7 research outputs found
Synthetic Studies in Phytochrome Chemistry
An account is given of the author’s several approaches to the synthesis of the parent chromophore of phytochrome (1), a protein-bound linear tetrapyrrole derivative that controls photomorphogenesis in higher plants. These studies culminated in enantioselective syntheses of both (2R)- and (2S)-phytochromobilin (4), as well as several 13C-labeled derivatives designed to probe the site of Z,E-isomerization during photoexcitation. When reacted in vitro, synthetic 2R-4 and recombinant-derived phytochrome apoprotein N-C produced a protein-bound chromophore with identical difference spectra to naturally occurring 1
Room-Temperature Palladium-Catalyzed Amination of Aryl Bromides and Chlorides and Extended Scope of Aromatic C−N Bond Formation with a Commercial Ligand
Tertiary Building Units: Synthesis, Structure, and Porosity of a Metal−Organic Dendrimer Framework (MODF-1) ⊥
Optimization of Pyrrolamide Topoisomerase II Inhibitors Toward Identification of an Antibacterial Clinical Candidate (AZD5099)
AZD5099
(compound <b>63</b>) is an antibacterial agent that
entered phase 1 clinical trials targeting infections caused by Gram-positive
and fastidious Gram-negative bacteria. It was derived from previously
reported pyrrolamide antibacterials and a fragment-based approach
targeting the ATP binding site of bacterial type II topoisomerases.
The program described herein varied a 3-piperidine substituent and
incorporated 4-thiazole substituents that form a seven-membered ring
intramolecular hydrogen bond with a 5-position carboxylic acid. Improved
antibacterial activity and lower in vivo clearances were achieved.
The lower clearances were attributed, in part, to reduced recognition
by the multidrug resistant transporter Mrp2. Compound <b>63</b> showed notable efficacy in a mouse neutropenic Staphylococcus
aureus infection model. Resistance frequency versus
the drug was low, and reports of clinical resistance due to alteration
of the target are few. Hence, <b>63</b> could offer a novel
treatment for serious issues of resistance to currently used antibacterials