In view of synthetic utility and biological importance of tetrazole derivatives, 1′-phenylethyl undec-10-enoate, 1′-phenylethyl (Z)-octadec-9-enoate and 1′-phenylethyl (Z)-12-hydroxyoctadec-9-enoate have been converted into their α-bromo 5-methyl tetrazole derivatives, using bromine, acetonitrile and sodium azide as reagents. The structure elucidation of the prepared compounds is based on elemental analysis and spectral data.
A new quantification method for triglyceride (TG) molecular species contained in fish oil was developed using high performance liquid chromatography (HPLC)-ultraviolet detector (UV) system. In this experiment, triacontyl silane column and a mixture of alcohol and acetonitrile were used for column and mobile phase, respectively. Fifteen kinds of TG molecular species exist in fish oil were collected and the calibration curves monitored at 210nm were acquired for each TG molecular species. Also, evaporative light scattering detector (ELSD), widely used for the detection of fish oil TG molecular species, was tandem jointed after UV to compare the calibration curves for each TG molecular species. As the results, the calibration curves by UV with isocratic elution system were linear lines, on the contrary, those by ELSD were not linear. The slope of each calibration curve by UV was not the same and there was a tendency that TG molecular species having big partition number indicates a small slope calibration curve. The HPLC-UV with gradient system was also examined, but a few of standard TGs did not provide linear calibration curve. Consequently, we concluded that isocratic HPLC-UV system would be an available method for the quantification of TG molecular species in fish oil.
The hair of consumers using hair colors frequently suffers from serious damage to silky feeling on their hair, of which surface turns hydrophilic with hair dye and hair bleach. The damaged hair can be dramatically recovered with applying diglucosyl gallic acid (DGA) and alkyl quaternary ammonium salt on the colored hair. These compounds form a hydrophobic layer (artificial F-layer) on the damaged surface of cuticle, and anchor so firmly that the artificial F-layer is hardly washed off with shampoo. DGA is proposed to be a new cosmetic ingredient, which is a very useful agent for the recovery of damaged hair due to coloring.
Human lipoprotein (a) [Lp(a)] binds to the fibrinogen (GPIIb/IIIa) receptor at the CD41 or GPIIb protein on unstimulated platelets. However, this binding has never been examined on stimulated platelets. Different amounts (1-100 mg%) of purified human Lp(a) and fibrinogen (50 mg/100 ml) were incubated with washed human platelets in the presence or absence of an anti-CD41 monoclonal antibody (Mab) directed at the GPIIb protein of the fibrinogen receptor. Mab inhibited binding of Lp(a) and fibrinogen to the GPIIb protein and abolished Lp(a)-induced reduction of platelet aggregation. In a second experiment, washed platelets were incubated with Lp(a) and Mab or with fibrinogen and Mab and then agonist-stimulated, resulting in a reduction of binding of Lp(a) or fibrinogen. It was concluded that Lp(a) must bind to the GPIIb site to reduce platelet aggregation which apparently occurs via a competition of Lp(a) and fibrinogen for the same site on the IIb portion of the fibrinogen binding site on agonist-stimulated human platelets.
Synthesis of L-menthyl eicosapentaenoate was achieved through lipase-catalyzed esterification of eicosapentaenoic acid (EPA) with L-menthol in an organic solvent-free system. A suitable enzyme was a lipase from Candida rugosa (Lipase-AY, Amano Enzyme Inc., Aichi) when L-menthol was esterified at 30°C in a mixture of L-menthol/EPA (1.2/1, mol/mol), 20 wt% water and 1600 U/g-mixture of lipase. The reaction reached equilibrium after 3 d at ca. 75% esterification. L-Menthyl γ-linolenate and arachidonate could also be synthesized under the same conditions as those in synthesis of L-menthyl eicosapentaenoate, although the degrees of esterification after 4 d were 54 and 41%, respectively. Synthesis of L-menthyl eicosapentaenoate greatly depended on the water content, and reaction rate significantly decreased in the presence of < 20% of water.
The spectroscopic behaviors of arenediazonium ions in the absence and the presence of a novel calixarene 1,3-alternate conformer possessing two (ethoxycarbonyl) methoxy groups 4 were studied by UV-visible, 1H NMR, and IR spectra for the first time. 1,3-alternate conformer 4 exhibits the large hyposochromic shifts of 85 nm and the binding constants (Ka) values are greater than 104 M-1, indicating the fact that 4 strongly associates with the diazo group, the interaction being comparable with that with 18-crown-6. However, 4 can not inhibit the dediazoniation of the diazo group indicating the mechanism (A), the macrocyclic effect which sterically inhibits dediazoniation proceeding from the linear Ar-N+ ≡ N inserted in the crown ring to the bulky π-intermediate II, is responsible for the stabilization of the diazo group.