Isolation, characterization, in silico docking, and in vitro cytotoxicity study of isolated triterpene constituents from Ehretia microphylla

Building on previous studies of Ehretia microphylla, we quantified key
phytochemicals rutin, gallic acid, and quercetin using high-performance
thin-layer chromatography (HPTLC), validated against standard references.
From chloroform extract, three triterpenes were isolated and structurally
characterized. These were identified as bauerenol (Compound A), 11-oxo
amyrin (Compound B, a novel triterpene), and β-sitosterol (Compound C).
In silico docking studies were performed with the cancer-related protein
(PDB: 1DB1), yielding binding scores of −9.50, −9.44, and −7.44, and with
the hepatoprotective target (PDB: 4FA6), with scores of −8.13, −8.42, and
−8.54, respectively. Compounds A and B exhibited significant anticancer
potential, while Compound C showed superior hepatoprotective activity. In
vitro cytotoxicity studies on HepG2 cells revealed IC₅₀ values of 455, 538,
and 556 μg/mL, and on NIH 3T3 cells, IC₅₀ values were 1068, 1153, and
1310 μg/mL, indicating selective toxicity toward cancer cells. These findings
highlight the therapeutic potential of triterpenes from E. microphylla, with
Compounds A and B for hepatocellular carcinoma treatment and Compound
C for hepatoprotection.