Núcleo de Pesquisa em Ciências Exatas e Tecnológicas da Universidade de Franca , Franca, SP , Brasil.
Braz J Microbiol. 2012 Apr;43(2):793-9. doi: 10.1590/S1517-83822012000200045. Epub 2012 Jun 1.
This work describes the phytochemical study of the extracts from aerial parts of Tibouchina candolleana as well as the evaluation of the antimicrobial activity of extracts, isolated compounds, and semi-synthetic derivatives of ursolic acid against endodontic bacteria. HRGC analysis of the n-hexane extract of T. candolleana allowed identification of β-amyrin, α-amyrin, and β-sitosterol as major constituents. The triterpenes ursolic acid and oleanolic acid were isolated from the methylene chloride extract and identified. In addition, the flavonoids luteolin and genistein were isolated from the ethanol extract and identified. The antimicrobial activity was investigated via determination of the minimum inhibitory concentration (MIC) using the broth microdilution method. Amongst the isolated compounds, ursolic acid was the most effective against the selected endodontic bacteria. As for the semi-synthetic ursolic acid derivatives, only the methyl ester derivative potentiated the activity against Bacteroides fragilis.
本工作描述了对蒂布香茶菜地上部分提取物的植物化学研究，以及对提取物、分离化合物和熊果酸半合成衍生物的抗牙髓细菌的抗菌活性评估。对蒂布香茶菜的正己烷提取物进行 HRGC 分析，鉴定出 β-香树脂醇、α-香树脂醇和 β-谷甾醇为主要成分。从二氯甲烷提取物中分离出三萜熊果酸和齐墩果酸并进行了鉴定。此外，还从乙醇提取物中分离出黄酮类化合物木犀草素和染料木素并进行了鉴定。通过肉汤微量稀释法测定最小抑菌浓度（MIC）来研究抗菌活性。在所分离的化合物中，熊果酸对所选牙髓细菌的活性最强。对于熊果酸的半合成衍生物，只有甲酯衍生物增强了对脆弱拟杆菌的活性。
