Out of three most important classes of synthetic insecticides only the carbamates and pyrethroids were known to have ancestors in nature. Now two organophosphates (which are quite good insecticides and very potent acetylcholinesterase inhibitors, e.g. comparable to carbofuran) have been isolated from Streptomyces antibiotices antibioticus strain DSM 1951.
Title: Diethylmesoxalate hydrate, a new irreversible inhibitor of cholinesterases Voss G, Neumann R Ref: Experientia, 35:583, 1979 : PubMed
Bovine erythrocyte acetylcholinesterase and human plasma cholinesterase are irreversibly inhibited by diethylmesoxalate hydrate, the inhibition potency being comparable to that of certian insecticidal organophosphates and carbamates. Insect cholinesterases, however, appear to be much less affected by diethylmesoxalate hydrate. The compound was also found to inhibit the hydrolysis of paraoxon by rabbit plasma A-esterase, but in a reversible mode.
