Essential oil from Cymbopogon nardus was evaluated for activity against Trypanosoma brucei brucei BS221 (IC50 = 0.31 ± 0.03 μg/mL) and cytotoxic effect on normal kidney (Vero) cells (IC50 = >100 μg/mL). The crude essential oil was subjected to various chromatography techniques afforded active sub fractions with antitrypanosomal activity; F4 (IC50 = 0.61 ± 0.06 μg/mL), F6 (IC50= 0.73 ± 0.33 μg/mL), F7 (IC50 = 1.15 ± 0 μg/mL) and F8 (IC50 = 1.11 ± 0.01 μg/mL). These active fractions did not exhibit any toxic effects against Vero cell lines and the chemical profiles investigation indicated presence of α-and γ-eudesmol, elemol, α-cadinol and eugenol by GC/MS analysis.

Aims: The present study is aimed at taxonomic characterization and isolation of active compound MS01 from Streptomyces sp. FACC-A032 which exhibited strong antitrypanosomal activity (IC50 0.02 μg/mL). Methodology and results: Isolate FACC-A032 was characterized based on its cultural, morphological, physiological and genomic properties. Isolate FACC-A032 was tentatively identified as Streptomyces sp. Biochemical analysis of diaminopimelic acid (DAP) isomer of whole-cell hydrolysates further confirmed the isolate FACC-A032 that contained LL-DAP isomer as species belonging to the genus Streptomyces. The inoculum for submerged cultures of isolate FACCA032 was prepared from cultures on ISP2 agar. After eight days of growth at 28  2 °C and 200 rpm in fermentation medium M3, fermentation broth was extracted with butanol and the crude extracts (solvent layer) were separated and dried in vacuo. Further studies were carried out to isolate the active compound from the culture extracts of isolate FACCA032. Using bioassay-guided isolation, crude extract was partitioned based on different polarity. After which, the resulting elutes were tested for antitrypanosomal activity. The active fraction was analyzed with HPLC-DAD analysis. Based on the analysis, major peak in the active fraction was collected using HPLC preparative. Active compound MS01 was isolated and structure elucidated using NMR spectroscopy. Conclusion, significance and impact of study: Bioassay-guided isolation techniques used in this study had discovered an active antitrypanosomal compound, staurosporine, from Streptomyces sp. FACC-A032. This is the first discovery of staurosporine, a protein kinase inhibitor, from Malaysian soil actinobacteria Streptomyces sp. Therefore, the study demonstrated the potential of Malaysian soil actinobacteria as antitrypanosomal therapeutic agent.
Biological Assay ; Actinobacteria