Cinnamic Ester Derivatives from Oxalis pes-caprae (Bermuda Buttercup)

Abstract

Seven new cinnamic ester derivatives ( 1- 7) were isolated from a methanol extract of the fresh leaves and twigs of Oxalis pes-caprae (Bermuda buttercup). The structures of these new compounds were determined by spectroscopic data interpretation. The effects of compounds 1- 7 on the germination and growth of Lactuca sativa (lettuce) were studied.

Recent advances in allelopathy for weed control: from knowledge to applications

“…Among the phenolics discovered, cinnamic ester derivatives are worth highlighting because of their phytotoxicity against standard target species (STS) such as lettuce . 2‐Hydroxyethyl caffeate, isolated from Oxalis pes‐caprae , was the most active cinnamic ester …”

Evaluation of Anti‐oxidant Activity and Identification of Major Polyphenolics of the Invasive Weed Oxalis pes‐caprae

“…Oxalis acetosella is rich in b-carotene, ascorbic acid, tocopherols and xanthophylls and one of the most prolific sources of flavonoids (flavonol glycosides and flavan-3-ols), especially rutin (Sircelj et al, 2010). The isolation and characterisation of new potential allelochemicals from O. pes-caprae (Bermuda buttercup), an invasive alien weed in Italy, Greece, the Iberian Peninsula and North Africa, have been reported recently (DellaGreca et al, 2007(DellaGreca et al, , 2008(DellaGreca et al, , 2009(DellaGreca et al, , 2010.…”

Phytotoxic Aromatic Constituents of Oxalis pes‐caprae

“…The invasiveness of plant communities (i.e., the intrinsic vulnerability to invasion) is strongly influenced by the competition for available resources (e.g., water, nutrients, and light) and plant -plant interactions [5]. Oxalis invasion may partially depend on its sensitivity to nutrient availability and to competitive interactions with dominant native species [6].The isolation and characterization of various compounds of Oxalis pes-caprae have been reported [7] [8]. Continued investigation of constituents with potential allelopathic activity from this plant led to the isolation of a cinnamic acid ester, 1, two dihydrocinnamic acid esters, 2 and 3, a noroxyneolignan, 4, a dibenzyl ether derivative, 5, along with common aromatic compounds as cinnamic and dihydrocinnamic acids, phenols, 4-hydroxybenzoic acid, 1,2,3,4-tetrahydro-1-methyl-b-carboline-3-carboxylic acid, and flavonoids.…”

“…Further known compounds were identified as flavones: 5,6,7,8,4'-pentamethoxyflavone (tangeretin, 16), 5,6,7,8,3',4'-hexamethoxyflavone (nobiletin, 17), 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (5-demethylnobiletin, 18), and 4'-hydroxy-5,6,7,8,3'-pentamethoxyflavone (4'-demethylnobiletin, 19) by comparison with previously reported spectroscopic data [10 -12]. All these compounds were isolated for the first time from O. pes-caprae.…”