Bioactive Compounds from Terrestrial Extremophiles

Abstract

Since the 1960s, bioactive secondary metabolites have been isolated and structurally characterized from eubacteria, archaea, and fungi, microorganisms that have adopted strategies to grow in extreme terrestrial environments. This book highlights a myriad of natural products that have been isolated from terrestrial extremophiles, which the authors define as microorganisms found on land as well as in rivers and salterns but exclude those that dwell in water beyond seashores. The isolation and bioactivity of these molecules from the following extremophiles are described: thermophiles, psychrophiles, acidophiles, alkaliphiles, halophiles, xerophiles, epi- or endophytes, as well as metallotolerant, radioresistant, and unclassifiable microorganisms. Quite a few of these secondary metabolites have entered (pre)clinical trials, and their current status in the drug evaluation process is discussed. The authors also describe the isolation of natural products solely produced by endophytes via mutualistic interactions between the host and the crop and raise the argument of whether these metabolites are produced as a result of mutualistic interactions required for survival or epigenetic manipulations of microorganisms cohabiting within the same niche. This book concludes with a discussion of some of the challenges to accessing environments with significant biodiversity and the notion that as ecological niches and biotechnology evolve, extremophiles will also evolve to be continuous, untapped sources of novel drugs and drug leads.

Data on the biological activity of most compounds are provided. If the values were reported in terms of weight per volume, the units were left unchanged. However, to compare biological data of molecules of different molecular weights, we converted units in terms of molarity for true comparisons to be made.