Meliponamycins: Antimicrobials from Stingless Bee-Associated Streptomyces sp.

Abstract

Social insects establish complex interactions with microorganisms, some of which play defensive roles in colony protection. The important role of pollinators such as the stingless bee Melipona scutellaris in nature encouraged us to pursue efforts to study its associated microbiota. Here we describe the discovery of two novel cyclic hexadepsipeptides, meliponamycin A (1) and meliponamycin B (2), from Streptomyces sp. ICBG1318 isolated from M. scutellaris nurse bees. Their structures were established by interpretation of NMR and MS data, and the absolute configuration of the constituent amino acids was determined by the advanced Marfey's method. Compounds 1 and 2 showed strong activity against the entomopathogen Paenibacillus larvae and human pathogens Staphylococcus aureus and Leishmania infantum. Actinobacteria were recovered from M. scutellaris bees.Micromonospora sp. ICBG1321 and Streptomyces sp. ICBG1323 produced several anthracyclines and lobophorins, respectively, some of them with strong inhibitory activity against P. larvae. 17 Streptomyces sp. ICBG1318 was isolated from the cuticle of M. scutellaris nurse bees and showed activity against P. larvae in antagonistic assays. 17 Here we describe the isolation, structural

Chemical Ecology in Insect-microbe Interactions in the Neotropics

“…The novel cyclodepsipeptides named meliponamycin A (40) and meliponamycin B (41) (▶ Fig. 3) were strongly active against P. larvae and human pathogens, such as Staphylococcus aureus and L. infantum [92].…”

Structural Revision of Lydiamycin A by Reinvestigation of the Stereochemistry

“…The elution order of the Marfey’s products of piperazic acid was empirically reported in a structural study of the piperazic acid-bearing cyclic peptide dentigerumycin, with authentic l - and d -piperazic acids; the l -Marfey’s product of ( R )-piperazic acid elutes faster than the d -Marfey’s product, whereas the d -Marfey’s product of ( S )-piperazic acid elutes before the l -Marfey’s product by reversed-phase HPLC. Since this first report of Marfey’s analysis of piperazic acids, this elution order has been widely used for the configurational determination of piperazic acid moieties in natural products. − …”

Lenzimycins A and B, Metabolites With Antibacterial Properties From Brevibacillus sp. Associated With the Dung Beetle Onthophagus lenzii

“…It has also been reported that the symbiotic Streptomyces bacteria, located in specialized antennal glands, excrete antibiotics to protect wasp larvae from pathogenic fungal infestation (Kaltenpoth et al, 2005;Kroiss et al, 2010). Furthermore, studies have shown that the stingless bees, Melipona scutellaris, engage in defensive symbiosis with actinobacteria that produce antibacterial small molecules including the lobophorin, anthracycline, and cyclic hexadepsipeptide families, helping to protect their colonies against the entomopathogenic Paenibacillus larvae (Rodríguez-Hernández et al, 2019;Menegatti et al, 2020).…”