Altersteroids A-D, 9,11-Secosteroid-Derived γ-Lactones from an Alternaria sp.
Peinan FuYang ZhangChenyin WangShuyi SiXingzhong LiuYongsheng ChePublished in: Journal of natural products (2023)
Altersteroids A-D ( 1 - 4 ), four new 9,11-secosteroid-derived γ-lactones, were isolated from cultures of the ascomycete fungus Alternaria sp. Their structures were elucidated primarily by NMR experiments. The absolute configuration of 1 was established by X-ray crystallographic analysis of its di- p -nitrobenzenesulfonate 1a using Cu Kα radiation, whereas those for 2 - 4 were assigned by quantum-chemical calculations. Compounds 1 - 4 incorporate a γ-lactone moiety fused to the steroid D ring at C-13/C-14. Compound 3 showed moderate cytotoxicity toward four tumor cell lines and induced an apoptotic process in A549 cells. Notably, compound 3 showed equipotent activity against the cisplatin-sensitive MB49 and -resistant MB49 CisR cells, with an IC 50 value of 12.7 μM.
Keyphrases
- induced apoptosis
- cell cycle arrest
- high resolution
- cell death
- molecular dynamics
- signaling pathway
- oxidative stress
- magnetic resonance imaging
- high intensity
- radiation therapy
- computed tomography
- density functional theory
- staphylococcus aureus
- pi k akt
- biofilm formation
- cystic fibrosis
- quantum dots
- solid state
- cell wall