Polyketides from a marine medicinal brown alga-derived fungal strain Hypomontagnella monticulosa SC1047

In this study, a marine medicinal brown alga Sargassum cristaefolium-derived fungal strain Hypomontagnella monticulosa SC1047 was isolated and identified. The extracts from liquid-fermented products of the fungal strain were subjected to column chromatography, which yielded ten purified compounds. Their gross structures were characterized by spectroscopic analysis, and the absolute configurations were further established through modified Mosher's method and/or electronic circular dichroism spectroscopy. This analysis led to identification of six previously undescribed compounds, namely hypoketides A-F (1-6), along with four known compounds 7-10. All the isolates were examined for anti-inflammatory and anti-angiogenic properties. Of the tested compounds, compounds 2 and 7 could moderately inhibit nitric oxide production in lipopolysaccharide-activated BV-2 microglial cells with IC₅₀ values of 4.9 ± 0.3 and 8.9 ± 0.1 μM compared to that of curcumin (IC₅₀ = 2.7 ± 0.3 μM). Compounds 1, 2, and 7 exhibited moderate to slight inhibitory effects on the growth of human endothelial progenitor cells with IC₅₀ values ranging from 21.6 ± 0.6 to 63.8 ± 1.8 μM compared to that of sorafenib (IC₅₀ = 4.8 ± 0.5 μM).