Abstract

Alkaloids are secondary metabolite compounds found in organisms, both on land and in the sea. These alkaloid compounds play a significant role in human life. The highest concentration of alkaloids is often discovered in marine sponges, which possess abundant alkaloid content. Consequently, research has been conducted to further explore the chemical content of these marine sponges, particularly their activity as antibacterial agents. The objective of this study is to isolate new alkaloid compounds from the <em>Aaptos sp</em>. marine sponge, determine their alkaloid structure, and evaluate their in vitro antibacterial activity. The initial phase of this research involves extracting the <em>Aaptos sp</em>. marine sponge using a mixture of dichloromethane and methanol in a 1:1 ratio. Subsequently, the methanol extract is partitioned using n-hexane to yield a concentrated extract. The methanol extract is then obtained and tested for antibacterial activity. The anticipated outcome of this study is the discovery of chemical compounds exhibiting antibacterial properties, potentially serving as primary compounds (lead compounds) for developing alternative antibacterial drug candidates. The obtained results exhibit inhibition zones of 9.700 ± 0.374 mm and 7.766 ± 0.694 mm against Gram-positive and Gram-negative bacteria, respectively, indicating the potential of this sponge’s methanol extract as an antibiotic.