The R-amylolysis of potato, corn, waxy corn, and amaranthus starches with porcine pancreatic R-amylase upon illumination with visible polarized and nonpolarized light was studied. Samples were illuminated for 1 h either directly after blending the enzyme with starch or the enzyme solutions were illuminated for 1 h prior to the admixture of starch. Independently of the mode of illumination, no significant change in the hydrolysis kinetics was noted for corn, waxy corn, and amaranthus starches. The illumination of potato starch in the presence of R-amylase with polarized and nonpolarized light significantly accelerated the hydrolysis. In the first 5-h step the hydrolysis rate increased from 12.0 to 60.0 g kg -1 h -1 . Preillumination of enzyme in solution resulted in an increase in the rate of hydrolysis to 151.6 and 131.4 g kg -1 h -1 after illumination with polarized and nonpolarized light, respectively. Circular dichroism spectra of R-amylase solutions stored in the dark and illuminated with visible polarized and nonpolarized light provided evaluation of the protein conformation, whereas exposure of enzyme solutions to the nonpolarized did not change the secondary structure of the protein. The illumination of the R-amylase solutions with polarized light significantly changed the amounts of R-helix and β-form vs unilluminated samples: 42.3% and 25.5% vs 36.6% and 30.2%, respectively.

Aqueous suspensions (30%) of waxy corn and potato starches were illuminated for 5-50 h with linearly polarised visible light (λ > 500 nm). Molecular weights (M w ) and radii of gyration (R g ) of the amylopectin and amylose fractions of illuminated waxy corn starch, and the amylopectin, intermediate, and amylose fractions of illuminated potato starch were measured by high-performance size exclusion chromatography coupled with multiangle laser light scattering and refractive index detection. The weightaverage molecular weight (M w ) and radius of gyration (R g ) of the amylopectin fraction of native waxy corn starch were 14.45 × 10 7 and 161.1 nm respectively. After 15 h of illumination a decrease in M w (5.80 × 10 7 ) and R g (117.6 nm) was observed. Illumination for 25 h, led to an increase in M w (7.60 × 10 7 ) and R g (134.0 nm). Further illumination, up to 50 h resulted in a slight decrease in M w (6.74 × 10 7 ). The molecular weight and radius of gyration of the amylopectin fraction of native potato starch were 21.30 × 10 7 and 207 nm respectively. Illumination for 15 h led to a decrease in M w (14.87 × 10 7 ) and R g (141.5 nm), followed by an increase in both values after 25 h (18.97 × 10 7 , 146.6 nm) and 50 h (19.69 × 10 7 , 207.1 nm) of illumination. Illumination influenced the swelling power, solubility, susceptibility to α-amylolysis and X-ray diffractogram of the starches. A varying increase in the solubility passed through a minimum after 25 h of illumination. The X-ray diffraction pattern and susceptibility to enzymatic hydrolysis of waxy corn starch did not change, but in potato starch a gradual, illumination time-dependent increase in the amylolysis rate took place. This effect could result from the reduction in crystallinity of the starch as indicated by the X-ray diffraction pattern.

Fused pyridine derivativesFused pyridine derivatives R 0450 A Facile Synthesis of 4-Aryl-1H-pyrazolo[3,4-b]quinolines -[based on thermal or microwave-induced three-component coupling of aromatic amines, dihydropyrazoles and aromatic aldehydes]. -(CHACZATRIAN, K.; CHACZATRIAN, G.; DANEL, A.; TOMASIK*, P.; Pol.

In the reaction of anilines with 4-(benzylidene)-1,3-disubstituted pyrazol-5-ones, 1H-pyrazolo [3,4-b]quinolines were formed instead of anticipated 5-phenylimino derivatives. The same compounds were also available from the reaction of pyrazolin-5-ones with Schiff bases. In spite of moderate yields both methods present a facile route to 4-aryl-1H-pyrazolo [3,4-b]quinolines. These methods have advantages over the Friedländer cyclization commonly utilized for preparation of 4-aryl-1H-pyrazolo [3,4-b]quinolines. Thus, preparation of 2-aminobenzophenones, reagents indispensable in Friedlaender synthesis, can be avoided.