Ladanetin

New isoflavones from Gynandriris sisyrinchium and their antioxidant and cytotoxic activities.[Pubmed:26410237]

Fitoterapia. 2015 Dec;107:15-21.

Chemical investigation of Gynandriris sisyrinchium (L.) Parl growing in Jordan resulted in the isolation and characterization of a total of twelve compounds two of which are reported here for the first time in nature. These new compounds included the isoflavones; 3'-methyl tenuifone (2) and gynandrinone (5). In addition, ten known compounds including; beta-sitosterol (1), 7,3'-dimethoxy-5,6,4'-trihydroxyisoflavone (3), iristectorigenin (4), hispidulin (6), galangustin (7), 6-hydroxybiochanin A (8), ursolic acid (9), Ladanetin (10), 4'-O-methylgenistein (11) and beta-sitosterol glucoside (12) are also reported here for the first time from G. sisyrinchium. The isolated compounds were characterized by different spectroscopic methods including NMR (1D and 2D), UV, IR and MS (HRESIMS and EIMS). The antioxidant and cytotoxic activities of isoflavones 2, 3 and 5 were investigated. Compound 3 showed the highest antioxidant activity (IC50=17.3mug/mL), as compared to compounds 5 and 2 (IC50=26.7 and 51.7mug/mL, respectively). The cytotoxic activity against the human promyelocytic leukemia HL-60 cells revealed that compound 2 was the most active (40muM). The results indicate that the cytotoxicity of compound 2 is mediated by apoptosis.

Flavonoids from Dracocephalum tanguticum and their cardioprotective effects against doxorubicin-induced toxicity in H9c2 cells.[Pubmed:20932762]

Bioorg Med Chem Lett. 2010 Nov 15;20(22):6411-5.

Two new flavonoids, Ladanetin-6-O-beta-(6''-O-acetyl)glucoside (1) and pedalitin-3'-O-beta-glucoside (2), together with 15 known compounds (3-17), were isolated from the whole plants of Dracocephalum tanguticum. Their structures were established on the basis of extensive spectroscopic (IR, MS, 2D NMR) data analysis and by the comparison with spectroscopic data reported in the literature. Antioxidant capacities of the isolated substances were determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferrous ions, and ABTS(.)(+) radical in vitro assay, and their cytoprotective activities were also tested on doxorubicin (DOX)-induced toxicity in H9c2 cardiomyocytes. Among all the tested compounds, luteolin-7-O-beta-D-glucopyranoside (7) exhibited both strong antioxidative effect and high protective activity against DOX-induced toxicity. Further investigation found 7 could decrease DOX-induced death of H9c2 cell, reduce LDH and CK level, and inhibit the elevated intracellular concentration of ROS and [Ca(2+)](i). The preliminary structure-activity relationships (SAR) of these compounds revealed the Delta(2,3) double bond on C-ring and 3',4'-di-OHs on B-ring with a flavone skeleton such as luteolin and its derivatives, were necessary for their cardioprotective effects.

Flavones and flavone glycosides from Halophila johnsonii.[Pubmed:18771781]

Phytochemistry. 2008 Oct;69(14):2603-8.

Halophila johnsonii Eiseman is a shallow-water marine angiosperm which contains UV-absorbing metabolites. Studies on methanol extracts of H. johnsonii by means of HPLC-UV, NMR, HPLC-MS resulted in isolation and identification of seven previously unknown flavone glycosides: 5,6,7,3',4',5'-hexahydroxyflavone-7-O-beta-glucopyranoside (1), 5,6,7,3',4',5'-hexahydroxyflavone-7-O-(6''-O-acetyl)-beta-glucopyranoside (2), 6-hydroxyluteolin-7-O-(6''-O-acetyl)-beta-glucopyranoside (3), 6-hydroxyapigenin-7-O-(6''-O-acetyl)-beta-glucopyranoside (4), 6-hydroxyapigenin-7-O-(6''-O-[E]-coumaroyl)-beta-glucopyranoside (5), 6-hydroxyapigenin-7-O-(6''-O-[E]-caffeoyl)-beta-glucopyranoside (6) and 6-hydroxyluteolin-7-O-(6''-O-[E]-coumaroyl)-beta-glucopyranoside (7). Also isolated were three known flavone glycosides, 6-hydroxyluteolin 7-O-beta-glucopyranoside (8), scutellarein-7-O-beta-glucopyranoside (9), and spicoside (10), and five known flavones, pedalitin (11), Ladanetin (12), luteolin (13), apegenin (14) and myricetin (15). Qualitative comparison of the flavonoid distribution in the leaf and rhizome-root portions of the plant was also investigated, with the aim of establishing the UV-protecting roles that flavonoids played in the sea grass.

[Flavones from flowers of Sesamum indicum].[Pubmed:17583201]

Zhongguo Zhong Yao Za Zhi. 2007 Apr;32(7):603-5.

OBJECTIVE: To investigate the chemical constituents from flowers of Sesamum indicum. METHOD: Column chromatography with silica gel, C18 and Sephadex LH -20 as packing materials was used to separate the chemical constituents, and the structures were determined by chemical and spectroscopic methods. RESULT: Six flavones were isolated and elucidated as apigenin (1), Ladanetin (2), Ladanetin-6-O-beta-D-glucoside (3), apigenin-7-O-glucuronic acid (4), pedalitin (5), and pedalitin-6-O-glucoside (6). CONCLUSION: All of the compounds were isolated from this plant for the first time.