Aspertetronin A and B, two novel tetronic acid derivatives produced by a blocked mutant of Aspergillus rugulosus

Abstract

The structures of aspertetronin A (C₁₆H₂₀O₄) and aspertetronin B (C₁₆H₂₂O₅), metabolites of a mutant strain of Aspergillus rugulosus, have been elucidated. The use of both high-resolution ¹H n.m.r. spectroscopy (220 Mc./sec. and spin decoupling) and ‘element-map’ mass spectrometry have proved determining in establishing that the metabolites are the novel acyltetronic acid derivatives (XXII) and (XXIII) respectively.