Superacid and thiol-ene reactions for access to psammaplin analogues with HDAC inhibition activities

Probing into the plasma stability and microsomal stability of thiol-based prodrug derivatives: Using IYS-15, an HDAC inhibitor as the model thiol

Thiols have interesting bio-chemical properties and can be found in a number of approved drugs. However, some thiols exhibited poor plasma stability and microsomal stability, leading to poor in vivo activity and poor oral bio-availability, in spite of their potent activity in vitro. Prodrug is a classic strategy to improve drug pharmacokinetics. In this study, we designed and synthesized 25 prodrug derivatives of a potent thiol-based HDAC inhibitor, IYS-15, to explore the structure-plasma stability relationships and structure-microsomal stability relationships in these series. We also tried to identify the main metabolic enzymes participated in the metabolism of some representative thiol-based prodrug derivatives. This work thus presents a comparison between different prodrugs based on the same model thiol, giving insights into the stability profile of the synthesized prodrug derivatives in human plasma and human liver microsomes, and more importantly, might also provide structural guidance to medicinal chemists in the design of thiol-based prodrugs and other novel prodrugs with thiol-based linkers.

Electrophilically Activated Nitroalkanes in Reactions With Carbon Based Nucleophiles

Unusual reactivity of nitroalkanes, involving formation of aci-forms (nitronic acids or nitronates) and their subsequent interaction with carbon-based nucleophiles, is surveyed in this review.

Marine-Derived Natural Lead Compound Disulfide-Linked Dimer Psammaplin A: Biological Activity and Structural Modification

Marine natural products are considered to be valuable resources that are furnished with diverse chemical structures and various bioactivities. To date, there are seven compounds derived from marine natural products which have been approved as therapeutic drugs by the U.S. Food and Drug Administration. Numerous bromotyrosine derivatives have been isolated as a type of marine natural products. Among them, psammaplin A, including the oxime groups and carbon-sulfur bonds, was the first identified symmetrical bromotyrosine-derived disulfide dimer. It has been found to have a broad bioactive spectrum, especially in terms of antimicrobial and antiproliferative activities. The highest potential indole-derived psammaplin A derivative, UVI5008, is used as an epigenetic modulator with multiple enzyme inhibitory activities. Inspired by these reasons, psammaplin A has gradually become a research focus for pharmacologists and chemists. To the best of our knowledge, there is no systematic review about the biological activity and structural modification of psammaplin A. In this review, the pharmacological effects, total synthesis, and synthesized derivatives of psammaplin A are summarized.

Inside HDACs with more selective HDAC inhibitors

Inhibitors of histone deacetylases (HDACs) are nowadays part of the therapeutic arsenal mainly against cancers, with four compounds approved by the Food and Drug Administration. During the last five years, several groups have made continuous efforts to improve this class of compounds, designing more selective compounds or compounds with multiple capacities. After a survey of the HDAC biology and structures, this review summarizes the results of the chemists working in this field, and highlights when possible the behavior of the molecules inside their targets.