Biochemical Characterization and Bioactivity of Red Alga, Ceratodictyon spongiosum (Zanardini) from Goso-on, Carmen, Agusan Del Norte, Philippines

Abstract

Rhodophyta, present in marine and freshwater habitats, are the most varied group of seaweeds and an essential source of biochemical compounds. This study aimed to analyze the bioactive properties and composition of Rhodophyta Ceratodictyon spongiosum (Zanardini). The species was subjected to FTIR, antibacterial, cytotoxic, and proximate analyses. The proximate composition of ethanolic extract C. Spongiosum included 10.28±0.04% moisture, 41.09±0.09% ash, 36.00±0.38% crude protein, 2.63±0.02% crude fat, 1.21±0.02% crude fiber, and 0.65±0.02% total sugar. The FTIR spectrum subsequently reveals the presence of numerous functional groups, including alcohol, amine salt, carboxylic acid, alkene, amine, alkane, conjugated alkene, ester, primary amine, aromatic group, ether, and oxy. The species also demonstrated highly potent antibacterial activity against S. aureus (24.67±0.58) and E. coli (22.67±0.58). Moreover, after 6 hours in BSLT, the extracted sample resulted in a 3% mortality rate at just 100 ppm, yielding an LC₅₀ of 928.86 ppm. Nevertheless, at 24 hours, the extracts sample produced high percentage mortality of 45.56 percent, 96.6 percent, and 100 percent at 1, 10, and 100 ppm, respectively, and acquired an LC₅₀ of 0.96 ppm, which was extremely poisonous to brine shrimp nauplii. Additional research on Ceratodictyon spongiosum in Mindanao is recommended because it contains biological components that might lead to the discovery of novel medications and food products for industrial and medicinal uses.