GC/MS analysis and characterization of 2-Hexadecen-1-ol and beta sitosterol from Schimpera arabica extract for its bioactive potential as antioxidant and antimicrobial.

AIMS: We evaluated the in vitro antioxidant and antimicrobial potential of Schimpera arabica extract and fractions (2-Hexadecen-1-ol and beta sitosterol). METHODS AND RESULTS: Free radical scavenging activity was estimated by using ABTS and DPPH methods, reducing power and iron chelation was studied to investigate antioxidant potential of the extracts. Well-diffusion method was utilized to evaluate the antimicrobial activity of the extracts. Gas chromatography-mass spectroscopy analysis of the extract revealed the presence of 27 compounds. Phenolic and flavonoid contents were found in high amount (7·6-18 mg GAE, mg g-1 ; 3·2-10·8 mg catechin, mg g-1 ) in dry plant material. CONCLUSIONS: Among all the extracts, 2-Hexadecen-1-ol and beta sitosterol were the major constituents of crude extract and exhibited significant antioxidant potential as well antimicrobial activity; however, all other fractions also exhibited fare degree of antioxidant potential. 93% DPPH was scavenged by 100 µg ml-1 of the ethyl acetate fraction; in ABTS assay chelation was 86·2 and 88% in ferric chloride reducing power assay. SIGNIFICANCE AND IMPACT OF THE STUDY: Schimpera arabica is naturally present and used in food preparation in most Arabian nations. The characterization of S. arabica would provide an insight into its medicinal use as home remedial for bacterial infection and as antioxidant. Significant and comparable antimicrobial activity was demonstrated by both 2-Hexadecen-1-ol and beta sitosterol fractions. The results suggest that S. arabica contain a good amount of natural antioxidants of medicinal importance. However, further investigations are needed to characterize the further activity of 2-Hexadecen-1-ol and beta sitosterol in vivo.

Isolation and NMR spectra of syringaresinol-beta-D-glucoside from Cressa cretica.

The isolation, (1)H-NMR and revised (13)C-NMR assignments of syringaresinol-beta-D-glucoside from Cressa cretica are reported.

Chemical and biological investigations on Zizyphus spina-christi L.

Different extracts and fractions of the leaves, fruits and seeds of Zizyphus spina-christi L. grown in Egypt were investigated in vitro for their antiviral, antifungal and antibacterial activities. The flavonoids quercetin, hyperoside, rutin and quercetin-3-O-[beta-xylosyl-(1-2)-alpha-rhamnoside] 4'-O-alpha- rhamnoside) were isolated.

Biological screening of selected medicinal Panamanian plants by radioligand-binding techniques.

Nineteen plants from the Republic of Panama were selected by their traditional uses in the treatment of hypertension, cardiovascular, mental and feeding disorders and 149 extracts were screened using radioligand-receptor-binding assays. The methanol:dicloromethane extracts of the bark and leaves of Anacardium occidentale L., the leaves of Begonia urophylla Hook., the roots of Bocconia frutescens L., the stems and leaves of Cecropia cf.obtusifolia Bertol., the branches of Clusia coclensis Standl., the bark of Cochlospermum vitifolium (Willd.)Spreng., the roots of Dimerocostus strobilaceus Kuntze, the bark of Guazuma ulmifolia Lam., the leaves of Persea americana Mill. and the branches of Witheringia solanaceae L'Her. inhibited the [3H]-AT II binding (angiotensin II AT1 receptor) more than 50%. Only extracts of the roots of Dimerocostus strobilaceus Kuntze and the stems of Psychotria elata (Sw.) Hammel were potent inhibitors of the [3H] NPY binding (neuropeptide Y Y1 receptor) more than 50% and the ethanolic extracts of the leaves of Cecropia cf. obtusifolia Bertol., the leaves of Hedyosmum bonplandianum H.B.K., the roots of Bocconia frutescens L., the stem of Cecropia cf. obtusifolia Bertol. and the branches of Psychotria elata (Sw.) Hammel showed high inhibition of the [3H] BQ-123 binding (endothelin-1 ET(A) receptor) in a preliminary screening. These results promote the further investigation of these plants using the same assays.

Isolation and complete NMR assignment of the numbing principle from Chrysanthemum morifolium.

