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F Osman

Publications and source records attributed to F Osman.

44 records · Page 3Linked to original sources
PubMed1976

Cottonseed colour fixed pigments. Part I. Selectivity of hexane isomers.

The selectivity of hexane isomers towards cottonseed pigments and colour fixed pigments was illustrated by using spectrophotometric analysis of crude, refined and bleached oils, and by refinability and bleachability criteria. Crude cottonseed oil contains besides the alkali-refinable gossypol and gossypurpurin, several colour fixed pigments. Anhydrogossypol, gossyfulvin, anthocyanins and carotenoids seem to be responsible for the colour-fixation of the oil. Only carotenoids are eliminated by bleaching. Selectivities of hexane isomers towards colour fixed pigments are in the following order: isohexane less than n-hexane less than cyclohexane less than benzene less than methylcyclopentane.

Alkanes↗
PubMed1976

Cottonseed colour fixed pigments. Part II. Role of hexane isomers on oil quality.

Colour fixed pigments can be detected in refined and bleached oils rather than in crude oils, since in the latter their absorption is masked up by the gossypol pigments. Isohexane is the most desirable hexane isomer. Though it produces darker crude oils, yet refinability and bleachability increases as the percentage of isohexane in normal hexan increases. It has also the advantage of extracting oils with lowest refining loss and with the highest gossypol content. Recovery of gossypol, which is alkali refinable, with the oil results in a superior quality of meal. Benzene, on the other hand, is the least desirable constituent in commercial hexane. Its presence with n-hexane results in darker coloured crude, refined and bleached oil colours, indicating the selectivity of benzene to colour fixed pigments. Highest refining loss were found in oils extracted with benzene or benzene-hexane solvent mixtures. Cyclohexane presence with n-hexane (35% to 60%) and methycyclopentane (6.0% to 12.0%) do not increase the degree of extraction of colour fixed pigments, however increase the refining loss of the extracted oils.

Alkanes↗
PubMed1976

Lipids of two Cassia species and Datura stramonium seeds.

The fatty acid constitution of three seed-oils, namely, Cassia alexandrina, Cassia italica and Datura stramonium, were carried out using gas chromatographic analysis. The glyceride structure of these oils was computed using the technique of pancreatic lipase hydrolysis. The phospholipids fraction of these oils were identified using thin layer chromatography, also the fatty acid constitution of the phosphilipids were determined quantitatively by gas liquid chromatography.

Fatty Acids↗
PubMedDate not supplied

Isolation and characterisation of nuv11, a mutation affecting meiotic and mitotic recombination in Aspergillus nidulans.

A mutant of Aspergillus nidulans, designated nuv11, has been isolated as hypersensitive to the monofunctional alkylating agent MNNG and the quasi-UV-mimetic mutagen 4-NQO. The mutation was recessive, resulting from mutation of a single gene which mapped to chromosome IV, and was non-allelic to the previously characterised repair-deficient mutations uvsB and uvsH which are also located on this linkage group. The nuv11 mutation results in slow growth, deficient intragenic and intergenic meiotic recombination, increased spontaneous chromosome instability, and increased intragenic and intergenic mitotic recombination in homozygous diploids. By screening a wild-type gene bank of A nidulans, a clone (pNUV11A40) has been isolated which complements the nuv11 mutation, restoring wild-type responses to both MNNG and 4-NQO.

4-Nitroquinoline-1-oxide↗