The present review discusses the role of tri-peptide Proline-Glycine-Proline (PGP) as a potential player, biomarker and therapeutic target in this process.

A green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of b-naphthol, aldehyde, and 6-amino-1, 3-dimethyluracil using L-Proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100oC is described. In this study, several types of aromatic aldehyde, containing electron withdrawing groups as well as electron-donating groups, were rapidly converted to the corresponding naphthopyranopyrimidine derivatives in good to excellent yields. The present approach offers several advantages such as short reaction times, simple work-up, excellent yields, non-toxicity of the catalyst, and solvent-free conditions. To the best of our knowledge, this is the first report on the synthesis of naphthopyranopyrimidine derivatives using L-Proline as a catalyst under solvent-free conditions. The catalysts can be recovered for the subsequent reactions and reused without any loss of efficiency.

Introduction: Honey is essentially a concentrated aqueous solution of invert sugar, but it also contains a very complex mixture of other carbohydrates, several enzymes, amino and organic acids, minerals, aroma substances, pigments, waxes, pollen grains, etc. The amino acids in honeys are attributable both to animal and vegetable sources, the major of these being pollen. Amino acids account for 1% (w/w), and Proline is the major contributor with 50-85% of the total amino acids.Materials and Methods: In this study, the destructive effect of processing at 55oC for 1 hour on honey Proline has been studied. By the application of spectrophotometer at 510nm the Proline contents before and after processing have been determined and compared.Results: The results of this study indicated that a reduction in Proline content was observed for all the samples and for the samples with high Proline content this wes significant.Conclusion: Proline's reduction in all the samples were observed due to the processing at 55oC for 1 hour. Consequently, processing at the higher temperatures caused higher reduction of Proline.

The direct three component modified Mannich reaction via condensation of aldehydes, 2-naphthol or 2, 7-naphthalendiol and piperidine to generate Betti bases has been carried out over L-Proline (20 mol%) with high efficiency under solvent-free conditions at 70oC. Also, the reaction of aromatic aldehyde and 4-hydroxycoumarin in the presence of L-Proline (20 mol%) in the ethanol under reflux conditions, lead to biscoumarin derivatives.

IR, Raman and surface-enhanced Raman scattering (SERS) spectra of L-Proline were recorded and analyzed. The molecular plane assumes a tilted orientation with respect to the metal surface. The vibrational wavenumbers and corresponding vibrational assignments are examined theoretically using the Gaussian 03 set of quantum chemistry codes.

Background and Objectives: Proline dehydrogenase (ProDH; 1.5.99.8) plays an important role in specific determination of plasma Proline level in biosensor and diagnostic kits. The goal of this research was to isolate and characterize ProDH enzyme from Iranian soil microorganisms.Materials and Methods: Screening of L-Proline degradative enzymes from soil samples was carried out employing enrichment culture techniques. The isolate was characterized by biochemical reactions and specific PCR amplification. The target ProDH was purified and the effects of pH and temperature on the activity and stability were also tested.Results: Among the 250 isolates recovered from 40 soil samples, only one strain characterized as Pseudomonas entomophila displayed the highest enzyme activity toward L-Proline (350 U/l) than others. The enzyme of interest was identified as a ProDH and had Km value of 32 mM for L-Proline. ProDH exhibited its best activity at temperature range of 25 to 35oC and its highest activity was achieved at 30oC. It was almost stable at temperatures between 25-30oC for 2 hours. The optimum pH activity of ProDH reaction was 8.5 and its activity was stable in pH range of 8.0-9.0 upto 24 hours. The enzyme was purified with a yield of 8.5% and a purification factor of 37.7. The molecular mass of the purified ProDH was about 40 kDa, and determined to be a monomeric protein.Conclusion: This is the first report concerning the ProDH production by a P. entomophila bacterium isolated from soil sample.

To study this, a research was conducted in greenhouse in a factorial experiment based on randomized complete blocks design with three replications. The first factor included stress levels and the second factor included genotypes. To apply Drought stress metanol was used. Seeds were planted in plastic pots in greenhouse conditions and plants irrigation was done by Hoagland nutrient solution. The Proline and chlorophyll of shoots were measured by the end of growth stage. Results suggested that genotype No. 4 with a mean of 19.25 had the highest rate of chlorophyll and genotype No. 1 with mean of 13.25 had the lowest chlorophyll rate. Also, genotype No. 3 with a mean of 5.86 had the highest Proline rate. Results indicated that Drought stress application could decrease chlorophyll rate while it increases Proline rate. Decrease in plant chlorophyll decreases the photosynthetic activity. Increase in Proline along with increase in Drought level specifies the osmotic balance maintenance in low water potential. Results generally showed that increase in Proline production as an osmotic regulatory mechanism in high Drought levels which decreases the seedling growth.