Expanding the\nDiversity of the Cyanobacterial Dialkylresorcinol\nBartoloside Family

The cyanobacterial dialkylresorcinol\nbartolosides were\ninitially\nreported to feature glycosylated and halogenated moieties. Later,\nbiosynthetic and <i>in vitro</i> studies showed that the\nchlorinated alkyl chains are utilized for a nucleophilic substitution\nwith free fatty acid carboxylates from primary metabolism, generating\nbartoloside esters. Here, we applied a workflow based on PCR screening\ncoupled to LC-HRESIMS and molecular network analysis with the aim\nof discovering additional bartoloside diversity. We report the annotation\nof 27 bartoloside and bartoloside ester derivatives, including the\ncharacterization of two new bartolosides, underlining the breadth\nof structures generated by bartoloside biosynthetic pathways. Some\nof the herein reported bartolosides feature hydroxylation in their\nside chains, a modification that has not been associated with this\nmetabolite family.