Melicodenine I, a new quinolinone alkaloid from Melicope denhamii leaves.

A new quinolinone alkaloid, Melicodenine I (1), along with five known compounds, bergapten (2), isoevodionol methyl ether (3), isoevodionol (4), ternatin (5), ß-sitosteryl-3-O-ß-D-glucopyranoside (6) and a mixture of ß-sitosterol and stigmasterol were isolated from Melicope denhamii leaves, and their structures were elucidated using 1H NMR, 13C NMR, 2D NMR and UPLC-qToF-MS.

Nutritional properties of the largest bamboo fruit Melocanna baccifera and its ecological significance.

Melocanna baccifera is a unique bamboo which produces the largest fruits in the grass family. Its gregarious flowering once in 45-50 years in north east India and adjacent regions is a botanical enigma, resulting in a glut of fruits. Proper utilization of M. baccifera fruits is not extant, and huge quantities of fruits are left underexploited due to lack of scientific information on their chemical composition and nutritional potential. Here we report the nutritional properties of M. baccifera fruits, and the ecological significance of its fruiting. This pear-shaped, fleshy bamboo fruit is rich in amino acids (lysine, glutamic acid), sugars (sucrose, glucose, fructose) and phenolics (ferulic acid). Protein content (free, bound) in M. baccifera fruits is very low. Fruits are rich in saturated fatty acids (palmitic acid), minerals (potassium), and only B series vitamins (B3) are detected in them. Rat feeding experiments showed that M. baccifera fruit alone is not a complete food, but with other protein supplements, it is a valuable food additive. This study could lead to better utilization of M. baccifera fruits during future flowering/fruiting events. These results could also help in the successful management of rodent outbreaks and other ecological problems associated with M. baccifera fruiting.

A new lupane-type triterpenoid fatty acid ester and other isolates from Ophiorrhiza shendurunii.

A new pentacyclic triterpenoid fatty acid ester, lupan-20-ol-3(ß)-yl hexadecanoate (1), together with lupan-20-ol-3(ß)-yl acetate (2), olean-18-en-3(ß)-yl hexadecanoate (3), dotriacontanoic acid (4), stigmasterol (5), rubiadin (6), nonadecanoic acid (7), palmitic acid (8) and camptothecin (9) were isolated from the hexane and chloroform extracts of Ophiorrhiza shendurunii from South India. Structures of the isolates were determined by (1)H, (13)C, (13)C DEPT, (1)H-(1)H COSY, HMBC, HSQC, NOESY NMR, FT-IR, DART-MS, ESI-MS, alkaline hydrolysis, derivatisation, GC-MS and HPTLC analyses. O. shendurunii hexane and chloroform extracts showed significant activities against Candida albicans and Fusarium oxysporum. Compounds 1 to 3 showed only moderate antiyeast/antifungal activities.

O-prenylated flavonoid, an antidiabetes constituent in Melicope lunu-ankenda.

ETHNOPHARMACOLOGICAL RELEVANCE: Melicope lunu-ankenda leaves are used to treat diabetes in folklore medicinal practices in India and Malaysia. Here we report the isolation of an O-prenylated flavonoid (3,5,4'-trihydroxy-8,3'-dimethoxy-7-(3-methylbut-2-enoxy)flavone; OPF) from the leaves of M. lunu-ankenda and its antidiabetes activity against type-2 diabetes mellitus (T2DM). MATERIALS AND METHODS: OPF was isolated from M. lunu-ankenda leaves by extraction and repeated column chromatography and its structure was elucidated by IR, UV-vis, 1D-, 2D-NMR and mass spectral analyses. Blood glucose lowering activity of OPF was tested in normal rats by oral glucose tolerance test and its efficacy was tested in STZ-induced type-2 diabetic rats. SGOT, SGPT, ALP, serum urea, total triglycerides, total cholesterol and reduction in HDLC, protein and serum insulin levels in normal rats and STZ-induced type-2 diabetic rats were measured. Acute toxicity of OPF was tested at 500 mg/kg dose. Mechanism of antidiabetes action of OPF was elucidated by insulin release from RIN 5F cells. RESULTS: OPF isolated from M. lunu-ankenda showed significant blood glucose lowering activity in oral glucose tolerance test on overnight fasted, glucose loaded normal rats and the optimum activity was observed at a dose of 10mg/kg body weight. In neonatal streptozotocin (STZ) induced diabetic rats, the OPF treatment for 20 days significantly ameliorated the derailed blood glucose levels, liver glycogen and serum biological parameters including insulin to normal levels. OPF on acute toxicity evaluation did not show any conspicuous toxic symptoms even at a higher dose of 500 mg/kg body weight in mice. On evaluating the mechanism of antidiabetes action, it was observed that, OPF induced insulin release from cultured RIN 5F cells in vitro from which it was evident that the OPF acts on pancreatic ß-cells for insulin release thereby correcting the derailed blood glucose levels, serum biochemical parameters and ameliorate various diabetic complications in STZ-induced diabetic rats. CONCLUSIONS: This study shows the potent antidiabetes activity of OPF and describes its mechanism of action. OPF is a promising candidate for the development of new generation anti-DM drugs. Isolation of the O-prenylated flavonoid justifies the use of M. lunu-ankenda for diabetic treatments in folklore practices.

Chemical composition, antibacterial and anticancer activities of volatile oil of Melicope denhamii leaves.

Melicope denhamii leaf volatile oil was isolated by hydrodistillation, and twenty-six constituents comprising 95.95% of the leaf oil were characterised by gas chromatographic techniques. Sesquiterpenes, zierone (22.49%) and α-gurjunene (19.96%), were identified as the major components. M. denhamii leaf oil tested against Gram-positive and Gram-negative bacteria showed significant activity against Bacillus subtilis and Escherichia coli. Anticancer activity of M. denhamii leaf oil against Dalton's lymphoma ascites cells was assessed by trypan blue exclusion and MTT assays, and the oil showed significant cytotoxicity at CD50 of 12.2 µg/mL. Induction of apoptosis on DLA cells by M. denhamii leaf oil was confirmed by morphological observation, nuclear damage and comet assays.