Cytotoxic Activity and Related Mechanisms of Prenylflavonoids Isolated from Mallotus conspurcatus Croizat.

Five prenylflavonoids, 6-prenylnaringenin (1), 8-prenylnaringenin (2), 7-O-methyl-8-prenylnaringenin (3), 7-O-methyl-6-prenylnaringenin (4), and 4'-O-methyl-6-prenylnaringenin (5), were isolated from the traditional herb Mallotus conspurcatus Croizat (Euphorbiaceae). Compounds 1-5 revealed cytotoxic activity against cervical cancer (HeLa) cells with IC50 values ranging from 10.08 to 60.16 µm by MTT method, and interestingly, these prenylflavonoids were less toxic to normal HL-7702 cells. Furthermore, compounds 1 and 5 could inhibit the c-myc expression and telomerase activity and cause mitochondrial dysfunction. These findings might contribute to a better understanding of the biological activities of prenylflavonoids and lay the foundation for further studies on the cytotoxic activity of natural products isolated from M. conspurcatus.

Discovery of anti-inflammatory terpenoids from Mallotus conspurcatus croizat.

ETHNOPHARMACOLOGICAL RELEVANCE: Mallotus conspurcatus croizat (Euphorbiaceae), a plant native to Jinxiu in Guangxi, is popularly used in folk medicine to treat pelvic inflammatory disease. The anti-inflammatory activities of the compounds obtained from M. conspurcatus root were evaluated in this study. AIM OF THE STUDY: This study explored the major anti-inflammatory components of this plant. MATERIALS AND METHODS: The ethyl acetate fraction of the ethanol extract from M. conspurcatus was separated using chromatographic techniques. The structures of the isolates were elucidated from NMR, MS and X-ray data as well as from ECD. The anti-inflammatory activities of the isolates from M. conspurcatus were evaluated using LPS-stimulated RAW 264.7 cell models. The production of NO, TNF-α and PGE-2 was determined by ELISA and Griess tests. The expression levels of COX-2, NF-κB/p65 and iNOS were measured by western blotting. RESULTS: Two new diterpenoids, malloconspur A (1) and malloconspur B (2), and sixteen known terpenoids (3-18) were identified by comprehensive spectroscopic analyses and comparison with literature data. Malloconspur B (2) and 17-hydroxycleistantha-12,15-dien-3-one (3) substantially inhibited the release of NO with IC50 values of 10.47 µM and 9.32 µM, respectively. Compounds 1, 2 and 3 markedly decreased the secretion of PGE2 and TNF-α (P < 0.01) by LPS-induced RAW264.7 cells. Compounds 2 and 3 markedly decreased iNOS, NF-κB/p65 and COX-2 protein expression. CONCLUSIONS: Our identification of these diterpenoids provides strong evidence for the use of M. conspurcatus among the Yao people as a medicinal plant for the treatment of inflammation. The dramatic differences in the chemical structures of the active diterpenoids of this plant from those on the market suggest these compounds have potential as anti-inflammatory lead compounds for follow-up research.

Coumarins from Mallotus conspurcatus / 中国药学杂志

OBJECTIVE: To study the coumarins from Mallotus conspurcatus. METHODS: The ethyl acetate part of 75% ethanol extracts from Mallotus conspurcatus was isolated. The compounds were isolated and purified with column chromatography, and their structures were elucidated on the basis of 1H-NMR, 13C-NMR and ESI-MS data. RESULTS: Twelve coumarins were determined to be malloapelin A (1), 5'-demethyl aquillochin (2), aquillochin (3), cleomiscosin B (4), 6-hydroxy-7-methoxy-coumarin (5), braylin (6), aegelinol (7), bergapten (8), isofraxidin (9), fraxidin (10), grevillone (11), and fraxetin (12). CONCLUSION: Compounds 6-12 are isolated from this genus for the first time.

Chemical constituents of Mallotus conspurcatus / 中草药

Objective: To investigate the chemical constituents of Mallotus conspurcatus. Methods: The ethyl acetate part of 75% ethanol extracts from M. conspurcatus was separated through chromatographic techniques. The isolates were identified on the basis of 1H-NMR, 13C-NMR, and ESI-MS data. Results: Eighteen known compounds were isolated. They were 1,5-dihydroxy-3-methoxy-7- methyl-anthraquinon (1), (-)-syringaresinol (2), 2,3-dihydro-5,7-dihydroxy-2,8-dimethyl-6-(3-methyl-2-butenyl)-4H-1-benzo-4-one (3), 2,3-dihydro-5,7-dihydroxy-2,6,8-tri-methyl-4H-1-benzopyran-4-one (4), paeoveitol B (5), pinellic acid (6), trans-p- hydroxycinnamic acid (7), trans-p-methoxycinnamic acid (8), trans-p-hydroxy-ethyl cinnamate (9), p-hydroxybenzoic acid (10), 3-methoxy-4-hydroxybenzoic acid (11), 3,4-dihydroxybenzoic acid (12), ferulic acid (13), syringic acid (14), syringic acid ethyl ester (15), hexadecanoic acid 2,3-dihydroxy-propyl ester (16), galic acid (17), and ethyl gallate (18). Conclusion: Besides compounds 3, 4, and 13, the other compounds are isolated from the plants of Mallotus Lour. for the first time.