A possible general mechanism for ultrasound-assisted extraction (UAE) suggested from the results of UAE of chlorogenic acid from Cynara scolymus L. (artichoke) leaves

The use of ultrasound-assisted extraction (UAE) for the extraction of chlorogenic acid (CA) from Cynara scolymus L., (artichoke) leaves using 80% methanol at room temperature over 15 min gave a significant increase in yield (up to a 50%) compared with maceration at room temperature and close to that obtained by boiling over the same time period. A note of caution is introduced when comparing UAE with Soxhlet extraction because, in the latter case, the liquid entering the Soxhlet extractor is more concentrated in methanol (nearly 100%) that the solvent in the reservoir (80% methanol) due to fractionation during distillation. The mechanism of UAE is discussed in terms of the effects of cavitation on the swelling index, solvent diffusion and the removal of a stagnant layer of solvent surrounding the plant material.

Water soluble polysaccharides extracted from Pterocladia capillacea and Dictyopteris membranacea and their biological activities

Cold and hot water extracts (CWE, HWE) of both the red alga Pterocladia capillacea (P. capillacea) and the brown alga Dictyopteris membranacea (D. membranacea) were studied for their polysaccharide contents. In both (CWE) and (HWE) extracts. Relatively higher yields were obtained in case of P. capillacea pillacea (2.87 and 6.46%, respectively). The polysaccharide contents of the CWE hydrolyzate of both studied algae analyzed by HPLC were found to be enriched with glucuronic acid, arabinose and glucose, whereas, HWE hydrolyzate were found to be rich in glucuronic acid and fructose. The polysaccharide contents of the CWE and HWE extracts of (D. membranacea) showed appreciable antimicrobial activity in addition to a moderate antitumor activity against HELA (Cervix carcinoma cell line) at IC50 = 9.83 μg/dl, respectively. Whereas the polysaccharide contents of the CWE and HWE extracts of (P. capillacea) exhibited a promising anticoagulant activity.

Flavonoids, anti-inflammatory activity and cytotoxicity of Macfadyena unguis-cati L

Ethyl acetate and ethanol extracts of unflowering aerial part of Macfadyena unguis-cati L. (Fam. Bignoniaceae) were found to be rich in phenolic compounds. From ethyl acetate extract, six flavonoids were identified, 8, methoxy, acacetin, 7-O glucoside; 6, methoxy apigenin 7-O glucoside; 4'-O methyl scutellarin, 6-O apiosyl galactoside; acacetin, 7-O glucosyl, 8-C rhamnosyl, 3-O-alpha arabinofuranoside; 4'-methyl, 6- methoxy kaempferol, 7-O, 8-C diglucoside and vicenin II were isolated, while 6, methoxy, acacetin 7-O glucoside; and quercitrin were isolated from ethanol extract. These compounds were characterized and identified by their physicochemical and spectral data. The crude ethanol extract exhibited significant anti-inflammatory activity (80.47%) and moderate cytotoxic activity against lung cell line.

Polyphenols of Melaleuca quinquenervia leaves--pharmacological studies of grandinin

Four polyphenolic acid derivatives and three ellagitannins were isolated from the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake for the first time. Their structures were elucidated as gallic acid (1), ellagic acid (2), 3-O-methylellagic acid (3), 3,4,3'-tri-O-methylellagic acid (4), 2,3-O-hexahydroxydiphenoyl-(alpha/beta)-D-(4)C(1)-glucopyranose (5), castalin (6) and grandinin (7) on the basis of chemical, mass spectrometric (-ve ESI-MS) and spectroscopic (UV, (1)H-, (13)C NMR, (1)H,(1)H-, (1)H,(13)C-COSY, (1)H,(1)H-TOCSY and HMBC) analyses. Grandinin (the major compound) showed radical scavenging properties by its reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical [EC(50) = 4.3 +/- 0.3 micro g mL(-1)]. It was found to be relatively nontoxic in mice [LD(50) = 316 mg Kg(-1) b.wt.]. It exhibited a significant dose-dependent (35-70 mg Kg(-1)) hypoglycemic effect by significantly reducing blood glucose level in basal condition and after heavy glucose load in normal mice. Moreover, it reduced the elevated blood glucose level in STZ-induced diabetic mice. In addition, grandinin reduced the elevated blood urea nitrogen and serum lipid peroxides in STZ-induced diabetic mice.

