M. Zamil El-Faer

Levels of arsenic in fish from the Arabian Gulf

Abstract Levels of total arsenic were determined in muscle tissues of 13 species of finfish and 3 species of crustaceans from the Arabian Gulf. The range was 0.16–32.3 μg g −1 wet wt for finfish. Averages found for prawn, crab and lobster were 15.8, 6.28, and 12.7 μg g −1 wet wt, respecitively. The levels ranked among the highest reported in the literature.

Fatty acid composition of the meat and fat of the one-humped camel (camelus dromedarius)

The fatty acid composition of lean raw meat taken from the hind leg of seven young (1-3 years of age) male one-humped camels (Camelus dromedarius) has been determined by capillary gas-liquid chromatography; fat samples taken from the hump of these seven camels were also analysed. The saturated fatty acids in the meat account for 51·5% of the total fatty acids, while the monosaturated and polyunsaturated chains constitute 29·9 and 18·6%, respectively. The major fatty acids in camel meat are palmitic (26·0%), oleic (18·9%) and linoleic (12·1%), with smaller amounts of other fatty acids, both normal and branched, that range in chain lengths from C(14) to C(22). The fatty acids of dromedary fat are dominated by saturated even-numbered chains with smaller amounts (5·4%) of odd-numbered normal and branched chains. The main fatty acid of the hump fat is palmitic (34·4%) followed by oleic (28·2%), myristic (10·3%) and stearic (10·0%).

Mineral and proximate composition of the meat of the one-humped camel (Camelus dromedarius)

Abstract The information available on the nutritional value of the meat of the one-humped camel ( Camelus dromedarius ) is very limited. The mineral elements and proximate composition of muscle tissues taken from the shoulders, thighs, ribs, necks and humps of seven young (1–3 years) male camels have been determined. The amounts of mineral elements, protein and ash in the various muscle tissues of the camel are generally similar to the amounts reported for these constituents in the corresponding tissues of beef. However, the meat of the camel contains significantly less lipids (1·2–1·8% versus 4·0–8·0%) and higher water content (5–8% more) than beef. The hump consists mainly of lipids (86·9%).

Mineral and proximate composition of some commercially important fish of the Arabian Gulf

Abstract The information available on the chemical composition of the fish being harvested from the Arabian Gulf is very limited. The levels of nine nutrient minerals and the proximate components of the raw (fresh) edible portions of some commercially important finfish and shellfish were determined. All the fish investigated were fairly high in protein (18–22%) while the lipid content was less than 3%. Small amounts of carbohydrates were detected only in shellfish. The moisture and ash content varied within a narrow range. The levels of minerals varied from one fish species to the other. In finfish the most abundant mineral was potassium followed by phosphorus with lower levels of sodium, magnesium and calcium. Similar trends were observed in shellfish except for sodium which was present in amounts comparable to that of potassium.

A short hydrogen bonded columnar structure: synthesis, spectroscopic studies and X-ray structure of a palladium(II) complex of alfa-furil dioxime

Abstract Synthesis, spectroscopic studies and single crystal X-ray structure of [Pd(Hafdo)2], where H2afdo is α-furilglyoxime, were carried out because of its potential columnar stack structure and the existence of a short intramolecular hydrogen bond. The compound crystallizes in the orthorhombic space group Pnab with a=6.930(3), b=14.286(2) and c=19.837(4) A. The intensity data were collected on a CAD-4 diffractometer and the structure was refined to a final R value of 6.1%. The central metal atom in this inner complex has planar geometry and the oxime oxygen atoms are involved in a short intramolecular hydrogen bond with O[sbnd]O distance of 2.583(4) A. The complex molecules are stacked above one another along the crystallographic a axis with adjacent molecules rotated 90° with respect to each other. The Pd-Pd distance is 3.465(4) A. The two oxygen atoms of the planar furane groups are separated by 2.686(4) A and the furane rings are oriented at an angle of 46.7° with respect to each other. The columna...

MACROCYCLIZATION OF TRANSITION METAL COMPLEXES OF ALPHA-FURILGLYOXIME AND BENZILGLYOXIME

Abstract The α-furil- and benzilglyoximates of nickel (II), palladium(II), platinum(II), cobalt(III), rhodium(III) and rhenium(III) have been prepared in a crystalline state and the corresponding macrocycles obtained by reaction with BF3·OE2 utilizing the metal ion as a template. The planar glyoximates yielded macrocycles whereas the macrocyclization of octahedral complexes could not be accomplished. The reactions and the predicted structures have been compared with known structures.

Investigation of the conformational properties of cyclododecanone by iterative force-field calculations

Abstract Iterative force-field calculations show that the lowest energy conformation of Cyclododecanone ( 1 ) is the [3333]-2-one. Two conformational processes are needed to achieve pseudorotation of the [3333]-2-one conformation: one of these processes leads to time averaged C 2 -symmetry in 1 , while the other results in time averaged C s -symmetry in 1 .

Macrocyclic nickel(II) complexes: Spectroscopic studies and crystal structure of bis(difluoroboron-alpha-furilglyoximato)nickel(II)

Abstract Bis (difluoroboron - α - furilglyoximato) nickel (II), C 20 H 12 O 8 N 4 B 2 F 4 Ni, was prepared by cyclization of its hydrogen-bonded precursor with BF 3 ·OEt 2 . The compound crystallizes in the space group P 2 1 / c with a = 11.162(2), b = 5.569(2), c = 19.527(3) A, β = 100.08(1)°, U = 1195.1(3) A 3 , and Z = 2. The structure was refined to an R value of 0.033 using 2371 unique reflections collected with a CAD4-SDP diffractometer system. Unlike the corresponding planar macrocyclic as well as hydrogen-bonded dimethylglyoximates, the title compound neither dimerizes not exhibits columnar stacked structure. The 14-member macrocycle is planar except the B atoms, and no metal-metal interactions are observed in this compound. The complexation and cyclization reactions were investigated using spectral data. The structure is compared with other macrocyclic complexes.

Short Intramolecular Hydrogen Bonds: Proton-NMR and IR Spectra as a Function of O - - - O Distance

Abstract Infrared absorption frequencies and 1H NMR chemical shifts have been measured as a function of O—O distances in compounds with short intramolecular hydrogen bonds. Two types of molecules were investigated, those with intramolecular O-H-O bonds within chelate or constrained systems having no degree of rotational freedom along the O-H-O axis, and molecules possessing symmetry-restricted or unrestricted hydrogen bonds with complete rotational freedom along the O - - H - - O axis. While electronic factors are most important for the nature of the short hydrogen bond in the latter compounds (such as dimeric hydronium ions of pyridine-N-oxides), steric constraints play a dominant role for the former (such as metal glyoximates). 1H MMR chemical shifts δ(O-H-O) (ppm) and IR absorption frequencies v(O-H-O) (cm−1) as a function of the O — O distance are discussed.

CONFORMATIONAL ANALYSIS OF CIS,TRANS,TRANS-1,5,9-CYCLODODECATRIENE

Abstract cis, trans, trans -1,5,9-Cyclododecatriene (1) exists as a single conformation. Two conformational processes are needed for the pseudorotation of 1 : One process leads to time-averaged CS-symmetry (ca. 6 kcal/mol) and the other to time-averaged C2-symmetry (12.4 kcal/mol).