Discovery and antibacterial activity of glabramycin A|[ndash]|C from Neosartorya glabra by an antisense strategy

Treatment of drug-resistant bacteria is a significant unmet medical need. This challenge can be met only by the discovery and development of new antibiotics. Antisense technology is one of the newest discovery tools that provides enhanced sensitivity for detection of antibacterials, and has led to the discovery of a number of interesting new antibacterial natural products. Continued utilization of this technology led to the discovery of three new bicyclic lactones, glabramycins A–C, from a Neosartorya glabra strain. Glabramycin C showed strong antibiotic activity against Streptococcus pneumoniae (MIC 2 μg ml−1) and modest antibiotic activity against Staphylococcus aureus (MIC 16 μg ml−1). The isolation, structure, relative configuration and antibacterial activity, and plausible biogenesis of these compounds have been discussed.