Acylated pregnane glycosides from Caralluma sinaica.

Caralluma sinaica is sold on local markets of Saudi Arabia for various health benefits however no phytochemical study has specifically been performed on this species. NMR and UHPLC-ESI-TOF-MS profilings of the ethanolic extract of the whole plant reveal a very complex phytochemical composition dominated by pregnanes. Detailed information on its constituents was obtained after isolation. Six pregnane glycosides were obtained and characterized based on the extensive spectroscopic analysis (including IR, ¹H NMR, ¹³C NMR and MS data), in addition to ten known compounds (seven pregnanes and three flavonoids). The compounds were identified as 12ß-O-benzoyl-20-O-acetyl boucerin-3-O-6-deoxy-3-O-methyl-ß-D-glucopyranosyl-(1-->4)-ß-D-cymaropyranosyl-(1-->4)-ß-D-cymaropyranoside, 12ß-O-tigloyl-20-O-acetyl boucerin-3-O-ß-D-glucopyranosyl-(1-->4)-ß-D-cymaropyranoside, 12ß-O-benzoyl-20-O-acetyl boucerin-3-O-ß-D-glucopyranosyl-(1-->4)-ß-D-digitalopyranosyl-(1-->4)-ß-D-cymaropyranosyl-(1-->4)-ß-D-cymaropyranoside, 12ß-O-benzoyl-20-O-acetyl boucerin-3-O-ß-D-glucopyranosyl-(1-->4)-hevetopyranosyl-(1-->4)-ß-D-cymaropyranosyl-(1-->4)-ß-D-cymaropyranoside, 12ß-O-benzoyl-20-O-tigloyl boucerin-3-O-ß-D-glucopyranosyl-(1-->4)-ß-D-cymaropyranoside, 12ß-20-O-dibenzoyl boucerin-3-O-ß-D-glucopyranosyl-(1-->4)-ß-D-cymaropyranosyl-(1-->4)-ß-D-cymaropyranoside. Finally, the isolated compounds were evaluated for their quinone reductase induction.

Ginger ingredients inhibit the development of diethylnitrosoamine induced premalignant phenotype in rat chemical hepatocarcinogenesis model.

To investigate the possible antitumor activity of ginger extract against hepatic carcinogenesis initiated by diethylnitrosoamines (DEN) and promoted by carbon tetrachloride (CCl(4) ). A total of 60 male Wistar albino rats were divided into four groups with 15 animals in each group. Rats in group 1 (control group) received a single intraperitoneal (i.p.) injection of normal saline. Animals in group 2 were given ginger (50 mg/kg/day) in drinking water for 8 weeks. Rats in group 3 (DEN group) were injected with a single dose of DEN (200 mg/kg, i.p.), 2 weeks later received a single dose of CCl(4) (2 mL/kg i.g) by gavage as 1:1 dilution in corn oil. Animals in group 4 (DEN-ginger group) received the same carcinogenesis induction protocol as in group 3 plus ginger (50 mg/kg/day) in drinking water for 2 weeks before induction of hepatocarcinogenesis and continued throughout the experimental period. DEN-initiated and CCl(4) -promoted hepatocarcinogenesis in male Wistar rats was manifested biochemically by elevation of serum hepatic tumor markers tested; α-fetoprotein and carcinoembryonic antigen. In addition, hepatocarcinogenesis was further confirmed by a significant increase in hepatic tissue growth factors; vascular endothelial growth factor, basic fibroblast growth factor, and hydroxyproline content. A marked decrease in endostatin and metallothonein were also observed. Long-term ginger extract administration 2 weeks before induction of hepatocarcinogenesis and throughout the experimental period prevented the decrease of the hepatic content of metallothionein and endostatin and the increase in the growth factors induced by the carcinogen. Moreover, ginger extract normalize serum hepatic tumor markers. Histopathological examination of liver tissue also correlated with the biochemical observations. These findings suggest a protective effect of ginger extract against premalignant stages of liver cancer in the DEN-initiated and CCl(4) -promoted hepatocarcinogenesis model in rats.

Osteosaponins 1 and 2: two new saponin glycosides from Osteospermum vaillantii.

Osteospermum vaillantii (Decne) T. Norl., collected from southern Saudi Arabia, yielded two new saponins characterised as 3-O-beta-D-glucopyranosyl-(2' --> 1'')-beta-D-glucopyranosyl-(3' --> 1''')-O-beta-D-galactopyranosyl-oleanolic acid, designated as osteosaponin, and 3-O-beta-D-glucopyranosyl-(2' --> 1'')-beta-D-glucopyranosyl-(2''-1''''')-beta-D-glucopyranosyl-(3' --> 1''')-O-beta-(-D-galactopyranosyl-oleanolic-acid-28-C(O)-O-beta-D-(1'''')-glucopyranosyl ester, designated as osteosaponin. The sugar attachments and configurations were confirmed by spectroscopic methods, that is, 1H, 13C-NMR, COSY, HSQC and HMBC-NMR experiments.

Phytochemical and biological studies on Saudi Commiphora opobalsamum L.

