The aim of the Thesis is the synthesis of mechanism-based inhibitors-inactivators of PLPdependent enzyme O-acetylserine sulfhydrylase (OASS) based on existing chemotypes, the investigation of new chemotypes, and the development of synthetic methods to facilitate the construction of potential PLP dependent enzyme inhibitors. The following tasks were set: 1. Design and synthesis of small library of potential OASS inhibitors. 2. Development of efficient protocol for the synthesis of quaternary alkynyl glycinols. 3. Development of synthetic methods to introduce terazole as a carboxylic acid bioisoster. The Thesis is a collection of scientific publications focused on the synthesis of triF-–Ala analogues and the development of methods for the synthesis of PLP-dependent enzyme inhibitors.