Muscanone: a 3-O-(1", 8", 14"-trimethylhexadecanyl)naringenin from Commiphora wightii

A new antifungal flavanone, muscanone (1), was isolated along with known naringenin (2) from Commiphora wightii (Arn.) Bhandari (Burseraceae) by directing the fractionation of an EtOH extract of the air-dried trunk of C. wightii with microbial sensitivity assay. The structures of 1 and 2 were determined from EIMS, HREIMS, DEPT, 1H-1H COSY, HSQC and HMBC spectral data. Muscanone (1) was identified as 3-O-(1", 8",14"-trimethylhexadecanyl)naringenin and was found to be active against Candida albicans. The isolation, structure elucidation, NMR spectral assignments, and bioactivities of 1 and 2 are reported.     

Design, synthesis, single-crystal and preliminary antitumor activity of novel arenesulfonylimidazolidin-2-ones

Novel series of 1-(arenesulfonyl)imidazolidin-2-one (3a-i) and 1,3-bis(arenesulfonyl)imidazolidin-2-one (5a-i) have been synthesized and tested for their antitumor activity against 60 tumor cell lines taken from nine different organs. A significant inhibition for cancer cells was observed with series 5a-i compounds compared with the series 3a-i which showed a weak inhibition. Compounds 5a-i showed good inhibitory effect at the lung cancer HOP-92 and renal cancer CAKI-1 and UO-31 cell lines. Compound 5e showed remarkable broad-spectrum antitumor activity.     

Effects of Echis pyramidum Snake Venom on Hepatic and Renal Antioxidant Enzymes and Lipid Peroxidation in Rats

The effects of Echis pyramidum venom (EPV) (0.25, 0.50, and 1.00 mg/kg) on activities of superoxide dismutase (SOD) and catalase (CAT) and levels of thiobarbituric acid reactive substances (TBARS) and total thiols (T‐SH) in liver and kidneys of rats were investigated. EPV significantly and dose dependently decreased the activities of SOD and CAT in livers. Although the kidney SOD and CAT activities were not affected by low and medium doses of EPV, the high dose significantly reduced the activities of these enzymes. Liver and kidney TBARS levels were not affected by the low and medium doses of EPV, whereas the high dose significantly increased the TBARS after 6 h postdosing. There was a significant depletion of T‐SH in liver and kidneys of rats exposed to a high dose of EPV. The acute phase oxidative stress due to an EPV injection points toward the importance of an early antioxidant therapy for the management of snake bites.     

Microcystin-producing blooms of Anabaenopsis arnoldi in a potable mountain lake in Saudi Arabia

This study reports for the first time the presence of Anabaenopsis arnoldi blooms in Saudi freshwaters. This species has been investigated with high cell densities (3.8 × 10³–264 × 10³ cells mL⁻¹) during June–November 2007 in Tendaha Lake, one of the major freshwater sources in Saudi Arabia. High temperature and conductivity, and a high concentration of phosphate, and low nitrate concentrations may have contributed to the formation of these blooms. The blooms were found to produce microcystins (MCYSTs) at concentrations up to 364 μg g⁻¹ dry weight as detected by an enzyme-linked immunosorbent assay. MCYSTs were also detected in the raw and treated water of the lake at concentrations (1.6–8.3 and 0.33–1.6 μg L⁻¹, respectively) exceeding the World Health Organization guideline level of 1 μg L⁻¹ for these toxins. HPLC analysis revealed that the extracts of A. arnoldi blooms contained MCYST-RR, -YR and two unidentified MCYSTs, but a pure culture of A. arnoldi isolated from Tendaha Lake during the present study produced MCYST-RR and –YR only. This is the first study to report MCYST production by A. arnoldi . Therefore, this cyanobacterium should be taken into consideration during monitoring of toxic cyanobacterial blooms in drinking and recreational water sources in the world, particularly arid and semi-arid countries including Saudi Arabia.     

Role of cyclic AMP in the action of dopaminergic D2 receptors of some endocrine glands in rats

Short-term and long-term effects of bromocriptine mesylate (10 mg/kg i.p.) on cyclic AMP contents of the liver and some endocrine glands have been investigated in the presence and absence of sulpiride (10 mg/kg i.p.). Results revealed that bromocriptine caused significant elevations in the cyclic AMP contents of the liver and reduction in its adrenocortical content. Bromocriptine effect on the adrenal cortex was antagonized by sulpiride, whereas its effect on the liver was not changed. Bromocriptine did not change the, cyclic AMP content in the thyroid gland or the ovary.     

Observations on the diagenesis of the Lower Triassic Sudair Formation,Abu Dhabi,United Arab Emirates

Summary The Lower Triassic Sudair Formation in the United Arab Emirates (U.A.E.) ranges in thickness from 178–297 m and comprises three units consisting of interbedded limestone, argillaceous limestone, dolomite and anhydrite. The Lower Unit contains variable energy shallow marine, slightly argillaceous mudstones and subordinate ooliticpeloidal packstones and grainstones with minor dolomite and anhdrite. The Middle Unit consists of argillaceous and ferroan dolomite deposited in a lagoonal to supratidal setting. The Upper Unit comprises argillaceous mudstones and dolomites at the base grading upward into argillaceous anhydrite deposited in a restricted shallow marine to sabkha setting. These units represent the transition from a carbonate/evaporite shelf with significant terrestrial input to an evaporitic platform defined by an overall shallowing-upward sequence. Diagenesis in the Sudair includes extensive leaching of grain-supported carbonates, partial to complete dolomitization, evaportie formation, clay nucleation, fracturing/pressure solution, late cementation by coarse calcite spar and saddle dolomite, and hematite formation. These processes have had the cumulative effect of reducing the secondary porosity. Dolomitization occurred in two stages: an earlier progression of rhombic-sucrosic-aphanocrystalline dolomite, and a later coarse crystalline and saddle dolomite fracture fill.     

CHLOROPHYLL LEVELS AND LEAF ULTRASTRUCTURE AS ECOTYPIC CHARACTERS IN XANTHIUM STRUMARIUM L.

Comparison of six different populations of Xanthium strumarium grown under controlled laboratory conditions revealed a general pattern of greater chlorophyll levels with increase in latitude of origin. Indications of ultrastructural differences were found, with plants containing greater chlorophyll levels having more chloroplasts with greater membrane development compared to plants of this species from more southern or lower latitude habitats.