Chemistry,Biosynthesis,and Biological Activity of Halogenated Compounds Produced by Marine Microorganisms

Natural products derived from marine microorganisms have been received great attention as a potential source of new compound entities for drug discovery.The unique marine environment brings us a large group of halogen-containing natural products with abundant biological functionality and good drugability.Meanwhile,biosynthetically halogenated reactions are known as a significant strategy used to increase the pharmacological activities and pharmacokinetic properties of compounds.Given that a tremendous increase in the number of new halogenated compounds from marine microorganisms in the last five years,it is necessary to summarize these compounds with their diverse structures and promising bioactivities.In this review,we have summarized the chemistry,biosynthesis(related halogenases),and biological activity of a total of 316 naturally halogenated compounds from marine microorganisms covering the period of 2015 to May 2021.Those reviewed chlorinated and brominated compounds with the ratio of 9:1 were predominantly originated from 36 genera of fungi(62%)and 9 bacterial strains(38%)with cytotoxic,antibacterial,and enzyme inhibitory activities,structural types of which are polyketides(38%),alkaloids(27%),phenols(11%),and others.This review would provide a plenty variety of promising lead halogenated compounds for drug discovery and inspire the development of new pharmaceutical agents.

Nonmetallic modified zero-valent iron for remediating halogenated organic compounds and heavy metals: A comprehensive review

Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.