The isolation and the complete 1H and 13C-NMR assignments of the numbing principle [N-isobutyl-6-(2-thienyl)-2E,4E-hexadienamide (1)] from Chrysanthemum morifolium are reported.

A new acylated flavonol triglycoside from Carrichtera annua.

A new acylated flavonol triglycoside, quercetin 3-O-[(6-feruloyl-beta-glucopyranosyl)-(1-->2)-beta-arabinopyran oside] -7-O-beta-glucopyranoside (1), as well as the known flavonoid quercetin, were isolated from the whole plants of Carrichtera annua. The structure of 1 was established by UV, MS, and 1D and 2D NMR spectroscopy, including DEPT, DQF-COSY, TOCSY, HSQC, HSQC-TOCSY, and HMBC experiments.

Anti-HIV activity of flavonoids and proanthocyanidins from Crataegus sinaica.

In addition to quercetin, hyperoside, rutin, vitexin, 2″-O-rhamnosylvitexin, (4″'-O-acetyl)-2″-O-rhamno-sylvitexin, epicatechin, procyanidin B-5, proanthocyanidin A-2, procyanidin B-2 and procyanidin C-1, which were reported before in Crataegus sinaica (Rosaceae), three more flavonoids were isolated from the same plant, i.e. (+)-taxifolin, 3-O-ß-arabinopyranosyl-(+)-taxifolin and 3-0-ß-xylopyranosyl-(+)-taxifolin. The in vitro anti-HIV activity of some selected flavonoids and proanthocyanidins was evaluated. The dimeric procyanidin B2 and proanthocyanidin A2, and especially the trimeric procyanidin C1 showed some in vitro anti-HIV activity.

Anti-complementary activity of Crataegus sinaica.

The 80% and 70% acetone extracts from fruits and leaves of Crataegus sinaica Boiss (Rosaceae) and the ethyl acetate-, butanol-, and water-fractions obtained from these initial extracts as well as the isolated compounds, quercetin (1) (1), hyperoside (quercetin 3-O-galactoside) (2) (2), rutin (quercetin 3-O-rutinoside) (3) (2), vitexin (4) (1), rhamnosylvitexin (5) (3), monoacetylrhamnosylvitexin (6) (3), epicatechin (7) (4), procyanidin B-5 (8) (4), proanthocyanidin A-2 (9) (5), procyanidin B-2 (10) (4), and procyanidin C-1 (11) (4), were tested for their influence on the classical (CP) and alternative (AP) pathways of complement-mediated hemolysis. All extracts and fractions showed a strong anti-complementary effect in a dose-dependent way which was more pronounced on the CP than on the AP. The results indicated that the pure proanthocyanidins were active on the CP. Procyanidin C-1 and proanthocyanidin A-2 were the most active on the CP and also showed activity on AP, whereas the flavonoids isolated were generally less active. However, rutin, showed a strong activity, quercetin and rhamnosylvitexin a moderate activity on the CP. This is the first report on the chemical constituents and complement-modulating activity of C. sinaica and on the occurrence of proanthocyanidin A-2 (9) in hawthorn.

Specific gravity measurements of lamb carcass joints.

10 Ossimi lamb carcasses were used to determine the specific gravity values of different joint cuts. The correlation coefficients were established between the specific gravities of these joints and the percentages of fat and muscle in the rib saddle joint. It was found that the gravity of different carcass sections was significantly related to the muscle and fat percentages in the rib saddle joint. The results indicate that the specific gravity values of carcass sections can be utilized for a practical estimate and assessment of carcass components.

The effect of daylength and level of feeding on serum prolactin in growing lambs.

Twenty-four castrated male lambs initially maintained on a photoperiod of 12 h light:12 h dark were allocated to a factorial experiment with two daylengths (8 h L: 16 h D or 16 h L: 8 h D) and two levels of feeding (restricted or ad libitum). Blood samples were taken every 4 h for 24 h during the introductory period and after 24, 51 and 79 days of treatment. There were highly significant positive effects of daylength and level of feeding on serum prolactin: mean concentrations increased from a mean of 38 plus or minus 1 ng/ml during the introductory period until at day 79 they were: 8L: 16D (restricted diet), 81 ng/ml; (food ad libitum), 167 ng/ml; 16L:8D (restricted diet), 262 ng/ml; (food ad libitum), 262 ng/ml (S.E. of treatment mean plus or minus 4). Long daylength and feeding ad libitum also significantly increased growth rate.