SummaryThis paper reports on the vinca alkaloid produced by a novel Nigrospora sphaerica isolated from Catharanthus roseus. Through liquid chromatography–mass spectrometry (LCMS), only the crude mycelia extract of this fungus was positive for determination of vinblastine. This vinca alkaloid was then purified by using high‐performance liquid chromatography (HPLC) and tested for cytotoxicity activity using MTT assays. The breast cell line cancer (MDA‐MB 231) was treated with a purified vinblastine which was intracellulary produced by N. sphaerica. The purified vinblastine from extracted leaf of C. roseus was used as a standard comparison. A positive result with a value of half maximal inhibitory concentration (IC 50) of > 32 μg ml−1 was observed compared with standard (IC 50) of 350 μg ml−1 only. It showed that a vinblastine produced by N. sphaerica has a high cytotoxicity activity even though the concentration of vinblastine produced by this endophytic fungus was only 0.868 μg ml−1.

This paper reported on the various filamentous fungi strains that were isolated from a wild grown Catharanthus roseus. Based on the morphological characteristics and molecular technique through a Polymerase Chain Reaction and DNA sequencing method using internal transcribed spacer (ITS), these fungi had been identified as a Colletotrichum sp., Macrophomina phaseolina, Nigrospora sphaerica and Fusarium solani. The ultrastructures of spores and hyphae were observed under a Scanning Electron Microscope. The hydrolytic enzyme test showed that all strains were positive in secreting cellulase. Colletotrichum sp. and F. solani strains also gave a positive result for amylase while only F. solani was capable to secrete protease. These fungi were putatively classified as endophytic fungi since they produced extracellular enzymes that allow them to penetrate plant cell walls and colonize with symbiotic properties.

Four endophytic fungi have been tested for antioxidant properties using different assays; DPPH radicalscavenging activity, ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity (FCA). The test of polyphenolic content also has been done for both total phenolic content (TPC) and total flavonoid content (TFC). There was no result on the half maximal concentration (IC50) for both DPPH and FCA assays for all fungi. However, through FRAP assays the results were ranged from 0.336±0.01 to 0.477±0.11 mmol Fe 2+ /g extract where N. sphaerica had the highest result. This fungus also showed the highest results on TPC and TFC, which were 0.030±0.000 (mg GAE/g) and 0.038±0.001 (mg QE/g) respectively.