Phytochemical and pharmacological studies on Sideritis taurica Stephan ex Wild

Fatty acids (FA), hydrocarbons, alpha-amyrin, stigmasterol and beta-sitosterol were identified in the n-hexane extract of the aerial parts of Sideritis taurica Stephan ex Wild. Xanthotoxin, as well as 2-acetyl-3-hydroxy-5,6,8-trimethoxy-1,4-naphthoquinone were isolated from the methylene chloride extract of the plant. In addition to apigenin 7-O-beta-D-glucopyranoside and apigenin, previously reported from the plant, hypolaetin 7-O-beta-D-allopyranosyl-O-beta-D-glucopyranoside was isolated from the ethyl acetate extract. From the methanol extract, isoscutellarein 7-O-beta-D-allopyranosyl-O-beta-D-glucopyranoside was also isolated. Toxicity study of petroleum ether extract (f(1)), ethanolic extract (f(2)), dichloromethane fraction of f(2) (f(3)) and n-butanolic fraction of f(2) (f(4)) of the plant proved that it is relatively nontoxic. The tested extracts and fractions exhibited significant analgesic, anti-inflammatory, anti-ulcerogenic and antihyperglycaemic activities, but no anticonvulsant and antipyretic effects, as compared with control groups and reference drugs.

Iridoids from Phlomis aurea Decne growing in Egypt

A new iridoid gentiobioside (4, assigned the name phlomiside) was isolated from the leaves of Phlomis aurea growing in Egypt, in addition to auroside (1), lamiide (2), 8-epi-loganin (3), forsythoside B (5), quercetin-3-O-beta-D-glucopyranoside (6) and kaempferol-3-O-beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranoside (7). Structures of these compounds were elucidated by conventional methods of analysis as well as by different spectroscopic techniques.

Flavonoids of Melaleuca quinquenervia

From the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake, the new flavonoid 5,7,3',4'-tetrahydroxyflavone 2'-O-beta-D-glucopyranuronide, as well as eight known flavonol glycosides have been isolated and characterized. The structures were established by chromatography, chemical degradation and UV spectroscopy and confirmed by ESI-MS and NMR spectroscopy. This is the first report on the isolation and identification of these flavonoids in the genus Melaleuca.

Bioactivity studies of Salvia transsylvanica (Schur ex Griseb) grown in Egypt

Some pharmacological effects of the ethanol extract of Salvia transsylvanica (Schur ex Griseb) were experimentally investigated. The tested extract of the plant proved to be relatively nontoxic (LD50 = 4.437 g/kg b.wt.). The extract induced significant analgesic, antipyretic, antiepileptic, antiinflammatory, antiulcerogenic, as well as tranquillizing activities, besides increasing the bleeding time and exhibiting no central skeletal muscle relaxant effect compared with control groups and standard drugs.

The essential oil of olibanum

The essential oil of the oleogum resin "Olibanum" was prepared by direct steam distillation as well as by steam distillation of an N-hexane extract. Physical and chemical constants of the oil were determined. GC-MS was used for the analysis of the oil. Thirty-three components were identified in the steam distilled oil by their Kováts indices on stabilized OV-1 columns and by mass spectral data. The oil contains 62.1% esters, 15.4% alcohols, 9.9% monoterpene hydrocarbons, and 7.1% diterpenes. Certain minor constituents of the steam distilled oil failed to show up in the oil prepared by steam distillation of the N-hexane extract. Both oils exhibit antimicrobial activity, the activity of the steam distilled oil being higher than that of the oil prepared by steam distillation of the N-hexane extract.