Antioxidant and Antibacterial Activity of Endophytic Fungi Isolated from The Leaves of Sungkai (Peronema canescens)

Abstract

Sungkai (Peronema canescens) is a medicinal plant widely used in Indonesia. Its leaves are believed to have the potential to treat fever and boost the immune system. This study investigated the antioxidant and antibacterial activity of endophytic fungi extracts obtained from Sungkai leaves. This will provide basic information for developing the potential of natural ingredients as antioxidants and antibacterials. Endophytic fungi residing in Sungkai leaves were identified morphologically. The antioxidant test was completed using DPPH, while the antibacterial activity was tested using the paper disk diffusion method. Most potential endophytic fungal isolates were identified through molecular identification, and the isolation of a bioactive compound was achieved using column chromatography. The structure of the compound was determined using 1D and 2D NMR spectroscopy methods. Four endophytic fungi isolates were observed in the Sungkai leaves (code RND1–RND4). RND3 demonstrated very strong antioxidant activity (IC50 < 20 µg/mL) and strong antibacterial activity. Based on the molecular test, RND3 was identified as Aspergillus niger. The pure compound isolated from RND3 revealed weak and strong antioxidant (IC50 > 500 µg/mL) and antibacterial (MIC ≤ 64 µg/mL) properties, respectively. Spectroscopic analysis showed that compound 1 was 3-benzyl-2,6-dihydroxy-1,4,11,13-tetramethyl-5- methylene-12,15-dioxo-14-oxabicycloheptadeca-8,16-diene-7-carboxylic acid. Through further research, this study can be used as a basis for the development of compounds as raw materials for drugs.

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

“…contains 2'-deoxyribolactone, hexylitaconic acid, and ergosterol, while Colletotrichum sp. contains 3-methyl 1-butanol [isopentyl alcohol), 4-amino-1-pentanol, p-Hydroxyphenylacetic acid, Pterin-6-carboxylic acid, and d-alaninol [52][53][54][55][56]. The metabolites constituent produced by the two fungal endophytes belong to the phenolic, pyran, flavonoid, sesquiterpene, and naphthalene groups, compounds of which have antioxidant and antibacterial activities [57][58][59][60].…”

Synergistic Antibacterial Effects of Combined Phytochemicals of Endophytic Fungi Extracts and Its Pure Compounds Isolated from Sungkai (Peronema canescens) Leaves

“…The MIC value was used to examine the antibacterial efficacy of each endophytic fungus ethyl acetate extract (Table 3). The MIC value was also determined for a pure compound that had been previously isolated, namely 4-hydroxybenzoic acid (C1) isolated from Trichoderma asperellum [27]; 3-methyl-3,4-dihydro-1Hisochromene-1,8(7H)-dione (C2) and 3-hydroxy-4(hydroxy(4-hydroxyphenyl)methyl)-ɣ-butyrolactone (C3) isolated from Pythium periplocum [25]; 3-(2,6dihydroxyphenyl)-2-hydroxyacrylic acid (C4) isolated from Penicillium oxalicum [28]; and 3-benzyl-2,6-dihydroxy-1,4,11,13-tetramethyl-5-methylene-12,15-dioxo-14oxabicycloheptadeca-8,16-diene-7-carbo-xylic acid (C5) isolated from Aspergillus niger [29] listed in Table 3.…”