Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Chin J Integr Med. 2010 Aug;16(4):337-43. doi: 10.1007/s11655-010-0527-8. Epub 2010 Aug 10.
To evaluate the antimicrobial activity of the methanol extract from the stem bark of Drypetes tessmanniana, fractions (DTB1-5) as well as compounds [friedelin (2), 3,7-dioxofriedelane (3), 3,15-dioxofriedelane (4), 3beta- O-(E)-3,5-dihydroxycinnamoyl-11-oxo-olean-12-ene (6), and 3beta,6alpha-dihydroxylup-20(29)-ene (7).
Agar disc diffusion was used to determine the sensitivity of the above samples, whilst the microdilution method was used for the determination of the minimal inhibitory concentration (MIC) and the minimal microbicidal concentrations (MMC).
The diffusion test showed that the crude extract was able to prevent the growth of all tested organisms. All other samples showed selective activity. The inhibitory effect of the fraction DTB2 was noted on 63.7%, that of DTB1 and DBT3 on 54.6%, whilst DTB4 and DTB5 were active on 9.1% of the 11 tested organisms. The tested compounds prevented the growth of 81.8% of the tested microbial species for compounds 3 and 4, 36.7% for compound 6, and 18.2% for compound 7. The results of the MIC determinations indicated perceptible values for DTB and compound 4 on 81.8% of the tested organisms. For other samples, MICs were detected on 0-63.7%. The lowest MIC value (78.12 microg/mL) for the crude extract and fractions (DTB2) was observed on M. audouinii. The corresponding value for isolated compounds (156.25 microg/mL) was noted with compounds 3 on S. faecalis and 4 on M. audouinii audouinii. The results of the MMC determination suggested that the microbicidal effect of most of the tested samples on the studied microorganisms could be expected.
The methanol extract from the stem bark of Drypetes. tessmanniana (Euphorbiaceae) as well as some of the isolated compounds might be potential sources of new antimicrobial drugs.
评估从 Drypetes tessmanniana 茎皮的甲醇提取物、馏分（DTB1-5）以及化合物[friedelin（2）、3,7-二氧代friedelane（3）、3,15-二氧代friedelane（4）、3β-O-（E）-3,5-二羟基肉桂酰-11-氧代齐墩果-12-烯（6）和 3β,6α-二羟基羽扇豆-20（29）-烯（7）的抗菌活性。
琼脂扩散法用于测定上述样品的敏感性，而微量稀释法用于测定最小抑菌浓度（MIC）和最小杀菌浓度（MMC）。
扩散试验表明，粗提取物能够阻止所有测试生物的生长。其他所有样品均表现出选择性活性。DTB2 馏分的抑制作用在 63.7%的情况下得到证实，DTB1 和 DTB3 在 54.6%的情况下得到证实，而 DTB4 和 DTB5 在 11 种测试生物的 9.1%中具有活性。测试化合物 3 和 4 阻止了 81.8%的测试微生物种的生长，化合物 6 阻止了 36.7%的生长，化合物 7 阻止了 18.2%的生长。MIC 测定结果表明，DTB 和化合物 4 对 81.8%的测试生物具有明显的数值。对于其他样品，在 0-63.7%之间检测到 MIC。粗提取物和馏分（DTB2）对 M. audouinii 的最低 MIC 值（78.12μg/mL）。在 S. faecalis 和 M. audouinii audouinii 上，化合物 3 的相应值为 156.25μg/mL，化合物 4 的相应值为 156.25μg/mL。MMC 测定结果表明，大多数测试样品对研究微生物的杀菌效果是可以预期的。
从 Drypetes. tessmanniana（大戟科）茎皮中提取的甲醇提取物以及一些分离出的化合物可能是新的抗菌药物的潜在来源。
