Secondary metabolites of endophytic fungii isolated from the stem bark of Sungkai (Peronema canescens Jack.)

Abstract

Infectious diseases are a global challenge today. One preventive measure is to maintain and improve humans’ immunity. Many people consume sungkai, a medicinal plant that is believed to cut down the exposure of severe covid-19 because it is related to antioxidant and antibacterial activity. This research investigated the antioxidant and antimicrobe agents of fungal endophyte extracts from the stem bark of sungkai. Endophytic fungal was isolated from the fresh tissue of the stem bark of sungkai and identified morphologically. The antioxidant of the endophytic fungi extract was tested with the DPPH, and antibacterial agent was tested by using the paper disc diffusion method. Molecular identification of endophytic fungi was done to extract that showed the most potential antioxidant and antibacterial activity. The pure compounds were isolated by chromatographic techniques. Structural determinations of the compounds were accomplished using a spectroscopic method, comprising 1D and 2D NMR. Twenty isolates of fungal endophyte were found residing in the stem bark of sungkai, specifically RB1-RB20. Isolates RB4 and RB6 showed the most potential antioxidant and antibacterial activity and were identified molecularly. The results of molecular identification showed that RB4 and RB6 were Curvularia intermedia and Colletotrichum cliviicola. Based on the spectroscopic analysis, the compounds identified from the two fungi were the different compound, specifically 3-hydroxy-4(hydroxy(4-hydroxyphenyl)methyl)-ɣ-butyrolactone (1) and 5-hydroxy-4-(hydroxymethyl)-2H-pyran-2-on (2). Compound 1 and 2 showed antibacterial and antioxidant in strong to moderate. These compounds and the endophytic fungi extract can be used as a new ingredient for medicine because it has antioxidant and antibacterial activity with further research.