Showing papers on "Piperlonguminine published in 2007"

Antifungal amides from Piper scutifolium and Piper hoffmanseggianum.

Abstract: Chromatographic fractionation of a dichloromethane extract from the leaves of Piper scutifolium yielded two new isobutyl amides, scutifoliamide A (1) and scutifoliamide B (2), together with the known compounds piperolactam C (3), piperovatine (4), piperlonguminine (5), corcovadine (6), isopiperlonguminine (7), and isocorcovadine (8). From the dichloromethane extract from the leaves of P. hoffmannseggianum two new isobutyl amides, hoffmannseggiamide A (9) and hoffmannseggiamide B (10), were obtained together with the known compounds isopiperlonguminine (7) and isocorcovadine (8), sitosterol, and stigmasterol. The structures of the new compounds were established on the basis of spectroscopic data analysis. The inhibitory activity of compounds 1−10 against the growth of the fungi Cladosporium sphaerospermum and C. cladosporioides was determined by bioautography.

Inhibition of beta-amyloid precursor protein gene in SK-N-SH cells by piperlonguminine/dihydropiperlonguminine components separated from Chinese herbal medicine Futokadsura stem.

Abstract: Alzheimer disease (AD) is a progressive neurodegenerative disease characterized by progressive cognitive and memory decline. Amyloid precursor protein (APP) is a transmembrane protein, it has been known to play an important role in AD pathogenesis. Previous studies have shown that a Chinese herb Futokadsura stem can selectively inhibit the expression of amyloid precursor protein (APP) gene. We want to find the effective components in Futokadsura stem which have the inhibitory effect. Futokadsura stem was separated and purified with chemical methods, and then different separation components were added on SK-N-SH cells in different concentrations. Using MTT methods, we detected proliferation activity of SK-N-SH cells which were treated with different separation components of Futokadsura stem. Using RT-PCR, Western blot methods, we detected APP gene expression in SK-N-SH cells after they are treated with different Futokadsura stem separation components. We found that piperlonguminine/dihydropiperlonguminine components (1:0.8) separated from Futokadsura stem acetic ether extracts could selectively inhibit the expression of APP gene in SK-N-SH cells in mRNA and protein levels. This inhibition effect is concentration-dependent. Under experimental concentrations, the components did not affect the proliferation activity of SK-N-SH cells. These data suggest that piperlonguminine/dihydropiperlonguminine components are the effective components in Futokadsura stem which can inhibit the expression of APP gene.

Novel preparation method for preparing piperlonguminine compound having skin whitening activity

Abstract: A method for preparing a piperlonguminine compound is provided to be able to simply mass-produce the piperlonguminine compound having strong whitening activity as an alpha-melanocyte stimulating hormone inhibitor. The method comprises the steps of: (a) after treating an ethyl-4-diethylphosphono-2-butenoate with NaH, performing a modified Wittig condensation on it with a piperonal represented by the formula(2) to obtain an ethyl piperate represented by the formula(4); (b) hydrolyzing the ethyl piperate(4) with a strong base such as KOH so as to obtain a piperinic acid represented by the formula(5); and (c) reacting the piperinic acid(5) with an isobutyl amine in the presence of a boronic acid to obtain a piperlonguminine compound represented by the formula(1a).