Structurally Diverse Cytotoxic Polyphenols from Garcinia gracilis

Thirty-five
diverse polyphenols, belonging to seven structure classes,
were isolated from Garcinia gracilis, a medicinal and edible plant sampled from Laos. The structures
of nine new compounds, gargarcilones A–I (1–3, 5–7, 10, 12, and 17), were established using spectroscopic,
X-ray diffraction, and experimental and calculated ECD methods. Additionally,
we revised the stereochemical assignment of cochinchinoxanthone and
cochinchinoxanthone C. The compounds were evaluated for antiproliferative
activity against five human tumor cell lines (HL-60, A549, SMMC-7721,
MDA-MB-231, and SW480). Compounds 1–4, 7, and 8 exhibited cytotoxic activity
with IC50 values of 0.5–8.9 μM. Compound 3 significantly induced apoptosis in SMMC-7721 cells.