New coumarins from the <i>n</i> -butanol part of <i>Prangos pabularia</i>

Chemical investigations of the <i>n</i>-butanol extract of the roots of <i>Prangos pabularia</i> were carried out using column chromatography, flash, semi-preparative HPLC, and chiral HPLC. Five unidentified compounds, including two prenylated coumarin glucosides, two prenylated furanocoumarin glucosides, and a benzofuran glucoside, together with twelve known compounds, were isolated from the <i>n</i>-butanol fraction of <i>P. pabularia</i> extract. The structures of these compounds were identified by HRMS, NMR, UV, ECD in combination with quantum chemical calculations, and comparison with the literature. The new compounds were named as yuganins C-G (1-5). Yuganin C (1) and yuganin D (2) are <i>C</i>-prenylated coumarin glucosides, yuganin E (3) is an 8-<i>O</i>-prenylated furanocoumarin glucoside, yuganin F (4) is a furanocoumarin 5-<i>O</i>-glucoside, and yuganin G (5) is a benzofuran glucoside. The isolated compounds were evaluated for their anti-vitiligo activity. All the individual isolated compounds showed anti-vitiligo effects. Compounds 10, 12, and 13 showed the highest melanin rate activation.