Antifungal Activity of Extracts, Fractions, and Constituents from Coccoloba cowellii Leaves

Abstract

Coccoloba cowellii Britton (Polygonaceae, order Caryophyllales) is an endemic and critically endangered plant species that only grows in the municipality of Camagüey, a province of Cuba. A preliminary investigation of its total methanolic extract led to the discovery of promising antifungal activity. In this study, a bioassay-guided fractionation allowed the isolation of quercetin and four methoxyflavonoids: 3-O-methylquercetin, myricetin 3,3′,4′-trimethyl ether, 6-methoxymyricetin 3,4′-dimethyl ether, and 6-methoxymyricetin 3,3′,4′-trimethyl ether. The leaf extract, fractions, and compounds were tested against various fungi and showed strong in vitro antifungal activity against Cryptococcus neoformans and various Candida spp. with no cytotoxicity (CC50 > 64.0 µg/mL) on MRC-5 SV2 cells, determined by a resazurin assay. A Candida albicans SC5314 antibiofilm assay indicated that the antifungal activity of C. cowellii extracts and constituents is mainly targeted to planktonic cells. The total methanolic extract showed higher and broader activity compared with the fractions and mixture of compounds.

Helichrysum stoechas (L.) Moench reduces body weight gain and modulates mood disorders via inhibition of silent information regulator 1 (SIRT1) by arzanol

“…Compound 29 with a [M-H] À = 359 showed two product ions at m/z 344 and m/z 329, corresponding to two subsequent losses of a methyl group. This fragmentation pattern was described in the literature for two compounds, which were tentatively identified as myricetin-3,3 0 ,4 0 -trimethyl-ether and methoxyquercetin-dimethyl-ether (Méndez et al, 2021). F I G U R E 1 HPLC-UV chromatogram of the Helichrysum stoechas extract (HSE), acquired at 280 nm.…”