Endogenous phthalates as a prospective regulator of interspecific relations in a biocoenosis

Abstract

It is widely believed that phthalates are xenobiotic pollutants whose prevalence in the environment is associated with their facilitated diffusion from plastic materials. Studies into the effect of synthetic phthalates on living organisms revealed their extremely negative action on the metabolism of animals and humans. The acting mechanism of these compounds is realised through a ligand-receptor pathway. Along with dioxins, polychlorinated biphenyls and similar compounds, phthalates are classified as endocrine disrupters. However, at present, sufficient evidence has been accumulated confirming the natural origin of phthalates. Thus, phthalates were de novo biosynthesised from labelled precursors in an algae culture. These compounds were detected in closed experimental systems, including cell cultures of highest plants, as well as those isolated from a number of bacterial, fungi, lowest and highest plant forms located far from the sources of technogenic pollution. The concept of phthalate biogenesis assumes the action of these compounds on living systems. Phthalates exhibit bactericidal and fungicidal action and compose allelopathic exudates, suppressing the growth of competing plant forms. Phthalates possess insecticidal and repellent properties. An analogy can be traced between the action of phthalates and endocrine disrupters of another chemical category, namely phytoestrogens, which regulate herbivorous mammal populations. A hypothesis is proposed about the biological role of endogenous plant phthalates representing secondary metabolic compounds. Exhibiting predominantly a shielding function, these compounds participate in the network of interactions between plants, animals, fungi and microorganisms. It should be noted that synthetic and endogenous phthalates are characterised by essential stereochemical differences, which can explain their different action on living organisms.

First Data on PAE Levels in Surface Water in Lakes of the Eastern Coast of Baikal

“…PAEs are usually considered to be industrial pollutants, exogenous substances that are hazardous to humans, but recently there has also been evidence of their biogenic origin. PAEs are reported to possess allelopathic, antimicrobial, insecticidal, and other biological activities, which might enhance the competitiveness of plants, algae, and microorganisms to better accommodate biotic and abiotic stress [20,47]. These compounds have been found in red [48] and freshwater algae, cyanobacteria [49], fungi [50], and higher plants of various families.…”

Diesters of o-Phthalic Acids in Surface Waters with Background Level of Pollution: Concentrations Levels, Distribution, Sources, and Environmental Risk (Lake Baikal, Russia)

“…Water bodies pollution with household plastic is considered as one of probable PAEs sources in aquatic environment. However, as it was shown in model experiments [15], colonies of microorganisms, which recycle PAEs incoming from plastic develop in water bodies on plastic surfaces. As rates of PAEs diffusion and biodegradation are comparable, only a part of their amount diffuses into water.…”

“…Six PAEs: di-methyl phthalate (DMP), di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DOP) are considered as priority ones and are to be permanently controlled in the environment. It is shown at the same time that PAEs possess an allopathic activity, antimicrobial and insecticide properties, which increase competitiveness of plants, algae and microorganisms [15].…”

Case Study of Diesters of o-Phthalic Acid in Surface Waters with Background Levels of Pollution

“…Recent studies suggest a probable biosynthesis of PAEs by different plants, freshwater algae, cyanobacteria, and fungi [15]. PAEs are reported to possess allopathic activity and antimicrobial and insecticide properties, which increase the competitiveness of plants, algae, and microorganisms [19]. PAEs detected in surface water at trace levels are evidently related not just to anthropogenic pollutants, as they can accumulate from both abiogenic and biogenic sources, and the contributions of these two may be comparable in magnitude.…”