC)为20 mg/mL或40 mg/mL。体内抗菌实验结果显示，中、高剂量清热散结胶囊(10、20 g/kg)可提高小鼠感染金黄色葡萄球菌和大肠杆菌的存活率(P<0.05,P<0.01)。稳定性实验结果显示，清热散结胶囊的抗菌有效成分具有很好的热稳定性，经50℃至121℃处理30 min后，抑菌MIC没有变化；紫外光照射30、60 min后，清热散结胶囊的抗菌活性亦没有变化，说明其抗菌活性成分对紫外光稳定。联合用药实验结果显示，清热散结胶囊与青霉素、氯霉素或者庆大霉素联合用药时具有协同作用。结论 清...     

4种单糖苯丙素苷类化合物的体外抗氧化作用及抑菌活性的研究

目的 以合成出经熔点、IR、1HNMR确证的4种单糖苯丙素苷类化合物对DPPH自由基的抗氧化效果和对大肠杆菌和金黄色葡萄糖球菌的抑菌活性的研究.方法 利用单糖苯丙素苷与DPPH单电子配对使其颜色逐渐消失,褪色程度与其接受的电子呈定量关系测定其抗氧化活性以及通过对大肠杆菌和金黄色葡萄糖球菌的抑菌圈大小来测定其抑菌活性强弱.结果 表明这4种单糖苯丙素苷类化合物都不同程度的表现出一定的抗氧化效果和抑菌活性.结论 4种单糖苯丙素苷类化合物都有一定的抗氧化效果和抑菌活性,为苯丙素苷活性的研究提供一些有意义的理论依据.     

泥螺脂溶性提取物抑菌活性研究

目的:筛选泥螺中的脂溶性抗菌活性物质,为泥螺的综合利用提供理论依据。方法:采用乙醇浸泡泥螺,氯仿对其进行分离提取,并以大肠杆菌作为指示菌对脂溶性提取物进行抑菌效果检测,测定其抗菌效果和理化特性。结果:经过分离得到含有泥螺脂溶性提取物的粗提液,粗提液抑菌效果明显,其抑菌活性表现出较好的热稳定性;粗提液在弱酸性(pH=5～6)条件下抑菌活性最好;冻融次数的增加对粗提液抑菌活性影响不大。结论:成功提取到泥螺脂溶性提取物,其在体外具有抗菌活性。     

网脉橐吾不同萃取部位抗菌活性研究

目的:研究网脉橐吾不同萃取部位的抗菌活性。方法:采用牛津杯琼脂扩散法和OD值法测定网脉橐吾不同萃取部位抗金黄色葡萄球菌、大肠杆菌、绿脓杆菌和沙门氏菌的活性。结果:石油醚部位对金黄色葡萄球菌和大肠杆菌的抑制效果比较明显,氯仿部位对4种试验菌都有抑制效果,且对大肠杆菌的抑制作用强于对其它3种细菌抑制作用,乙酸乙酯部位对绿脓杆菌的抑制效果比较明显,正丁醇部位的抗菌作用较为明显。萃余液部位仅对金黄色葡萄球菌有较弱的抑制作用。结论:网脉橐吾萃取液有较为明显的抗菌作用。     

10种中药的不同制剂对常见致病菌体外抗菌活性研究

目的:观察10种中药的不同制剂对金黄色葡萄球菌、表皮葡萄球菌、大肠杆菌、伤寒杆菌、绿脓杆菌的体外抗菌活性。方法:液体药基混合法,微量稀释法。结果:黄连对常见致病菌显示较强的抑制作用,黄芩次之。中药酊剂抗菌活性强于煎剂;联合用药以酊剂混合液与西药联合杀菌作用最强。结论:单味药中以黄连抗菌活性最强,不同制剂中以酊剂抗菌活性最强。     

25种黔产中药材提取物体外抑菌活性的筛选

目的:选取25种黔地中药材,研究其70%乙醇提取物对临床常见致病菌的体外抑菌活性。方法:中药粗粉用70%乙醇回流提取,通过纸锭琼脂扩散法测定提取物的抑菌圈,微量倍比稀释法测定最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果:25种黔产中药材醇提物中,有15种中药材对金黄色葡萄球菌和大肠杆菌均表现出不同程度的抑菌效果。其中,黄连、夏枯草、大黄、鱼腥草、金钱草等5种中药材对两种病原菌的抗菌活性较为突出,抑菌圈d≥20 mm;对两种病原菌的最低抑菌浓度范围在7.82~31.25 mg/mL之间;对两种病原菌的最低杀菌浓度范围在15.625~62.50 mg/mL之间。结论:首次筛选出的5种抗菌活性较强的黔产中药材,可为抗耐药性的中药抑菌剂和抑菌日化产品的开发提供一定的科学依据。     

