Thonningiiflavanonol A and thonningiiflavanonol B, two novel flavonoids, and other constituents of Ficus thonningii Blume (Moraceae).

A phytochemical study of Ficus thonningii has led to the isolation of two previously unreported compounds, thonningiiflavanonol A and thonningiiflavanonol B together with 16 known compounds: shuterin, naringenin, syringic acid, p-hydroxybenzoic acid, genistein, 5,7,3',4',5'-pentahydroxyflavanone, luteolin, methylparaben, aromadendrin, garbanzol, dihydroquercetin, 5,7,3'-trihydroxyflavanone, ß-sitosterol, sitosterolglucoside, lupeol acetate, and taraxerol. Their structures were elucidated on the basis of spectroscopic data. The new compounds and extracts displayed potent antioxidant activity.

Phosphodiesterase I-inhibiting Diels-Alder adducts from the leaves of Morus mesozygia.

A new 2-arylbenzofuran derivative, (+)-dimethylsmoracin O (1), and three new Diels-Alder type adducts, mesozygins A­C (2­4), in addition to eight known compounds, artonin I (5), chalcomaracin (6), norartocarpetin (7), moracin L (8), mulberrofuran F (9), moracin M (10), moracin C (11), and morachalcone A (12),were isolated from the leaves of Morus mesozygia Stapf. Structures were elucidated by spectroscopic data analyses. Compounds 2-7 displayed a potent phosphodiesterase I inhibitory activity.

Hepatoprotective and antioxidant arylbenzofurans and flavonoids from the twigs of Morus mesozygia.

The chemical investigation of the twigs of Morus mesozygia resulted in the isolation of three new prenylated 2-arylbenzofurans, named moracin KM, LM, and SC (1-3), nine known 2-arylbenzofurans (4-12), and two known flavonoids (13-14). The structures of the new compounds were established as [2'',3'':6,7]-(6-(S)-hydroxymethyl-6-methylpyrano)-2-(3,5-dihydroxyphenyl)benzofuran-5-ol (1), [2'',3'':6,7]-(4,7-dihydro-6-methyloxepine)-2-(3-hydroxy-5-methoxyphenyl)benzofuran-5-ol (2), and [2'',3'':6,7]-(6,6-dimethylpyrano)-2-(3,5-dihydroxyphenyl)benzofuran (3). One of the new compounds, moracin LM (2), displayed modest antioxidant activity, whereas known compounds 4, 13, and 14 showed significant hepatoprotective and antioxidant activities.

Prenylated arylbenzofuran derivatives from Morus mesozygia with antioxidant activity.

Five prenylated arylbenzofurans, moracins Q-U, were isolated from Morus mesozygia (Moraceae). Their structures were elucidated on the basis of spectroscopic evidence. Along with these compounds, 3beta-acetoxyurs-12-en-11-one, marsformoxide, moracin C, moracin M, moracin K, artocarpesin, cycloartocarpesin, morachalcone A were also isolated. Four of the five compounds, (moracins R-U) displayed potent antioxidant activity.

Cytotoxicity of three naturally occurring flavonoid derived compounds (artocarpesin, cycloartocarpesin and isobavachalcone) towards multi-factorial drug-resistant cancer cells.

INTRODUCTION: Cancer remains an aggressive deadly disease, if drug resistance develops. This problem is aggravated by the fact that multiple rather than single mechanisms are involved in resistance and that multidrug resistance (MDR) phenomena cause inefficacy of many clinical established anticancer drugs. We are seeking for novel cytotoxic phytochemicals to combat drug-resistant tumour cells. METHODS: In the present study, we investigated the cytotoxicity of three naturally occurring flavonoids including two flavones artocarpesin (1) and cycloartocarpesin (2) and one chalcone, isobavachalcone (3) against 9 drug-sensitive and MDR cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analysed via flow cytometry. RESULTS: Flavones 1 and 2 as well as chalcone 3 displayed cytotoxic effects at various extent on all the 9 tested cancer cell lines with IC50 values respectively below 106 µM, 50 µM and 25 µM. The IC50 values for the three investigational flavonoids ranged from 23.95 µM (towards hepatocarcinoma HepG2 cells) to 105 µM [towards colon carcinoma HCT116 (p53(-/-)) cells] for 1, from 15.51 µM (towards leukemia CCRF-CEM cells) to 49.83 µM [towards glioblastoma U87MG.ΔEGFR cells] for 2 and from 2.30 µM (towards CCRF-CEM cells) to 23.80 µM [towards colon carcinoma HCT116 (p53(+/+)) cells] for 3 and from 0.20 µM (towards CCRF-CEM cells) to 195.12 µM (towards leukemia CEM/ADR5000 cells) for doxorubicin. Compounds 2 and 3 induced apoptosis in CCRF-CEM leukemia cells, mediated by caspase activation and the disruption of MMP. CONCLUSIONS: The three tested flavonoids and mostly chalcone 3 are potential cytotoxic natural products that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug-resistant cancers.