We have described experiments involving the use of five crystalline isomers of retinene: the ordinary crystalline substance known previously from the work of Ball, Goodwin, and Morton (1948); neoretinenes a and b, first iso. lated in our laboratory; and isoretinenes a and b, isolated in the Organic Re. search Laboratory of Distillation Products Industries (Hubbard and Wald 1952; 1952-53). By al...

The analysis of beta-carotene and lycopene, the two predominant carotenoids in human serum and tissues, was extended to the level of geometrical (cis-trans) isomers by using an improved reversed-phase HPLC methodology. We separated five geometrical isomers of beta-carotene and seven of lycopene in human serum and tissues. 13-cis-beta-Carotene was identified as the predominant cisisomer in human...

4-Methylaminorex, a potential psychostimulant drug of abuse, exists as four stereoisomers: cis-4R,5S, cis-4S,5R, trans-4S,5S, and trans-4R,5R, which were shown previously to possess stereospecific effects. This study characterized their pharmacokinetic and tissue distribution profiles, and metabolic turnover to norephedrine and norpseudoephedrine, in male Wistar rats. The rats received each iso...

Conjugated linoleic acid (CLA) refers to a group of positional and geometric isomers of linoleic acid. Studies using animal models have shown that CLA reduces adiposity, improves plasma lipoprotein metabolism and insulin sensitivity and reduces arteriosclerosis. Whilst CLA may have therapeutic potential with regard to coronary artery disease risk factors in human subjects, there has been little...

The retinal epithelium plays an important role in the storage and metabolism of retinoids in the eye. Studies were conducted to examine the enzymatic hydrolysis of retinyl esters by human retinal epithelial cells. Homogenates prepared from these cells were found to hydrolyze both the 11-cis- and all-trans-isomers of retinyl palmitate. Retinyl ester hydrolysis was time-, protein-, and pH-depende...

The title mol-ecule, C26H16O2, crystallizes as a mol-ecular crystal with no strong inter-molecular inter-actions (the shortest C-H⋯O contact is longer than 3.4 Å). Two flat ace-naphthyl-ene groups of neigboring 1,2-di-benzoyl-ace-naphthyl-ene mol-ecules are related by a crystallographic center of symmetry and are stacked with the distance between their mean planes of 3.37 (1) Å, apparently maki...

Formation of sterically hindered C−C double bonds via catalytic olefin metathesis is considered a very challenging task for Ru catalysts. This limitation led to the development specialised catalysts bearing reduced N-heterocyclic carbene (NHC) ligands that are active in such transformations, yet significantly less stable as compared general purpose To decrease small-size NHC susceptibility deco...

Cell killing and mutation induction by cis- and trans-Pt(NH3)2Cl2 in Escherichia coli were examined by studying forward mutagenesis in the lacI gene in cells with different repair capacities. Survival experiments showed that repair-proficient cells were slightly more sensitive for the cis isomer than for the trans isomer, whereas repair-deficient RecA and UvrB cells were extremely sensitive onl...

In solution, unsubstituted guanine (GH2) is in a tautomeric equilibrium between 1H,7H-keto and 1H,9H-keto forms. Upon coordination with (dien)Pt(II), N9-bound mononuclear complex is preferentially formed. With excess (dien)Pt(II), the dinuclear complex [{Pt(dien)}2(GH-N7,N9)]3+ is formed at basic pH. The X-ray crystal structure analysis of mononuclear complexes [Pt(dien)(GH2-N9)](ClO4)2 x 2.25 ...

This study was carried out to investigate the effect of different cooking techniques applied meats on total CLAs, cis-9,trans-11-CLA (c9,t11-CLA) and trans-10,cis-12-CLA (t10,c12-CLA). . In study, four methods such as boiling, frying, baking grilling were meat samples taken from bovine carcasses. raw cooked samples, CLA, cis-9, trans-11 trans-10, cis-12 isomer amounts examined in Gas Chromatogr...