苦苣苔科药用植物体外抗菌活性的研究

目的：选用体外抗菌试验对苦苣苔科7属14种常用药用植物进行抗菌活性初筛研究。方法：首先采用琼脂打孔法测定这些药材对细菌固有的敏感性,对菌株敏感的药材再用试管二倍稀释法测定最小押菌浓度（MIC）,以此判断其抗菌活性的强弱、结果：大部分药用植物对受试的金黄色葡萄球菌部有较强的抑制作用,牛耳朵对痢疾杆菌和大肠杆菌都有较强的抑制作用．结论：这些植物的抗菌活性与其传统疗效“活血化瘀,清热解毒”有较好的相关性。     

Evaluation of the antimicrobial potential of medicinal plants from the Ivory Coast

A total of 148 crude ethanol extracts from 115 plant species were tested in vitro against Gram-negative strains (Escherichia coli, Pseudomonas aeruginosa) and the Gram-positive Staphylococcus aureus and Enterococcus faecalis. Moreover, they were submitted to antifungal assays against Candida albicans and Cladosporium cucumerinum, a human and a plant pathogenic microorganism, respectively, known to be good indicators of antifungal activity. No activity was detected against the Gram-negative bacteria, while 14.8% and 10.8% of the extracts showed Gram-positive bactericidal or bacteriostatic effects on S. aureus and E. faecalis, respectively. An antifungal activity was observed with 15 extracts (10.1%). Two species were particularly active against the fungi: Dioscorea minutiflora and Erythrina vogelii. The young tubers of D. minutiflora contain metabolites with a specific effect on fungi and were not active against the bacteria. On the other hand, E. vogelii was highly effective against the Gram-positive bacteria and the fungi.     

In vitro bactericidal activity of diterpenoids isolated from Aframomum melegueta K.Schum against strains of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus

Ethnopharmacological relevance

The ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity.

Materials and methods

To substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against Escherichia coli K12; acetone extract and the fractions of acetone extracts were tested against Listeria monocytogenes. Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms.

Results

Four known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli, L. monocytogenes, methicillin resistant Staphylococus aureus (MRSA) and S. aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using nuclear magnetic resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed.

Conclusion

The results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.     

Antimicrobial and anti-inflammatory activity of four known and one new triterpenoid from Combretum imberbe (Combretaceae)

Combretum imberbe is used widely in Africa inter alia for treating bacterial infections. In addition to four known triterpenoids, 1alpha,3beta-dihydroxy-12-oleanen-29-oic (1), 1-hydroxy-12-olean-30-oic acid (2), 3,30-dihydroxyl-12-oleanen-22-one (3), and 1,3,24-trihydroxyl-12-olean-29-oic acid (4), a new pentacyclic triterpenoid (1alpha,23-dihydroxy-12-oleanen-29-oic acid-3beta-O-2,4-di-acetyl-L-rhamnopyranoside) 5 has been isolated through a bioassay-guided procedure from the leaves of Combretum imberbe. The structures of the compounds were elucidated on the basis of 1D and 2D NMR experiments, as well as mass spectrometric data. All compounds isolated had moderate (62 microg/ml) to strong (16 microg/ml) antibacterial activity (MIC values) against Staphylococcus aureus and Escherichia coli, with 1 and 5 being most active. Compounds 1 and 5 also showed very strong inhibition of 3alpha-hydroxysteroid dehydrogenase with an IC(50) of 0.3 microg/ml. Compound 5 indicated a moderate anti-proliferative (GI(50)=16.5 and 13.2 microg/ml) and cytotoxic activity (CC(50)=17.6 micro/ml) against K-562, L-929 and HeLa cell lines, respectively. The results of this study give credence to the ethnomedicinal use of Combretum imberbe and expand our knowledge on the biological activity of its metabolites.     

青连翘中的一个新咖啡酸苯乙醇苷

目的：研究青连翘的化学成分。方法：采用硅胶、HPLC等多种柱色谱分离手段,运用NMR和MS等波谱技术鉴定化合物的结构。并且通过体外平板法测试了所有化合物对8种菌株的抑菌活性。结果：从青连翘中分离并鉴定了5个化合物：phillygenin（1）,（＋）-isolariciresinol（2）,phillyrin（3）,forsythiaside（4）and lianqiaoxinsideA（5）。结论：连翘新苷A（5,3,4-二羟基-β-苯乙基-O-α-L-鼠李吡喃糖基-（1→6）-3-O-咖啡酰基-β-D-葡萄吡喃糖苷）为新化合物,咖啡酸苯乙醇苷类为连翘中的主要抑菌成分。     

