Oxyazapeptides: Synthesis, Structure Determination, and Conformational Analysis
作者:Suvendu Biswas、Nader E. Abo-Dya、Alexander Oliferenko、Amir Khiabani、Peter J. Steel、Khalid A. Alamry、Alan R. Katritzky
DOI:10.1021/jo401234g
日期:2013.9.6
we report the synthesis, X-ray structure determination, and conformationalanalysis of a novel class of heteroatom-modified peptidomimetics, which we shall call “oxyazapeptides”. Substituting the typical native N-Cα bond with an O-Nα bond creates a completely new, previously unknown family of peptidomimetics, which are hydrolytically stable and display very interesting conformational behavior. Force
<i>S</i>- to<i>N</i>-Acyl transfer in<i>S</i>-acylcysteine isopeptides via 9-, 10-, 12-, and 13-membered cyclic transition states
作者:Oleg Bol'shakov、Judit Kovacs、Mamta Chahar、Khanh Ha、Levan Khelashvili、Alan R. Katritzky
DOI:10.1002/psc.2438
日期:2012.11
S‐Acyl cysteine peptides containing α‐, β‐ or γ‐amino acid residues undergo long‐range S‐ to N‐acyl transfer to give analogs of native tripeptides and tetrapeptides containing additional carbon atoms in the chain. The ease of intramolecular S → N‐acyl transfer relative to intermolecular transacylation is favored increasingly for 9 < 12 < 13 ~ 10‐membered cyclic transition states; the observed order
Ligations from Tyrosine Isopeptides via 12- to 19-Membered Cyclic Transition States
作者:Vadim Popov、Siva S. Panda、Alan R. Katritzky
DOI:10.1021/jo4009468
日期:2013.8.2
Efficient syntheses of O-acyl Tyr-peptides allow chemical long-range ligation (O-acyl to N-acyl transfer) via each of 12- to 19-membered cyclictransitionstates. The results represent the first examples of successful isopeptideligations starting fromO-acyl Tyr-peptides.
(α-Aminoacyl)amino-Substituted Heterocycles and Related Compounds
作者:Alan R. Katritzky、Bahaa El-Dien M. El-Gendy、Ekaterina Todadze、Ashraf A. A. Abdel-Fattah
DOI:10.1021/jo8007379
日期:2008.7.1
N-Protected-(aminoacyl)benzotriazoles 1a−e,g,i,j,1a′−c′ convert heterocyclic amines of the following series: thiazoles (3a and 3a′), benzothiazoles (3b and 3b′), benzimidazoles (3c and 3c′), thiadiazoles (3d), pyrimidones (9a,b,a′), pyrazoles (11a,b), and pyridines (13a−g, 13d′) under microwave irradiation, into N-substituted amides in yields of 40−98% (average 76%). N-Protected peptidoylbenzotriazoles
Synthesis and molecular modeling of antimicrobial active fluoroquinolone–pyrazine conjugates with amino acid linkers
作者:Siva S. Panda、Oleksandr S. Detistov、Adel S. Girgis、Prabhu P. Mohapatra、Ahmed Samir、Alan R. Katritzky
DOI:10.1016/j.bmcl.2016.03.062
日期:2016.5
Novel fluoroquinolone–pyrazine conjugates 7a–h with aminoacid linkers were synthesized in good yields utilizing benzotriazole chemistry. Antimicrobial bioassay showed that the synthesized bis-conjugates have antimicrobial properties comparable to the parent drugs. Compound 7h showed superior antibacterial activity against Staphylococcus aureus and Streptococcus pyogenes (MIC = 74.6 μM and 149.3 μM