CCK2–Gastrin Antagonist: Development of PNB-001 (4-Chloro- 5-Hydroxy-1-Phenylethyl-5-Phenyl-1, 5-Dihydro-Pyrrol-2-one) as Anti-Inflammatory Analgesic

Study aim: To prepare and evaluate CCK gastrin antagonists from readily available materials such as furfural and to focus on inflammatory pain management. Methods: Receptor binding assays, isolated tissue preparations and selected animal models were applied to evaluate the lead molecule PNB-001. Results: Arylated 5-hydroxy–pyrrol-2-ones were prepared in 3 synthetic steps from furfural and subsequently optimised as CCK2 selective ligands using radiolabelled binding assays. Originally a CCK1 selective lead structure was identified and from that lead, a potent and selective CCK2 ligand (PNB-001, IC50= 22 nM) was fully SAR optimised. The antagonism was confirmed for PNB-001 by using isolated tissue preparations with CCK5. Subsequent in vivo evaluation revealed analgesic activity for the gastrin CCK2 antagonist PNB-001, in the hotplate and tail immersion test at 0.5mg /kg by IP administration in mice. PNB-001 was superior in the formalin test to the morphine standard by oral administration and in the x-maze test the anxiolytic activity was greater in magnitude than diazepam. Conclusion: The front runner PNB-001 completed preclinical development and will enter clinical phase 1

Lectins: production and practical applications

Lectins are proteins found in a diversity of organisms. They possess the ability to agglutinate erythrocytes with known carbohydrate specificity since they have at least one non-catalytic domain that binds reversibly to specific monosaccharides or oligosaccharides. This articles aims to review the production and practical applications of lectins. Lectins are isolated from their natural sources by chromatographic procedures or produced by recombinant DNA technology. The yields of animal lectins are usually low compared with the yields of plant lectins such as legume lectins. Lectins manifest a diversity of activities including antitumor, immunomodulatory, antifungal, HIV-1 reverse transcriptase inhibitory, and anti-insect activities, which may find practical applications. A small number of lectins demonstrate antibacterial and anti-nematode activities