Bioassay-guided isolation and characterisation of anti-proliferative compounds from Coelogyne kouytcheensis (Gagnep.) M.W.Chase & Schuit. using human lung cancer cell lines.

A phytochemistry investigation on bioassay-guided fraction led to the isolation of one new stilbene derivative, coelogynene A (1), along with six known compounds: phochinenin B (2), 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (3), (E)-2',3,3'-trihydroxy-5-methoxystilbene (4), trans-3,3',5-trihydroxy-2-methoxystilbene (5), cis-3,3'-trihydroxy-5-methoxystilbene (6), and 3',4',5'-trimethoxycinnamyl alcohol (7) from Coelogyne kouytcheensis (Gagnep.) M.W. Chase & Schuit. (synonym: Pholidota yunnanensis Rolfe). Their structures were identified based on extensive spectroscopic analysis. To determine their in vitr antiproliferative effects, the isolates were screened against both A549 and cisplatin-resistant A549/DDP cell lines using sulforhodamine B (SRB) assay. As a result, only compound 2 exhibited potent inhibitory activity (IC₅₀ = 4.22 ± 0.07 μM and 6.51 ± 0.27 μM) comparable to cisplatin (4.24 ± 0.20 μM and 20.02 ± 1.48 μM), while compound 3 showed moderate activity (24.14 ± 1.78 μM and 66.43 ± 3.28 μM). These preliminary results suggest that C. kouytcheensis may contain diverse phenanthrene derivatives with anti-lung cancer potential, thereby meriting further investigation.