No abstract

The present work concerns the anti-inflammatory activity of chemical constituents isolated from the roots of Echinops gracilis. The anti-inflammatory activity of the ethyl acetate extract as well as compounds 1, 2, and 3 were evaluated using inhibition of protein denaturation and antiproteinase methods. Structural elucidation was achieved through analysis of NMR spectra (1H and 13C, 1H1H COSY, HSQC, HMBC) and literature survey. Seven compounds were identified as erythrinasinate (1), vogelate (2), ferulic acid (3), p-coumaric acid (4), ursolic acid (5), oleanolic acid (6), and quercetin (7). All the isolated compounds were reported for the first time from this plant. Ethyl acetate extract showed potent inhibitory activity against protein denaturation (IC50 = 125.54 µg/mL). Erythrinasinate (1) and vogelate (2) showed a significant anti-inflammatory activity with an IC50 value of 469.43 and 413.71 µg/mL, respectively. The results obtained from the ethyl acetate extract can justify the use of E. gracilis roots in traditional medicine for the treatment of rheumatism.

Phytochemical investigation of the crude methanolic extract of the leaves of Tapinanthus pentagonia (Loranthaceae) resulted in the isolation of four known flavonoids namely, quercetin 4’-methylether (1), 4’-methoxy-3’,5,7-trihydroxyflavone (2), quercetin-3-O-rhamnoside (3) and quercetin 3-O-rhamnoside4’- methylether (4). The structures of the isolated compounds were elucidated based on their 1D and 2D-NMR data. This is the first phytochemical study of that plant. The DPPH(2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ABTS scavenging activity and ferric reducing antioxidant power (FRAP) were used to assess the antioxidant activities of the crude extract and three of the isolated compounds using catechin, ascorbic acid and gallic acid as standards, respectively. Results of the findings revealed that compound 3 exhibited the highest antioxidant activity in the three tests based on its IC50values followed by compound 4. Its IC50 value was 0.024 mg/ml comparable to that of catechin (0.015 mg/ml) for the radical scavenging activity. In summary, compounds 1, 3 and 4 exhibited good antioxidant properties and reducing power compared to the crude methanolic extract.

Mortality due to microbial diseases continues to be a major problem in many developing countries. The present study aims to evaluate the antibacterial and antioxidant activities of the ethyl acetate extract and some isolated compounds from aerial parts of Echinops gracilis. The phytochemical study resulted in the isolation of a new flavonoid derivative named apigenin-7- O-(4″-feruloyl)-β-D-glucoside (1), together with 2 known compounds: apigenin -7-O-(4″-trans- p-hydroxycinnamoyl) -β-D-glucoside (2), and apigenin -7-O-glucoside (3). Their chemical structures were determined using a combination of NMR and IR spectroscopic and MS techniques, as well as by comparison with literature data. The extract and isolates were evaluated for their antibacterial and antioxydant properties. The EtOAc extract and compounds 1 and 2 showed the ability to scavenge 2,2′-zino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS) with scavenging concentration (SC50) values of 13.6 ± 0.8 µg/mL, 108.2 ± 4.3 µg/mL, and 28.5 ± 2.2 µg/mL, respectively. In addition, compound 1 displayed significant activity against Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia, with minimum inhibition concentration (MIC) values of 31.2, 15.6, and 31.2 µg/mL respectively.