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The ionic-complementary self-assembling peptides discovered by Zhang Shuguang have solution-to-gel (sol-gel) transition capacity and one such peptide RADA16 has been commercialized into hemostatic agents. However, their sol-gel transition ability was not obvious because the peptide aqueous solution with a concentration greater than 1% w/v appeared to be thick and viscous. The current report describes PP-type self-assembling peptides. In addition to the ionic-complementary sequence, they have prolines at both ends of the sequence. This feature has led to better solubility, lower viscosity of the peptide solution, and simplified synthesis and purification processes while maintaining the great gelling performance of the ionic-complementary peptides. The PP-type peptides self-assembled into a well-organized nanofiber scaffold as shown by TEM. Among the PP-type peptides, the PRVDP9 sequence peptide was tested as a hemostatic agent and a mucosal elevating agent. The results were comparable to the classic RADA16. The PP-type self-assembling peptides have superior sol-gel transition ability. Therefore, it is predicted that they will be more suitable to be transported through catheters or endoscopes and have higher commercialization potential as compared with the classic self-assembling peptide sequences.

Desymmetrization of prochiral 3-substituted glutaronitriles offers a new approach to access (S)-Pregabalin and (R)-Baclofen. A number of nitrilases from diverse sources were screened with 3-isobutylglutaronitriles (1a) or 3-(4′-chlorophenyl)glutaronitriles (1b) as the substrate. Some nitrilases were found to catalyze the desymmetric hydrolysis of 1a and 1b to form optically active 3-(cyanomethyl)-5-methylhexanoic acid (2a) and 3-(4′-chlorophenyl)-4-cyanobutanoic acid (2b) with high enantiomeric excesse (ee), respectively. This cannot be achieved using traditional chemical hydrolysis. Among them, AtNIT3 generated (R)-2b, whereas BjNIT6402 and HsNIT produced the opposite (S)-enantiomer with high conversions and ee values. Not only the nitrilases showed different activities and stereoselectivities toward these 3-substituted glutaronitriles, the 3-substituent of the substrates also exerted great effect on the enzyme activity and stereoselectivity. (S)-2a and (S)-2b were prepared with high yields and ee values using BjNIT6402 and HsNIT as the biocatalysts, respectively. A straightforward Curtius rearrangement of (S)-2a and (S)-2b, followed by the acidic hydrolysis, afforded (S)-Pregabalin and (R)-Baclofen. This offers a new platform methodology for the synthesis of optically active β-substituted γ-amino acids of pharmaceutical importance.