The aerial part of Commiphora opobalsamum L. (Burseraceae) growing in Saudi Arabia was subjected to a phytopharmacological investigation in order to identify its major chemical constituents and to evaluate its extracts and isolated compounds in preliminary in vitro assays for antimicrobial, antimalarial, antitumor, anti-inflammatory (COX-2 inhibition), antioxidant and estrogenic activity. Six compounds were isolated and identified as the triterpenes friedelin, canophyllal, and oleanonic acid; the flavonols mearnsetin and quercetin; and syringic acid. The ethyl acetate extract was moderately active against Staphylococcus aureus, Pseudomonas aeruginosa, and Plasmodium falciparum; while the petroleum ether and chloroform extracts inhibited COX-2 at 5 and 10 microg mL(-1), respectively. Of the isolated compounds, syringic acid showed moderate antimalarial, anticandidal, and antimycobacterial activity; while mearnsetin and quercetin exhibited antioxidant activity comparable to ascorbic acid and trolox. This is the first detailed phytochemical investigation of C. opobalsamum L. growing in Saudi Arabia and elsewhere. The isolated compounds are reported from this plant for the first time and their full (1)H and (13)C NMR assignments are included.

Three new diterpenes and the biological activity of different extracts of Jasonia montana.

Three new diterpenes, namely jasonin-a (1), jasonin-b (2), and jasonin-c (3) were isolated from the aerial parts of Jasonia montana (Asteraceae). Their structures were elucidated on the basis of spectral data as [(1E)-2-((2S)-1,2,5-trimethylbicyclo[3.2.l]octan-8-yl)vinyl] benzene-3-carboxylic acid (1), [3-((2S, 5S)-1,2, 5-trimethylcycloheptanyl)propyl]benzene-3-carboxylic acid (2), and [(1E)-3-((7R)-1,7-dimethy-4-methylenecycloheptanyl)prop-1-enyl] benzene-3-carboxylic acid (3). In addition, the previously reported 5,7,3'-trihydroxy-3,6,4'-trimethoxy flavone designated as centaureidin (4), was also isolated and characterized from this source. The different extracts of the plant were also screened for hypoglycemic, antidiabetic, and antimicrobial activities, wherein the petroleum ether and ethanolic extracts exhibited hypoglycemic and antidiabetic activity, and the petroleum ether and chloroform extracts showed antimicrobial activity.

Three new and two rare furanoeremophilanes from Senecio asirensis.

Three new furanoeremophilanes have been obtained from the aerial parts of Senecio asirensis (N. O. Asteraceae), and characterized as 6-hydroxylmethyl-9-methoxyl-4,11-dimethylnaphtho[2,3-b]furan, designated asirensane-a (1), 6-hydroxyl-1,2-dimethoxyl-4,6,11-trimethyl-6-hydronaphtho[2,3-a]furan-7-one, named asirensane-b (2), and (6,12-dihydroxyl-9-methoxyl-4-methyl-11-acetyl-3,4-dihydronaphtho[2,3-b]furan- 3-yl)methyl (2'Z)-2'-methyl-but-2'-enoate, designated asirensane-c (3). In addition, two rare furanoeremophilanes have also been isolated and characterized from this source, namely 9-methoxyl-4,11-dimethylnaphtho[2,3-b]furan, named 14-nordehydro-calohastine (4), and 4,11-dimethylnaphtho[2,3-b]furan-6,9-dione, designated as maturinone (5). Their structures have been elucidated on the basis of spectral analysis. The alcoholic extract was also tested for anti-inflammatory activity, which decreased edema by 22% at a dose of 500 mg kg-1 after 3 h with respect to the control group treated only with carrageenan, while the standard drug phenylbutazone showed a 50% decrease at a dose of 100 mg kg-1, indicating that the extract has moderate anti-inflammatory activity.

Verbenacine and salvinine: two new diterpenes from Salvia verbenaca.

Two new diterpenes namely verbenacine (1) and salvinine (2) have been isolated from the aerial parts of Salvia verbenaca. Their structures have been elucidated on the basis of chemical and spectral data as 3alpha-hydroxy-19-carboxykaur-15-ene and 19-hydroxy-12,14-dioxo labda-15,17-diene.

Antihepatotoxic activity of seeds of Cichorium intybus.

The different fractions of alcoholic extract and one phenolic compound AB-IV of seeds of Cichorium intybus Linn were screened for antihepatotoxic activity on carbon tetrachloride (CCl(4))-induced liver damage in albino rats. The degree of protection was measured using biochemical parameters like aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALKP), and total protein (TP). The methanol fraction and compound AB-IV were found to possess a potent antihepatotoxic activity comparable to the standard drug Silymarin (Silybon-70). The histopathological study of the liver was also carried out, wherein the methanolic fraction and compound AB-IV showed almost complete normalization of the tissues as neither fatty accumulation nor necrosis was observed.

Alkaloids of Thalictrum angustifolium.

Fractionation and chromatography of the ethanolic extract of the roots of Thalictrum angustifolium L. (Ranunculaceae) afforded five alkaloids: noroxyhydrastinine (1), O-methylthalicberine (2), berberine iodide (3), jatrorrhizine iodide (4), magnoflorine iodide (5). In addition, one simple aromatic compound, methyl-4-hydroxybenzoate (6), was also isolated. These compounds were identified via comparison of their spectral data with authentic compounds or spectra available within our laboratory. This is the first reported isolation of these compounds from this species.