Abstract

Mosad Ahmed Ghareeb^1*, Amal Mohamed Saad¹, Allia Mahmoud Abdou¹, Laila Abdel-Ghany Refahy¹ and Wafaa Sabry Ahmed^1,2

DOI : http://dx.doi.org/10.13005/ojc/320626

The current study aimed to identify the chemical constituents of Chenopodium ambrosioides (Linn.), and the assessment of the in vitro antioxidant activity of the different extracts and pure isolates. Methods: The antioxidant activity was estimated via free radical scavenging and Phosphomolybdenum assays. Structure elucidation of pure compounds was achieved via UV, IR, ¹H & ¹³C-NMR, ¹H-¹H COSY, HMQC, and HMBC, spectroscopy. Bioassay-guided fractionation and isolation of the n-butanol fraction led to the isolation of a new kaempferol glycoside namely; kaempferol 3-O-α-L-¹C₄-rhamnosyl-(1'''→2'')-β-D-⁴C₁-xylopyranoside (1), together with five known compounds identified as; kaempferol 3-O-α-L-¹C₄–rhamnopyranoside (afzelin) (2), kaempferol 7-O-α-L-¹C₄–rhamnopyranoside (3), caffeic acid (4), 1,2-benzopyrone (coumarin) (5), and kaempferol (6). Compound (1) showed in vitro antioxidant activity of SC₅₀ 12.45 μg/ml, compared to ascorbic acid (AA) with SC₅₀ of 7.50 μg/ml. It can conclude that the leaves of C. ambrosioides can be used as promising natural antioxidants agents.

Chenopodiaceae; Chenopodium ambrosioides; kaempferol 3-O-α-L-1C4-rhamnosyl-(1'''→2'')-β-D-4C1-xylopyranoside; Antioxidant; DPPH; 2D-NMR

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