Fathalla M. Harraz

Chemical composition, insecticidal and insect repellent activity of Schinus molle L. leaf and fruit essential oils against Trogoderma granarium and Tribolium castaneum.

Fruit and leaf essential oils of Schinus molle showed insect repellent and insecticidal activity against Trogoderma granarium and Tribolium castaneum. In these oils, 65 components were identified by GC-MS analysis. Hydrocarbons dominated the oil composition with monoterpenes occurring in the largest amounts in fruits and leaves, 80.43 and 74.84%, respectively. p-Cymene was identified as a major component in both oils. The high yield and efficacy of S. molle essential oil against T. granarium and T. castaneum suggest that it may provide leads for active insecticidal agents.

Acylated pregnane glycosides from Caralluma tuberculata and their antiparasitic activity.

Five pregnane glycosides were isolated from Caralluma tuberculata (1-5), in addition to a known one (russelioside E, 6). The structures of the isolated compounds were elucidated by the analysis of NMR data and FAB-MS experiments. All the isolated compounds were tested for their antimalarial and antitrypanosomal activities as well as their cytotoxicity against human diploid embryonic cell line (MRC5).

Cycloartane triterpene glycosides from Egyptian Astragalus species.

Abstract Tomentoside I, a new tetranor-cycloartane triterpene glycoside was isolated fromAstragalus tomentosus. Its structure was established as 6α-acetoxy-23-ethoxy-16β,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3β-O-xyloside, on the basis of spectral evidence. 3-O-Methyl-chiro-inositol ether was also isolated and identified. The known compound, astragaloside II, previously isolated fromA. spinosus, was also identified.

Antihyperglycaemic and hypolipidaemic effects of the methanolic extract of Caralluma tuberculata in streptozotocin-induced diabetic rats

The antihyperglycaemic and hypolipidaemic effects of the methanolic extract of Caralluma tuberculata were investigated in streptozotocin (STZ)-induced diabetic rats. The antihyperglycaemic activity was assessed by the reduction in fasting blood glucose (54% at 4th week) and the peak of blood glucose at 120 min of an oral glucose tolerance test in diabetic rats. Further, the tested extract also increased plasma insulin by 206.8%. The hypolipidaemic action of the extract was evident by the significant decrease in the levels of total cholesterol, triglycerides and LDL-cholesterol by 41.5%, 36.7% and 49.1%, respectively, compared to diabetic rat values. Interestingly, the extract increased the cardio-protective lipid HDL-cholesterol by 147.97% as compared to diabetic rat value. The present data suggests that the methanolic extract of C. tuberculata has both antihyperglycaemic and hypolipidaemic effects in STZ-induced diabetic rats that may need further studies to be used in the management of diabetes and associated hyperlipedaemia.

Chemical constituents from Tribulus terrestris and screening of their antioxidant activity

Two oligosaccharides (1,2) and a stereoisomer of di-p-coumaroylquinic acid (3) were isolated from the aerial parts of Tribulus terrestris along with five known compounds (4-8). The structures of the compounds were established as O-β-D-fructofuranosyl-(2→6)-α-D-glucopyranosyl-(1→6)-β-D-fructofuranosyl-(2→6)-β-D-fructofuranosyl-(2→1)-α-D-glucopyranosyl-(6→2)-β-D-fructofuranoside (1), O-α-D-glucopyranosyl-(1→4)-α-D-glucopyranosyl-(1→4)-α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside (2), 4,5-di-p-cis-coumaroylquinic acid (3) by different spectroscopic methods including 1D NMR ((1)H, (13)C and DEPT) and 2D NMR (COSY, TOCSY, HMQC and HMBC) experiments as well as ESI-MS analysis. This is the first report for the complete NMR spectral data of the known 4,5-di-p-trans-coumaroylquinic acid (4). The antioxidant activity represented as DPPH free radical scavenging activity was investigated revealing that the di-p-coumaroylquinic acid derivatives possess potent antioxidant activity so considered the major constituents contributing to the antioxidant effect of the plant.

Acylated flavonoids from Blepharis ciliaris

Abstract From the ethanolic extract of aerial parts of Blepharis ciliaris one novel flavone, apigenin 7-(3″-acetyl-6″- E - p -coumaroylglucoside), and one novel flavanone, naringenin 7-(3″-acetyl-6″- E - p -coumaroylglucoside), were isolated. Their structures were elucidated mostly based on electrospray mass spectrometry and homo- and hetero-nuclear two-dimensional NMR techniques. No flavonoid has previously been identified with aliphatic and aromatic acyl groups on the same monosaccharide in the 3- and 6-positions, respectively.

Chemical composition, antimicrobial and insecticidal activities of the essential oils of Conyza linifolia and Chenopodium ambrosioides

Two essential oil-containing plants growing wildly in Egypt: Conyza linifolia (Willd.) Täckh. (Asteraceae) and Chenopodium ambrosioides L. (Chenopodiaceae) were subjected to essential oil analysis and biological investigation. The essential oils from both plants were prepared by hydrodistillation, and GC/MS was employed for volatiles profiling. This study is the first to perform GC/MS analysis of C. linifolia essential oil growing in Egypt. C. linifolia essential oil contained mainly sesquiterpenes, while that of C. ambrosioides was rich in monoterpenes. Ascaridole, previously identified as the major component of the latter, was found at much lower levels. In addition, the oils were investigated for their antimicrobial activity against two Gram positive and two Gram negative bacteria, and one fungus. The insecticidal activities of both oils, including mosquitocidal and pesticidal potentials, were also evaluated. The results of biological activities encourage further investigation of the two oils as antimicrobial and insecticidal agents of natural origin.

Iridoid glycosides from Barleria trispinosa.

A new iridoid glycoside and three known iridoid glycosides were isolated from the aerial parts of Barleria trispinosa. The structure of the new compound was determined as 6-α-L-rhamnopyranosyl-8-O-acetylshanzihiside methyl ester. The known compounds were identified as 6,8-O,O-diacetylshanhiside methyl ester (acetyl barlerin), 8-O-acetylshanzhiside methyl ester (barlerin) and shanzhiside methyl ester, which were isolated from the plant for the first time. The structures of the isolated compounds were elucidated by spectroscopic evidence, mainly one- and two-dimensional proton and carbon-13 NMR spectroscopy.

Hypnocretenolide derivatives from Hedypnois cretica

Abstract The aerial parts of Hedypnois cretica afforded four sesquiterpene lactones all closely related to hypnocretenolide. Two lactones were glucopyranosi

Volatiles profiling and bioactivities of Cupressus spp. leaf and cone essential oils as analyzed via chemometrics tools

ABSTRACT Cupressus is a genus of considerable medicinal value worldwide. The present work aims at assessing essential oil compositional differences within Cupressus in the context of its different genotypes and organs. Volatiles profiling was determined via gas chromatography-mass spectrometry coupled to chemometrics. A total of 75 volatile components were identified. Monoterpene hydrocarbons amounted for the major volatile class, with α-pinene and 3-carene most abundant in Cupressus sempervirens versus sabinene and terpinen-4-ol in Cupressus macrocarpa. Multivariate data analyses revealed that α-pinene, sabinene, terpinen-4-ol and 3-carene are the most significant for species classification. The five examined essential oils exhibited potential insecticidal and anticholinesterase effects, with C. sempervirens var. pyramidalis cone oil being the most potent for acetylcholinesterase inhibitory effect. The oil also exhibited potential fumigant toxicity toward Sitophilus oryzae and Tribolium castaneum. The results of the orthogonal partial least-square discriminant analysis revealed that α-pinene is the key bioactive component in Cupressus oil.