Anthraquinones (ANQs)
isolated from Paederia plants are known
to have antidiarrheal, antitussive, anthelmintic,
analgesic, anti-inflammatory, antihyperlipidemic, antihyperglycaemic,
and antimicrobial activities. The antioxidant properties were also
noted but not confirmed thus far. In this study, the superoxide and
hydroperoxide radical scavenging activities of six ANQs were evaluated
using a computational approach. The results suggest that the ANQs
exhibit low HOO• antiradical activity in all environments,
including the gas phase (k < 102 M–1 s–1). In contrast, the ANQs might
exert excellent O2
•– radical scavenging
activity, particularly in aqueous solution. The rate constants of
the superoxide anion scavenging in water (at pH = 7.4) range from
3.42 × 106 to 3.70 × 108 M–1 s–1. Compared with typical antioxidants such as
ascorbic acid and quercetin, the superoxide anion scavenging activity
of ANQs is significantly higher. Thus, the ANQs are promising O2
•– radical scavengers in polar media.
ABSTRACT. Surveys on the process of extracting acid from dried rinds of Garcinia oblongifolia Champ. ex Benth (G. oblongifolia) using microwave in terms of time, machine power and solid/liquid rate, have resulted in such findings as: the best time allocation for extracting is 25 minutes; machine power works best at level 2 (microwave power is 400 W); suitable rate of solid/liquid is 0.071 (approximately 150 mL solvent per 10 g of sample). The total amounts acid and (-)-hydroxycitric acid extracted from 100 g dried rinds of G. oblongifolia are 18.592 g and 10.137g respectively. This is the first finding on extraction of (-)-HCA from dried rinds of G. oblongifolia using microwave.
Male Carica papaya flowers, one of natural materials, have many pharmacology activities including anticancer. We report herein the isolation and structural elucidation of known compounds. Eight flavonoids, kaempferol (1), (4), quercetin (5), quercitrin (6), quercetin 3-O-β-D-galactopyranoside (7) and myricitrin (8) were isolated from the ethyl acetate extract of male Carica papaya flowers. Their structures were determined by NMR, MS spectra and by comparing with the reported data.
A new phenolic (caricapapayol, 1) and 8 known compounds (2-9) were isolated from the flowers of Carica papaya. Their structures were determined by analysis of HR-ESI-MS, NMR spectral data, and comparison with the literature. Among known compounds, compound 2 has not been reported from natural source. Compounds 1, 2, and 4 exhibited tyrosinase inhibitory activity with IC50 values of 14.3 ± 2.7, 25.5 ± 1.9, and 19.8 ± 3.0 µM, respectively, in comparison with positive control kojic acid IC50 11.3 ± 1.6 µM.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.