An expeditious method for the synthesis of homo and heterochiral dipeptides containing l-alanine and d/l 2-methyl allo-hydroxyl prolines was developed using direct aminolysis of bicyclic lactones derived from d/l alanine. The impact of C-2 methylation and its spatial orientation on the pyrrolidine ring puckering and prolyl amide bond configuration was ascertained by solution NMR studies. The present studies reveal that C-2 methylation causes the prolyl amide bond to exist exclusively in the trans geometry in both homo- and heterochiral dipeptides. However, the spatial orientation of the C-2 methyl group and its i + 2 position in appropriately capped model dipeptides may nucleate into a turn like structure.
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http://dx.doi.org/10.1039/c9ob00150f | DOI Listing |
Org Biomol Chem
November 2024
Department of Chemistry, Indian Institute of Science, Bangalore, Karnataka - 560012, India.
NMR spectral and theoretical analyses of homologous prolyl carbamates reveal subtle charge transfer tetrel bonding interactions (TBIs), selectively stabilizing their Pro rotamers. These TBIs involve C-terminal-amide to N-terminal carbamate carbonyl-carbonyl (n → π* type) followed by intra-carbamate (n → σ* type) charge transfer interactions exclusively in the Pro motif. The number of TBIs and hence the Pro stability increase with increasing number of C groups at the carbamate alcohol.
View Article and Find Full Text PDFBackground: Genetic association studies can reveal biology and treatment targets but have received limited attention for stroke recovery. STRONG (Stroke, Stress, Rehabilitation, and Genetics) was a prospective, longitudinal (1-year), genetic study in adults with stroke at 28 US stroke centers. The primary aim was to examine the association that candidate genetic variants have with (1) motor/functional outcomes and (2) stress-related outcomes.
View Article and Find Full Text PDFACS Omega
July 2024
Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
Nonribosomal peptide synthetases (NRPSs) are important enzymes that synthesize an array of nongenetically encoded peptides. The latter have diverse physicochemical properties and roles. NRPSs are modular enzymes in which, for example, the condensation (C-) domain catalyzes the formation of amide bonds.
View Article and Find Full Text PDFSci Rep
July 2024
Division of Renal Diseases and Hypertension, Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, NW, Washington, DC, 20052, USA.
The kidney and brain play critical roles in the regulation of blood pressure. Neuropeptide FF (NPFF), originally isolated from the bovine brain, has been suggested to contribute to the pathogenesis of hypertension. However, the roles of NPFF and its receptors, NPFF-R1 and NPFF-R2, in the regulation of blood pressure, via the kidney, are not known.
View Article and Find Full Text PDFInt J Biol Macromol
August 2024
Chemistry Department, Faculty of Science, Menoufia University, Shebin El-Koam 32511, Egypt.
Prolyl oligopeptidase (POP) is a compelling therapeutic target associated with aging and neurodegenerative disorders due to its pivotal role in neuropeptide processing. Despite initial promise demonstrated by early-stage POP inhibitors, their progress in clinical trials has been halted at Phase I or II. This impediment has prompted the pursuit of novel inhibitors.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!