Secondary Metabolites of Isis hippuris: In vitro and In silico Studies on Antimicrobial Potential

Isis hippuris is a marine species and is abundant in Southeast Sulawesi. However, studies on its potential, particularly for medicinal development, are still limited. This research aims to explore the chemical contents and biological activities of I. hippuris from the waters of Bukori Island. Ethylacetate extract of I. hippuris (EAE) was fractionated by vacuum liquid chromatography (VLC) and analyzed through phytochemical screening and LC-MS/MS. The antimicrobial potential was evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans using the microdilution method and in silico analysis. The results showed that fractionation of EAE produced five fractions (A–E). Fraction E showed the highest antibacterial activity against S. aureus and E. coli, with MIC values of 2 μg/mL, thus categorized as susceptible. At the same time, Fractions C and E exhibited the highest antifungal activity against C. albicans, with MICvalues of 4 μg/mL, thus categorized as susceptible. Additionally, 3 out of 12 major compounds in Fraction E and 14 of 21 major compounds in Fraction C were identified. In silico studies predicted that periplocoside M and 25(S)-ruscogenin have the highest affinity for S. aureus, saurufuran B and siraitic acid E for E. coli, and abrusoside A and periplocoside M for C. albicans, targeting β- ketoacyl-ACP synthase, tyrosyl-tRNA synthetase, and sterol-14α-demethylase, respectively. In conclusion, I. hippuris from Southeast Sulawesi shows promising potential as an antibiotic agent