Sceliphrolactam, a polyene macrocyclic lactam from a wasp-associated Streptomyces sp

Area of Science:

• Natural Product Chemistry
• Microbiology
• Mycology

Background:

• Actinomycetes, particularly Streptomyces species, are prolific sources of bioactive natural products.
• The mud dauber wasp, Sceliphron caementarium, harbors associated microorganisms that may produce unique metabolites.
• Antifungal drug resistance in Candida albicans necessitates the discovery of novel therapeutic agents.

Purpose of the Study:

• To isolate and characterize a novel compound from a Streptomyces species associated with Sceliphron caementarium.
• To determine the chemical structure of the isolated compound.
• To evaluate the antifungal activity of the novel compound against drug-resistant Candida albicans.

Main Methods:

• Isolation of sceliphrolactam from Streptomyces sp. using chromatographic techniques.
• Structure elucidation of sceliphrolactam via comprehensive spectroscopic analysis (1D/2D-NMR, MS, UV, IR).
• Antifungal susceptibility testing of sceliphrolactam against amphotericin B-resistant Candida albicans using microdilution methods.

Main Results:

• A previously unreported 26-membered polyene macrocyclic lactam, named sceliphrolactam, was successfully isolated.
• The complete chemical structure of sceliphrolactam was elucidated through detailed spectral analysis.
• Sceliphrolactam demonstrated potent antifungal activity against amphotericin B-resistant Candida albicans with a Minimum Inhibitory Concentration (MIC) of 4 μg/mL.

Conclusions:

• Sceliphrolactam is a novel natural product with promising antifungal properties.
• The discovery of sceliphrolactam highlights the potential of insect-associated microbes as a source of new drugs.
• Sceliphrolactam warrants further investigation as a potential therapeutic candidate against resistant fungal infections.