Cytotoxic 7‐Methoxylated Caged Xanthones from the Twigs of Garcinia oligantha

Abstract

Main observation and conclusion Nineteen unprecedented 7‐methoxylated caged xanthones (1—19) were isolated from the twigs of Garcinia oligantha under the guidance of NMR spectroscopy. Their structures and absolute configurations were demonstrated by extensive spectroscopic data, single‐crystal X‐ray diffraction, electronic circular dichroism (ECD) calculations, and the modified Mosher's method. Compound 1 is a rare scalemic 7‐methoxylated neo‐caged xanthone, which was resolved using HPLC with CD detection on a chiral‐phase AD column, and compounds 2—3 are rare 7‐methoxylated caged xanthones with the hydrogenated Δ8(8a) double bond. Fourteen compounds exhibited promising inhibitory activities against four human cancer cell lines with IC50 values ranging from 1.9 to 14.3 μmol/L. A cell apoptosis analysis using flow cytometry showed that compound 11 could induce apoptosis in a dose dependent manner. Moreover, PARP, caspase‐9, and Bcl‐2 western blotting suggested that compound 11‐induced apoptosis may be involved in caspase‐dependent pathway.

Biphenyls in Clusiaceae: Isolation, structure diversity, synthesis and bioactivity

“…Garcinia oligantha is a tall shrub mainly growing in the Guangdong and Hainan provinces of China and northern Vietnam ( Li et al, 2011 ). The plant was usually explored for the bioactive xanthones possessing diverse activity such as cytotoxic property and suppressing convulsant behavior ( Tang et al, 2016 ; Tang et al, 2019 ; Gong et al, 2020 ; Yang et al, 2021 ). The biphenyl ( 29 ) was measured for its cytotoxic effects against NB4, A549, SHSY5Y, PC-3 and MCF-7 tumor cells.…”

Elodexanthones A—J, Isoprenylated Xanthone Derivatives with Diverse Skeletons and Bioactivities from Hypericum elodeoides

“…Their structures varied due to the hydrogenated xanthone core as well as the oxidation and cyclization of isopentenyls to create novel caged xanthone derivatives. [ 5‐8 ] In recent decades, isoprenylated xanthones have been identified with notable biological activities, including antibacterial, antidepressant, antidiabetic and anticancer activities. [ 3,7,9‐12 ] Chemistry and pharmacology researchers have given isoprenylated xanthones considerable attention due to their complicated structures and noteworthy bioactivities.…”

Triterpene Derivatives from Garcinia oligantha and Their Anti-Cancer Activity

“…G. oligantha , a 1–3 m tall shrub, has been used as a traditional Chinese herbal medicine to treat fevers, toothaches, and scalds [ 40 ]. Previous phytochemical investigations of the plant led to the isolation of many xanthone derivatives with anti-cancer and/or anti-inflammatory activities [ 4 , 10 , 41 , 42 ], but triterpenoids were rarely reported from it.…”