杜仲叶桃叶珊瑚苷的酶法提取及其抑菌活性

目的:研究杜仲叶桃叶珊瑚苷的酶法提取工艺及其抑菌活性。方法:采用纤维素酶法,以桃叶珊瑚苷提取率为指标,优选最佳提取条件,并对其抑菌效果进行研究。结果:杜仲叶桃叶珊瑚苷的最佳提取工艺为:料液比1∶12,酶解pH 6.0,酶用量0.4%,酶解温度50℃,酶解时间50 min,溶出量可达17.892 mg/g。桃叶珊瑚苷提取液对大肠杆菌和金黄色葡萄球菌的抑菌作用较强,对金黄色葡萄球菌的MIC为4.832 mg/mL,对大肠杆菌的MIC为9.664 mg/mL,但对肺炎链球菌和MG溶血性链球菌的抑菌作用不明显,MIC均为28.946 mg/mL。结论:该提取工艺合理可行,提取率高,提取得到的桃叶珊瑚苷具有一定的抑菌作用。     

Antibacterial activity and in vitro anti-tumor activity of the extract of the larvae of the housefly (Musca domestica)

One of the significant characteristics of traditional Chinese medicine is the use of insects, other terrestrial arthropods and their products as drugs. In the present work, the extract of housefly (Musca domestica) larvae was studied by an agar well diffusion assay and minimum bactericidal concentration (MBC) determination for detection of antimicrobial activity and by MTT assay method to test its in vitro anti-tumor activity. In our studies, the extract inhibited six tested bacterial pathogens and Escherichia coli Jm109, a gene-modified strain resistant to ampicillin with the MBCs ranging from 200 to 1600 microg/ml, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The extract showed high in vitro anti-tumor activity against human colon cancer cell line CT26 with the IRs ranging from 62 to 89%. The extract of housefly larvae inoculated with Shigella dysenteriae 51302 exhibited higher antibacterial activity and in vitro anti-tumor activity than that of native larvae, which may indicate the same principle involved in the use of Bombyx mori larvae infected with silk moth fungus Beauveria bassiana and Hepialis larvae infected with Cordiceps fungus in the traditional Chinese medicine. Both extracts did not show any coagulation activity and haemolysis activity against rabbit erythrocytes at 500 and 1000 microg/ml. The results support its use in the traditional Chinese medicine, and warrant the further identification of the active molecule in the housefly larvae.     

Antimicrobial activity of 20 plants used in folkloric medicine in the Palestinian area

Ethanolic and aqueous extracts of 20 Palestinian plant species used in folk medicine were investigated for their antimicrobial activities against five bacterial species (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa) and one yeast (Candida albicans). The plants showed 90% of antimicrobial activity, with significant difference in activity between the different plants. The most antimicrobially active plants were Phagnalon rupestre and Micromeria nervosa, whereas, the least active plant was Ziziphus spina-christi. Only ten of the tested plant extracts were active against C. albicans, with the most active from M. nervosa and Inula viscosa and the least active from Ruscus aculeatus. Of all extracts the ethanolic extract of M. nervosa was the most active, whereas, the aqueous extract of Phagnalon rupestre was the most active of all aqueous extracts tested. The ethanolic extracts (70%) showed activity against both Gram positive and negative bacteria and 40% of these extracts showed anticandidal activity, whereas, 50% of the aqueous extracts showed antibacterial activity and 20% of these extracts showed anticandidal activity.     

Bioactive secolignans from Peperomia dindygulensis

Thirteen secolignans, including eight new ones (1-8), were isolated from the EtOAc extract of Peperomia dindygulensis. The structures were mainly elucidated by 1D and 2D NMR and MS experiments, the relative configurations were determined by NOE correlations, and the absolute configurations were established by the optical rotations and CD spectra. Cytotoxicity and MDR (multidrug resistance) reversal activity of the isolated compounds were examined. Compounds 6 and 7, peperomins B (10) and E (12), showed moderate to strong growth inhibitory activity against a malignant lung tumor cell (VA-13) with IC(50) values of 15.2, 13.5, 13.9, and 1.93 microM, respectively, and also inhibited the growth of a normal lung fibroblast cell (WI-38) at the same levels. Compound 7 and peperomin E (12) exhibited inhibitory activity against a liver tumor cell (HepG2) with IC(50) values of 22.3 and 12.1 microM. Compounds 5 and 7 and peperomins A, B, C, and E (9-12) enhanced calcein accumulation in MDR 2780 cells at 25 microg/mL. Compounds 2, 3, 7, and peperomin E (12) showed inhibitory activity on induction of the intercellular adhesion molecule-1 (ICAM-1).     

紫金砂体外抗菌活性的研究

目的紫金砂提取物及其提取部位抗菌活性的研究。方法95%乙醇提取,系统溶剂萃取分离得到5个部位,采用纸片扩散法对提取物及提取部位进行体外抗菌活性研究。结果紫金砂提取物对金黄色葡萄球菌、大肠杆菌具有抑制作用,氯仿提取部位对大肠杆菌、枯草芽胞杆菌具有抑制作用,正丁醇提取部位对大肠杆菌、绿脓杆菌具有抑制作用。结论紫金砂提取物及提取部位具有抗菌活性。