Isolation and Characterisation of Toxic Secondary Metabolites Produced by Black Mould
Microbial secondary metabolites, commonly called natural products, have been crucial for the progression of modern medicine. Not essential for the basic functions of life, secondary metabolites are instead produced to provide a competitive advantage in the environment. The method of action is commonly toxicity to other species in their environment, thereby harming or killing the competition. These toxic properties have allowed them to be utilised as antimicrobial and antitumor agents, however this same toxicity is able to cause detrimental health effects in humans causing symptoms ranging from minor to life threatening. The black mould Stachybotrys chartarum is capable of producing very toxic secondary metabolites called macrocyclic trichothecenes. Satratoxin G (6) and H (7), are two of the most toxic naturally occurring compounds in the world. This has made S. chartarum a common target when adverse health has been associated with damp and mouldy dwellings. However, there is very little evidence for this link beyond its ubiquity and ability to produce the aforementioned highly toxic macrocyclic trichothecenes. This research investigates S. chartarum and the toxic secondary metabolites it produces, with special emphasis on satratoxin G and H. Different culturing methods and resulting morphology are assessed. The satratoxins were isolated from crude extracts and full characterisation by 1-D and 2-D NMR spectroscopy was done. This process revealed differences from the accepted literature, and spectra are reported herein to aid in future identification. The importance of genetics and the public health implications of mould contamination are also discussed.