Phytochemical Profile and Antibacterial Activity of Retama raetam and R. sphaerocarpa cladodes from Algeria

Abstract

Retama raetam (RR) and R. sphaerocarpa (RS) are shrubs growing in Algeria desert areas, where are commonly used as healing remedies because of their antiseptic, antipyretic and anti-diarrheal properties. Phytochemical studies have shown that these species are very rich in flavonoids (isoflavones) and alkaloids (quinolizidine and bipiperidyl). The aim of this study was to compare the chemical composition of both Retama species by GC/MS and LC/MS and to determinate their antimicrobial activity of two Retama species growing naturally in Algeria. Ten alkaloids and seven flavonoids were identified in cladodes of RR and RS. The quantitative analysis showed that the most abundant flavonoid of both the aqueous extract from RR and RS was the isoflavone genistein (610.0±2.8 and 408.0±14.1 mg/100 g respectively), whereas sparteine was the predominant alkaloid in RR and retamine in RS. The antibacterial activity of Retama extracts against standard strains was performed by minimum inhibitory concentration (MIC), and by the disc diffusion method (expressed by inhibition zone, IZ). Both Retama species showed the best activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), being RS aqueous extract more active than RR aqueous extract, with MIC 125 µg/mL and bactericidal activity against both strains.

Plant Growth Modulates Metabolites and Biological Activities in Retama raetam (Forssk.) Webb

“…In general, the extract from the flowering stage also showed strong activity against the same strains (diameter of inhibition zone in the range of 7 and 12 mm), while those of fresh and/or mature fruiting failed to inhibit Listeria monocytogenes , Enterococcus faecalis Vibrio vulnificus , and Vibrio cholerae . The higher activity of extracts from the vegetative and flowering stages could be ascribed to their phenolic compound richness, especially flavonoids (isoflavonoids), possibly due to their adsorption to cell membranes provoking their destabilization and/or interaction with some enzymes, substrates, or metal ion deprivation, as previously suggested [ 38 , 39 , 40 ].…”

First Occurrence of Megastigmane Glucosides in a Plant of Retama Genus

“…Since CD spectra of 1 showed a positive Cotton effect at 241 nm, C-6 was assessed to have the S absolute configuration. On the other side, the 9S absolute configuration was assigned by comparing the 13 C-NMR values of C-1', C-9, and C-10 of 1 (Table 1) with those of 9R and 9S epimers of roseoside. [35] In fact, diagnostic differences of the δ C values of this carbon set can be generally observed for 9R and 9S epimers of 9-hydroxy-megastigmane 9-Oglucopyranosides.…”

“…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.…”

Specialized Metabolites from the Allelopathic Plant Retama raetam as Potential Biopesticides

“…They have been used traditionally for the treatment of different diseases in many parts of the Mediterranean Basin, especially in North Africa and the Middle East. In fact, they showed several biological activities, including antibacterial [ 17 ], anti-inflammatory [ 18 ], antioxidant [ 19 ], anti-proliferative [ 20 ], anti-ulcer [ 19 ], anti-viral [ 21 ], and hepatoprotective activities [ 22 , 23 ].…”