Abstract

3β-hydroxyllup-20(29)-en-28-oic acid (Betulinic acid) a Pentacyclic lupane triterpene known for anti-HIV activity and cytotoxic activity against various malignant versus nonmalignant cancer cell lines, was isolated from malaleuca bracteata. The structure was elucidated on the basis of spectroscopy analysis, including 2D-NMR correlation spectroscopy (COSY), nuclear overhauser enhancement spectroscopy (NOESY), heteronuclear multiple bond correlation (HMBC) and heteronuclear single quantum correlation (HSQC) experiments. The inhibitory zone (mm) ranges from 20 ± 0.02 to 30 ± 0.01 against the test organisms. Trichophyton tonsurans was the most sensitive organism (30 ± 0.01) which was observed to be greater than the standard drugs Fluoconazole (14 ± 0.90), Nystatin (17 ± 0.03) and Fulcin (23 ± 0.50) used as positive control. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) results indicated that a concentration of 0.625 and 2.5 mg/ml inhibited and completely kill Candida guielemondi, Candida stelletoidea, Candida parapsilosis, Candida pseudotropicalis, T. tonsurans and Microsporum canis except T. tonsurans which was kill at 1.25 mg/ml. While the rest of the organisms were inhibited and kill by a concentration of 1.25 and 2.5 mg/ml respectively, the results shows that the compound have great potential as antifungal drug.

Key words: Betulinic acid, pentacyclic triterpene, antifungal, nuclear magnetic resonance spectroscopy.