Flavonoids of Retama sphaerocarpa leaves and their antimicrobial activities

Abstract

UDC 547.972 Retama sphaerocarpa (Fabaceae), known in Algeria as "Retam", was collected during flowering in the Souk Naamane Region east of Algeria in June 2002, and the species was identified by Dr. H. Laouer from the Department of Biology (University of Setif, Algeria) on the basis of Quezel and Santa (1963) [1]. A voucher specimen (P00383267) has been deposited in the Herbarium of Museum National d'Histoire Naturelle, Paris, FranceThis research is a contribution to the chemical study of some plants growing in Algeria, with the objective of discovering natural products with potential biological activity. As part of our continuing study of Retama sphaerocarpa [2] we have undertaken a reexamination of the chemical constituents of the aerial parts and roots of R. sphaerocarpa. We report here the isolation and identification of two flavonoids; these compounds are new for this genus. The leaves of Retama sphaerocarpa were investigated for antimicrobial properties. All fractions showed activity against Staphylococcus aureus.Air-dried powder from the aerial parts (950 g) of R. sphaerocarpa was extracted three time with boiling 70% MeOH. The MeOH extract was evaporated to dryness.The residue was dissolved in boiling water and extracted with ethyl acetate and n-BuOH successively. The solvents was evaporated. and the residue of the ethyl acetate and n-BuOH extracts was dissolved in small volumes of MeOH. Analysis by two-dimensional paper chromatography using 15% AcOH and BAW (n-BuOH-AcOH-H 2 O 4:1:5 upper phase) as solvents revealed identical separation of the flavonoids in the acetate and n-BuOH extracts. The n-BuOH extract was applied to a column of polyamide MN SC6 and eluted with a gradient of toluene-MeOH with increasing polarity. Two flavonoids (1, 2), contained in several fractions, were isolated by preparative PC on whatman 3MM paper using AcOH 15%, then by preparative TLC on polyamide DC6 eluted with (H 2 O-MeOH-methylethylacetone:acetylacetone) 13:3:3:1.Purification of each compound for spectral analysis was carried out using MeOH over Sephadex LH-20. The chemical structures of the compounds were determined using UV, 1D, and 2D NMR spectrometry.

Ultrasonic-assisted extraction for phenolic compounds and antioxidant activity of Moroccan Retama sphaerocarpa L. leaves: Simultaneous optimization by response surface methodology and characterization by HPLC/ESI-MS analysis

“…The MS spectra of compound 8 presented a molecular ion signal at m / z 431 and a fragmentation pattern signals consistent with genistein hexoside product [ 65 ]. This is consistent with previously reported data on R. sphaerocarpa, revealing the presence of genistein derivatives in R. sphaerocarpa [ 66 ]. Such derivatives were reported as the most abundant components in Retama species [ 67 ] and are known to exhibit high antioxidant power [ 68 ].…”

Phytochemical analysis of Ononis arvensis L. by liquid chromatography coupled with mass spectrometry

“…Cuneatin was described in aerial parts of Millettia oblata ssp. teitensis , aerial parts of Retama sphaerocarpa , stem bark of Dalbergia frutescens , Eysenhardtia polystachya , aerial parts and roots of Tephrosia maxima and most importantly, in Cicer species . In his other work, Ingham had shown the chemotaxonomic similarity of genus Ononis and Cicer , and the presence of cuneatin in both genus corroborates this idea.…”

First Occurrence of Megastigmane Glucosides in a Plant of Retama Genus

“…Given the environmental importance as well as the use in folk medicine, R. sphaerocarpa has been object of several chemical, ethnobotanical, and pharmacological studies [10] . The literature reveals that the chemistry of this plant is typically characterized by the presence of isoflavonoids [11–13] and quinolizidine alkaloids, [13–15] mainly, in accordance with the secondary metabolite profile of other Retama species. In addition, fatty acids, sterols, aliphatic alcohols, and terpenoids have been also reported in several phytochemical studies conducted on samples from distinct geographical areas.…”