Professor, Dr. Sc.

Valentin A. Stonik is one of the pioneers in marine natural products chemistry.

His specialisms are in the structure and properties of biological active natural compounds from marine invertebrates, especially echinoderms and sponges. His interests include the regulation of secondary metabolism, structural studies of alkaloids, unusual lipids, isoprenoids, polyhydroxysteroids, glycosides of polyhydroxysteroids, steroid, triterpenoid oligoglycosides, carbohydrates and other natural products, as well as the investigation of the biological activities, biosynthesis, chemotaxonomy and chemical evolution of secondary metabolites.

He is the author and co-author of around 500 scientific articles, 4 monographs and 20 patents. To mark the occasion of Professor Valentin Stonik's 80th birthday in December 2022, Dr.

Pavel S. Dmitrenok, Dr.

Natalia V. Ivanchina and Dr.

Vladimir I. Kalinin edited a Themed Issue entitled "Honoring Prof.

Dr. Valentin A.

Stonik for His Outstanding Contribution to Marine Natural Product Chemistry on the Occasion of His 80th Birthday". The contributions are original researches or reviews and cover every aspect of marine natural products chemistry, from studying the chemical structures of new metabolites to the investigation of their biological activities, and the synthesis of biological active natural products and their analogs.

This Issue is a gift to Professor Valentin A. Stonik from his colleagues, friends and world experts in marine natural products chemistry and related disciplines that are thriving in the G.

B. Elyakov Pacific Institute of Bioorganic Chemistry under his supervision.

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