Découverte de Centaurea hyalolepis Boiss. (Asteraceae) dans la région de Djelfa (Algérie)

Discovery of Centaurea hyalolepis Boiss. (Asteraceae) in the region of Djelfa (Algeria).Mots clés: Asteraceae, Centaurea hyalolepis, découverte, Djelfa.Key words: Asteraceae, Centaurea hyalolepis, discovery, Djelfa.

Compositional study, antibacterial and antioxidant potential of Lepidium draba L. (brascicaceae)

The present study was designed to evaluate the phytochemical screening, antimicrobial and antioxidant activities of Lepidium draba The arial parts of Lepidium draba showed the presence of alkaloids, terpenoids, tannins,saponins, Leuco anthocyans, triterpenoids and flavonoids. Three known flavonoid glycosides: rhamnocitrin- 3-O- Dglucoside (1), complanatuside (2), genkwanin- 4’-O- Dglucoside (3) were isolated from the all parts of Lepidium draba their structures were elucidated by NMR experiments and acid hydrolysis. The antibacterial activity of the extracts was evaluated by disc diffusion assay and the antioxidant activity and phenolic contents of n-butanol extract were evaluated in vitro using spectrophotometer methods.Peer Reviewe

Phytochemical investigation of Volutaria lippii and evaluation of the antioxidant activity

Volutaria lippii (L.) Cass. ex Maire, syn. Centaurea lippii (L.), (Asteraceae) is a plant from the central region of Algeria, considerably distributed in all Mediterranean areas. Herein, the antioxidant activity of the three derived fractions [chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH)] of the 70% methanol extract of the aerial parts (leaves and flowers), was assessed by using CUPRAC, ABTS, DPPH free radical scavenging, and beta-carotene bleaching methods. The results obtained allowed to guide the fractionation of EtOAc and n-BuOH fractions by CC followed by purification by TLC and reverse phase HPLC. A guaianolide glucoside, 3 beta-hydroxy-11 beta,13-dihydrodehydrocostuslactone 8 alpha-O-(6'-acetyl-beta-glucopyranoside) (1), never reported in the literature, was isolated together with other known compounds (2-14). Their structures were elucidated by the extensive use of 1 D- and 2 D-NMR experiments along with ESI-MS analyses and with comparison with literature data

A flavonoid with high antioxidant effect from Centaurea acaulis L.

The flavonoid glycosides: patuletin 7-O-β-glucopyranoside 3, hispidulin 7-O-β-glucopyranoside 2 together with hispidulin 1, were isolated from the n-butanol soluble part of the aqueous-MeOH extract of the flowering aerial parts of C. acaulis L. (Asteraceae), an endemic species of Algeria and Tunisia. The structures were established by chemical and spectral analysis, mainly HR-ESIMS, UV and NMR experiments (COSY, NOESY, HSQC and HMBC). Patuletin 7-O-β-glucopyranoside showed a high antioxidant effect, especially scavenging of DPPH (IC50 = 4.83 µg/ml) anions and inhibition of lipid peroxidation (51.93%.). Those various antioxidant activities were compared to vitamin C (standard antioxidant)

First Occurrence of Megastigmane Glucosides in a Plant of Retama Genus

Chemical investigation of Retama sphaerocarpa collected in Algeria resulted in the isolation of two megastigmane glucosides, compounds 1 and 2, along with a series of isoflavones and phenol derivatives. Compound 1, named retamoside, was new and its structure was determined by extensive application of spectroscopic methods, including HRMS, 1D and 2D NMR and CD. The anti-inflammatory properties of co-occurring main megastigmane, saurobaccioside B (2) and structurally related vomifoliol (3) on LPS-stimulated murine macrophages RAW 274.7 have been evaluated

Maroccanin: A New g -lactone and Other Constituents from Centaurea maroccana Ball. (Asteraceae)

A new g -lactone named maroccanin (1) together with 5 known compounds : scopoletin (2); 8 a -[2’-hydroxymethyl-2’-butenoyloxy]-dehydromelitensin (3); 11,13-dehydromelitensin (4); 8 a -[2’-hydroxymethyl-2’-butenoyloxy]-sonchucarpolide (5) and 5Hα,6Hβ,7Hα,-15-hydroxy-8α-( 1’,2’-dihydroxyethyl-acryloxy)-elema-1(2),3(4),11(13)-trien-6,12-olide (6), were isolated from the chloroform soluble part of the aqueous-MeOH extract of the flowering aerial parts of C.maroccana Ball. (Asteraceae), an endemic species of the North of the Sahara. The structures were established by chemical and spectral analysis, mainly HR-ESIMS, HREIMS,UV and NMR experiments (COSY, NOESY, HSQC and HMBC). The compounds 3 and 5 are new for the genus Centaurea

Maroccanin: A new γ-lactone and other constituents from Centaurea maroccana ball. (Asteraceae)

A new γ-lactone named maroccanin (1) together with 5 known compounds : scopoletin (2); 8α-[2’- hydroxymethyl-2’-butenoyloxy]-dehydromelitensin (3); 11,13-dehydromelitensin (4); 8α-[2’-hydroxymethyl-2’- butenoyloxy]-sonchucarpolide (5) and 5Hα,6Hβ,7Hα,-15-hydroxy-8α-(1’,2’-dihydroxyethyl-acryloxy)-elema1(2),3(4),11(13)-trien-6,12-olide (6), were isolated from the chloroform soluble part of the aqueous-MeOH extract of the flowering aerial parts of C. maroccana Ball. (Asteraceae), an endemic species of the North of the Sahara. The structures were established by chemical and spectral analysis, mainly HR-ESIMS, HREIMS,UV and NMR experiments (COSY, NOESY, HSQC and HMBC). The compounds 3 and 5 are new for the genus Centaurea.This work was supported by Algerian FNR program (PNR 8u250/4211, ATRST contract 26/70) and by the NATO Science project (Valorisation of Phytochemical Natural Resources in Algeria)