An expedient synthesis of N(alpha)-protected-L-tetrahydrofuranylglycine and its application in the synthesis of novel substrate based inhibitors of HIV-1 protease

The application of bioisosteres in drug design for novel drug discovery: focusing on acid protease inhibitors

INTRODUCTION

A bioisostere is a powerful concept for medicinal chemistry. It allows the improvement of the stability; oral absorption; membrane permeability; and absorption, distribution, metabolism and excretion (ADME) of drug candidate, while retaining their biological properties. The term 'bioisostere' is derived from 'isostere', whose physical and chemical properties, such as steric size, hydrophobicity, and electronegativity, are similar to those of a functional or atomic group, and is considered to possess biological properties. Here, the authors highlight the recent applications of bioisosteres in drug design, mainly based on our drug discovery studies.

AREAS COVERED

This review discusses the application of bioisosteres for novel drug discovery with focus on the authors' drug discovery studies such as renin, HIV-protease, and β-secretase inhibitors. The authors highlight that some bioisosteres can form the scaffolding for drug candidates, namely substrate transition state, amide/ester, and carboxylic acid bioisosteres. Moreover, the authors propose the new terms 'electron-donor bioisostere' and 'conformational bioisostere' for drug discovery.

EXPERT OPINION

The authors discuss the importance of bioisostere's design concept based on specific interaction with the corresponding biomolecule. In addition, some strategies for drug discovery based on the bioisostere concept are introduced. Many bioisosteres, which are recognized by corresponding target biomolecules as exhibiting similar biological properties, have been reported to date; most of the recently developed bioisosteres were designed by cheminformatics approaches. Some molecular design softwares and databases are introduced.

α-Vinylic Amino Acids: Occurrence, Asymmetric Synthesis and Biochemical Mechanisms

This report presents an overview of the family of naturally occurring 'vinylic' amino acids, namely those that feature a C-C double bond directly attached to the α-carbon, along the side chain. Strategies that have been brought to bear on the stereocontrolled synthesis of these olefinic amino acids are surveyed. The mechanistic diversity by which such 'vinylic triggers' can be actuated in a PLP (pyridoxal phosphate) enzyme active site is then highlighted by discussions of vinylglycine (VG), its substituted congeners, particularly AVG [4E-(2'-aminoethoxy)vinylglycine], and a naturally occurring VG-progenitor, SMM (S-methylmethionine).