Abstract
ABSTRACT
Two new 3,4‐
seco
‐ergostane‐type steroidal saponins (
1
and
2
) were isolated from the fermentation products of the fungus
Xylaria necrophora
SZSS1‐2‐2, together with four known compounds: 2‐hexylidene‐3‐methylsuccinic acid (
3
), xylcarpin C (
4
), (24
R
)‐22,23‐dihydroxy‐ergosta‐4,6,8(14)‐trien‐3‐one 23‐
β
‐D‐glucopyranoside (
5
), and 5‐carboxymellein (
6
). The structures and absolute configurations of the new compounds were elucidated by comprehensive spectroscopic analyses, electronic circular dichroism (ECD), and GIAO
1
3
C NMR computational methods, and chemical hydrolysis followed by derivatization to determine the D‑mannose configuration of the sugar moiety. All isolated compounds (
1–6
) were evaluated for their biological activities. Only compound
5
showed selective inhibitory activity, inhibiting BV2 microglial cells with an IC
50
value of 17.10 ± 4.18 µM. Additionally, none of the compounds exhibited antimicrobial activity against the tested microorganisms.