Polycyclic polyprenylated acylphloroglucinols (PPAPs) represent a distinct subclass of specialized metabolites predominantly found in the plant kingdom, particularly within the Guttiferae (Clusiaceae) family. These compounds exhibit remarkable structural diversity and a wide range of biological activities. Seco- and nor-PPAPs, two unique variants of PPAPs with diverse skeletal structures, have been extensively investigated. As of June 2023, 200 compounds have been isolated from four genera, with Hypericum being the primary source. Notably, 115 of these compounds were identified in the past four years, indicating a significant increase in research activity. Seco- and nor-PPAPs can be categorized into six main subgroups based on the original PPAP scaffolds. Biological studies have revealed their potential in various therapeutic applications, including anti-cancer, anti-inflammatory, hepatoprotective, anti-Alzheimer's disease (anti-AD), multidrug resistance (MDR) reversal, anti-depressant, neuroprotective, and immunosuppressive effects. This review provides a comprehensive overview of the occurrence, structures, and bioactivities of natural seco- and nor-PPAPs, offering valuable insights for the further development of PPAPs.
Phloroglucinol/analogs & derivatives* ; Humans ; Molecular Structure ; Animals ; Clusiaceae/chemistry* ; Plant Extracts/pharmacology* ; Biological Products/pharmacology*

The chemical constituents from the stems and leaves of Cratoxylum cochinchinense were isolated and purified using silica gel, ODS gel, and Sephadex LH-20 gel column chromatography, as well as preparative HPLC. The chemical structures of all isolated compounds were identified on the basis of their physicochemical properties, spectroscopic analyses, and the comparison of their physicochemical and spectroscopic data with the reported data in literature. As a result, 21 compounds were isolated from the 90% ethanol extract of the stems and leaves of C. cochinchinense, which were identified as cratocochine(1), 1-hydroxy-3,7-dimethoxyxanthone(2), 1-hydroxy-5,6,7-trimethoxyxanthone(3), ferrxanthone(4), 3,6-dihydroxy-1,5-dimethoxyxanthone(5), 3,6-dihydroxy-1,7-dimethoxyxanthone(6), 1,2,5-trihydroxy-6,8-dimethoxyxanthone(7), securixanthone G(8), gentisein(9), 3,7-dihydroxy-1-methoxyxanthone(10), pancixanthone B(11), garcimangosxanthone A(12), pruniflorone L(13), 9-hydroxy alabaxanthone(14), cochinchinone A(15), luteolin(16), 3,5'-dimethoxy-4',7-epoxy-8,3'-neolignane-5,9,9'-triol(17), N-benzyl-9-oxo-10E,12E-octadecadienamide(18), 15-hydroxy-7,13E-labdadiene(19), stigmasta-4,22-dien-3-one(20), and stigmast-5-en-3β-ol(21). Among these isolates, compound 1 was a new xanthone, compounds 2-5, 7, 8, 12, and 16-21 were isolated from the Cratoxylum plant for the first time, and compounds 11 and 13 were obtained from C. cochinchinense for the first time. Furthermore, all isolated compounds 1-21 were appraised for their anti-rheumatoid arthritis activities by MTS method through measuring their anti-proliferative effect on synoviocytes in vitro. As a result, xanthones 1-15 displayed notable anti-rheumatoid arthritis activities, which showed inhibitory effects on the proliferation of MH7A synoviocytes with the IC_(50) values ranging from(8.98±0.12) to(228.68±0.32) μmol·L~(-1).
Synoviocytes ; Clusiaceae/chemistry* ; Xanthones/analysis* ; Plant Leaves/chemistry* ; Cell Proliferation ; Arthritis