Samwirin A (SW), a natural compound isolated from Sambucus williamsii or Rourea harmandiana, is known to exhibit potent antiosteoporosis activity and promote cell proliferation in rat osteoblast-like UMR 106 cells. Antiosteoporosis activity suggests that the compound must also exhibit antioxidant activity but this has not been studied thus far. In the present study, the antioxidant activity of SW was examined by experimental and computational studies. It was found that SW exhibits good hydroperoxyl scavenging activity, particularly in water at physiological pH (k overall = 1.01 × 107 M–1 s–1). The single-electron transfer mechanism defines the HOO• + SW reaction in water, while the activity in the lipid medium is moderate and it follows the formal hydrogen transfer mechanism. The rate constant of the HOO• scavenging reaction in the aqueous solution is about 78 times higher than the reference compound Trolox. The computational results are in line with experimental data underscoring that SW is a promising radical scavenger in aqueous media at physiological pH.
Phytochemical study of Rourea oligophlebia stems led to the isolation of a new 2-pyrrolidone alkaloid (R,S)-N-(5-hydroxyl-pyrrolidin-2-one-1-yl)acetamide (1), together with 14 known compounds including friedelin (2), friedanol (3), taraxerol (4), vanillin (5), coniferyl aldehyde (6), apigenin (7), 7α-hydroxy-3β-sitosterol (8), coniferyl alcohol (9), scopoletin (10), emodin (11), protocatechuic acid (12), catechin (13), procyanidin A1 (14), and (E)-2,3,5,4’-tetrahydroxystilbene-2-β-D-glucoside (15). Several isolated compounds were evaluated for cytotoxicity and antimicrobial activity. Compound 11 exhibited good antimicrobial activity on Gram (+) strains and moderate cytotoxicity against KB, Hep-G2, and LU cancer cell lines. Compounds 6 and 8–10 showed selective activity on HepG-2 and MCF-7 over KB and LU cancer cell lines, while compound 7 exhibited similar effects on KB, HepG-2, and MCF-7 cell lines with IC50 values of 36.46 ± 0.81, 32.00 ± 0.58, and 32.03 ± 0.61 µg/mL, respectively.
The sesquiterpenoid compound abelsaginol ( AS ) was successfully isolated from Abelmoschus sagittifolius for the first time. The compound was identified using NMR and MS data. The antioxidant activity of AS was also evaluated both theoretically and experimentally. AS was found to be a weak HOO • radical scavenger in organic solvents such as pentyl ethanoate and dimethyl sulfoxide ( k overall = ∼ 10 2 M –1 s –1 ), in a good agreement with the results of the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay. However, AS exhibited good HOO • antiradical activity in water at pH 7.40 ( k overall = 9.00 × 10 6 M –1 s –1 ) through the single-electron transfer mechanism of the anion state. Further calculations also demonstrated that AS could exert good to moderate activity against CH 3 O • , CH 3 OO • , CCl 3 OO • , NO 2 , and SO 4 •– radicals, with k f values from 4.00 × 10 3 to 1.52 × 10 7 M –1 s –1 . However, AS exerted much lower activity against HO • , CCl 3 O • , NO, O 2 •– , and N 3 • radicals under the studied conditions. In general, the activity of AS in water at pH 7.40 is higher than that of Trolox or butylated hydroxytoluene, which are common reference antioxidants. Thus, in an aqueous physiological milieu, AS is a promising natural antioxidant.
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.