Chemical Composition of Spheciospongia Aff. Mastoidea Sponge from the Red Sea and Uses of Its Polysaccharides in the Biosynthesis of Silver Nanoparticles with Antimicrobial and Anticancer Activity

Here, we studied the chemical composition of Spheciospongia aff. Mastoidea sponge collected from the Red Sea. The chemical profile of the n-hexane fraction was studied using GC-MS and revealed the presence of 11 compounds. The most abundant compounds were hexadecanoic acid methyl ester (49.93%), 9-octadecenoic acid methyl ester (22.13%), and other minor products. Additionally, three compounds were isolated from the ethyl acetate and n-butanol fractions of Spheciospongia aff. Mastoidea and identified as β-sitosterol, cholesterol, and allantoin, respectively. The chemical structures of the isolated compounds were identified by different spectroscopic methods, including mass and NMR spectroscopy. Crude polysaccharides (CPs) were also extracted from the aqueous extract of the collected sponge, and HPLC-RID characterized their monosaccharides. We developed a biological method for synthesizing silver nanoparticles using the reducing power of CPs. The biosynthesized AgNPs were confirmed using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Zeta potential. The nanoparticles had a spherical shape in the TEM image, with an average size of 18.21 to 36.92 nm and zeta potential values of -27.3 mV. The biosynthesized AgNPs-CPs showed enhanced antibacterial activity against several pathogens compared to CPs with no remarkable activity. Moreover, the AgNPs-CPs exhibited a cytotoxic effect against breast adenocarcinoma cell lines (MCF-7), liver cancer cell lines (HepG-2), prostate cancer cell lines (PC-3), adenocarcinomas alveolar basal epithelial cells (A549), and colorectal carcinoma cell lines (HCT116) with IC₅₀ values of 5.60, 13.0, 2.62, 46.3, and 29.20 µg/ml, respectively.