methyl-3-methoxy-4-hydroxystyryl-ketone and zingerone

Curcumin, a dietary polyphenol, has shown a potential to act on the symptoms of neurodegenerative disorders, including Alzheimer's and Parkinson's diseases, as a consequence of its antioxidant, anti-inflammatory and anti-protein aggregation properties. Unfortunately, curcumin undergoes rapid degradation at physiological pH into ferulic acid, vanillin and dehydrozingerone, making it an unlikely drug candidate. Here, we evaluated the ability of some curcumin by-products: dehydrozingerone (1), its O-methyl derivative (2), zingerone (3), and their biphenyl analogues (4-6) to interact with α-synuclein (AS), using CD and fluorescence spectroscopy. In addition, the antioxidant properties and the cytoprotective effects in rat pheochromocytoma (PC12) cells prior to intoxication with H2O2, MPP+ and MnCl2 were examined while the Congo red assay was used to evaluate the ability of these compounds to prevent aggregation of AS. We found that the biphenyl zingerone analogue (6) interacts with high affinity with AS and also displays the best antioxidant properties while the biphenyl analogues of dehydrozingerone (4) and of O-methyl-dehydrozingerone (5) are able to partially inhibit the aggregation process of AS, suggesting the potential role of a hydroxylated biphenyl scaffold in the design of AS aggregation inhibitors.

Topics: Adrenal Gland Neoplasms; alpha-Synuclein; Alzheimer Disease; Animals; Antioxidants; Cell Line, Tumor; Curcumin; Cytoprotection; Guaiacol; Parkinson Disease; Pheochromocytoma; Rats; Styrenes

One new quinoline alkaloid and seven known bisabolane sesquiterpenes: 2-(2'-methyl-1'-propenyl)-4, 6-dimethyl-7-hydroxyquinoline (1), 2, 5-dihydroxybisabola-3, 10-diene (2), 4, 5-dihydroxybisabola-2,10-diene (3), turmeronol A (4), bisacurone (5), bisacurone A (6), bisacurone B (7) , bisacurone C (8), as well as dehydrozingerone (9) and zingerone (10) were isolated from the root tuber of Curcuma longa. Their structures were identified by spectral evidence. Compound 1 is a new compound, compounds 6 -8 were isolated from this plant for the first time and compounds 9 - 10 from Curcuma for the first time.

Topics: Alkaloids; Curcuma; Cyclohexanols; Guaiacol; Molecular Structure; Plant Tubers; Plants, Medicinal; Sesquiterpenes; Styrenes

Fresh rhizomes of Zingiber officinale (ginger), when subjected to steam distillation, yielded ginger oil in which curcumene was found to be the major constituent. The thermally labile zingiberene-rich fraction was obtained from its diethyl ether extract. Column chromatography of ginger oleoresin furnished a fraction from which [6]-gingerol was obtained by preparative TLC. Naturally occurring [6]-dehydroshogaol was synthesised following condensation of dehydrozingerone with hexanal, whereas zingerone and 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)butane were obtained by hydrogenation of dehydrozingerone with 10% Pd/C. The structures of the compounds were established by 1H NMR, 13C NMR and mass (EI-MS and ES-MS) spectral analysis. The test compounds exhibited moderate insect growth regulatory (IGR) and antifeedant activity against Spilosoma obliqua, and significant antifungal activity against Rhizoctonia solani. Among the various compounds, [6]-dehydroshogaol exhibited maximum IGR activity (EC50 3.55 mg ml-1), while dehydrozingerone imparted maximum antifungal activity (EC50 86.49 mg litre-1).

Topics: Animals; Antifungal Agents; Catechols; Fatty Alcohols; Feeding Behavior; Guaiacol; Insect Control; Insecticides; Larva; Lepidoptera; Magnetic Resonance Spectroscopy; Mass Spectrometry; Mutagens; Plants, Medicinal; Styrenes; Zingiber officinale