henylalanine was extremely detected in position 1 of Anabaenopeptins isolated from terrestrial strains. Then, freshwater cyanobacteria may be promising biotechnological targets as a consequence of its highest diversity of amino acids in position 1, because the exocyclic residue is important for its inhibitory activity [12,34,45]. With KDM4 drug regards to the variable position three, Anabaenopeptins from freshwater and marine environments displayed a related pattern of amino acid frequencies, Valine (Val) getting probably the most frequent, followed by Ile and L-Methionine sulfone (MetO2). In contrast, terrestrial strains make various AP variants with Ile in position 3, followed by Val and Leu, the latter getting absent within this position on APs detected in aquatic environments. Homotyrosine (Hty) and Homophenylalanine (Hph) will be the most discovered residues in position four among APs from all habitats analyzed, nonetheless, among terrestrial and marine strains Hph is additional predominantly, whilst Hty is commonly observed in APs from freshwater strains. Except for Glycine (Gly) in some Anabaenopeptins from terrestrial strains, each of the other residues in position 5 are N-methylated. APs from non-aquatic cyanobacteria do not harbor homoamino acids inside the fifth position and, also, Asparagine is only detected in a number of these variants in the respective position. In addition to their detection in position five, homoamino acids seem to become much more persistent in position four from these APs analyzed. Position 6 has the highest richness of amino acids amongst AP variants obtained from marine environments, obtaining incorporated 7 unique residues, whilst this position in variants from freshwater habitats have assimilated 9 different amino acids, becoming the second most diverse website. Such heterogeneity within the final position in APs from aquatic strains just isn’t clear, because the first amino acid residue demonstrated to be crucial in Anabaenopeptin interaction towards its enzyme target [12,34,45]. This array of many amino acids detected in position six is not visualized in Anabaenopeptins from terrestrial strains, exactly where Phe was the amino acid a lot more detected, equivalent to those APs from freshwater microorganisms. The identification in the external physicochemical parameters involved inside the regulation of those molecules can help in controlling and assessing their risks [87]. Furthermore, this type of info can enable a better comprehension of their functions in making organisms [27,881]. Microcystins, nodularins, and saxitoxins are among one of the most studied toxins from cyanobacteria, in which their gene ALK2 review clusters can operate independently, being, hence, able to react oppositely when exposed to the exact same conditions [92,93]. The partnership between the gene cluster of Anabaenopeptins with these clusters inside an individual strain isn’t well explored, demanding far more detailed studies by a holistic approach, given that enabling the study of a variety of peptides at the exact same time [89,90]. Anabaenopeptins content per cell is strongly impacted by environmental elements (Figure 9). Tonk and co-workers [27] investigated the impact of light intensity, temperature, and phosphorous concentration around the growth of your cyanobacterium Anabaena sp. 90 as well as its production of Anabaenopeptins A and C amongst some MC variants and with the anabaenopeptilide 90 B. This later belongs to an underexplored group of depsipeptides, which equivalent to the APs has the structure of a ring with a side chain, but without the ureido linkage. Within the phosphorus-limited conditi