A major development over the past two decades has been the realization that free radical induced lipid peroxidation and DNA damage are associated with major health problems, e.g. cancer and ageing. Plant-derived antioxidants are increasingly found beneficial in protecting against these diseases. Celtis australis L. and Celtis occidentalis L. are two plants that have a variety of uses in folk medicine but have not been evaluated before for their antioxidant and cytotoxic properties. Therefore, the extracts of both plants’ leaves were investigated for these activities, as well as isolation of the bioactive compounds responsible for the activities. Molecular structures of the compounds were elucidated by UV, HRESIMS, 1D (1H and 13C) and 2D (1H-13C HSQC and 1H-13C HMBC) NMR analyses. The ethanolic and aqueous extracts, n-butanol fractions and the isolated major compound were tested for their antioxidant activity using DPPH radical scavenging assay, xanthine oxidase-induced generation of superoxide radical and lipid peroxidation assay by thiobarbituric acid-reactive substances (TBARS) method using rat tissue homogenates. Cytotoxic activities were studied using standard MTT assay. A novel flavonoid C-triglycoside, 4‴-α-rhamnopyranosyl-2″-O-β-d-galactopyranosylvitexin, was isolated from both plants’ leaves, together with seven known flavonoids. The n-butanol fractions and the major compound 2″-O-β-galactopyranosylvitexin showed significant antioxidant activities, more pronounced than the tested standards BHT and dl-α-tocopherol in most tests. All extracts showed variable cytotoxic activities. This study provides strong evidence for the antioxidant and cytotoxic activities of the extracts of Celtis australis L. and Celtis occidentalis L. leaves, which were attributed to the polar n-butanol fractions and the major isolated flavonoid 2″-galactosylvitexin.

A chemical study of the red type of the seeds of Eragrostis tef (Zucc.) Trotter (Poaceae) led to the isolation of seven compounds from its ethanol extract, namely β-sitosterol (1), β-amyrin-3-O-(2'-acetyl(glucoside (2), β-sitosterol-3-O-β-D-glucoside (3), naringenin (4), naringenin-4'-methoxy-7-O-α-L-rhamnoside (5), eriodictyol-3',7-dimethoxy-4'-O-β-D-glucoside (6) and isorhamnetin-3-O-rhamnoglucoside (7), which are reported for the first time in the genus Eragrostis. This is the first report for the isolation of compounds (2) and (6) in nature. The isolated compounds were identified using different spectroscopic methods (EIMS, UV, ¹H NMR, ¹³C NMR, HMQC and HMBC). A proximate analysis revealed the high nutritive value of the seeds: carbohydrates (57.27%), protein (20.9%), essential amino acids (8.15%) with major leucine and lysine (1.71 and 1.35%, respectively), vitamin B₁ (1.56 mg/100 g) and potassium and calcium (32.4 and 9.63%, respectively). The seeds yielded 22% w/w of fixed oil rich in unsaturated fatty acids (72.46%), among which oleic acid, was predominant (32.41%), followed by linolenic acid (23.83%). The ethanolic extract and fixed oil of the seeds exhibited anti-hyperlipedaemic and anti-hyperglycaemic activities. Oral administration of the fixed oil for 10 days resulted in a rise in serum calcium levels in rats.

Background:Moringa peregrina is a wild plant that grown in the eastern desert mountains in Egypt. Although, this plant is native to Egypt, no details studies were traced on its chemical composition and biological activity.Materials and Methods:The different fractions of the ethanolic extract of the dried aerial parts of the plants were subjected to fractionation and purification on various silica and sephadex columns for the isolation of the major compounds which were tested for there anticancer activity. The aqueous and ethanolic extract as well as its different fractions were tested for antihyperglycemic effect on Streptozitocin-induced diabetes in rats.Results:Investigation of the different fractions of the ethanolic extract of the aerial parts of M. peregrina yielded lupeol acetate (1), β-amyrin (2), α-amyrin (3), β-sitosterol (4), β-sitosterol-3-O-glucoside (5), apigenin (6), rhamnetin (7), neochlorogenic acid (10), rhamnetin-3-O-rutinoside (12), and 6-methoxy-acacetin-8-C-β-glucoside (13) which were isolated for the first time from the plant. Compound (13) was isolated for the first time from genus Moringa. In addition, quercetin (8), chryseriol-7-O-rhamnoside (9) and quercetin-3-O-rutinoside (11) were also isolated. Identification has been established by spectral data (UV, MS, IR, 1H, 1H -1H COSY, and 13C-NMR). The major isolated compounds were found to have valuable cytotoxic activities against breast (MCF 7) and colon (HCT 116) cancer cell lines and their activities were comparable to the reference drug doxorubicin. On the other hand, the aqueous and ethanolic extracts as well as the n-hexane fraction were found to have potent antihyperglycemic effect on Streptozitocin-induced diabetes in rats.Conclusion:The Egyptian plant M. peregrina is rich in biologically active ingredients which showed potent cytotoxic activity and also its ethanolic extraxt exert a significant antihyperglycemic effect.

The antimicrobial activity of the volatile oil of Nigella sativa Linneaus seeds was studied. The antimicrobial principle has been isolated, identified as thymohydroquinone, and found to be active against gram-positive bacteria and yeasts.

No abstract