The verrucarins and roridins are secondary metabolites of the soil fungi
Myrothecium verrucaria (Albertini et Schweinitz) Ditmar ex Fries and
Myrothecium roridum Tode ex Fries. The species Myrothecium belongs to
the fungi imperfecti, order of Moniliales, family Tubercularia- ceae
(30, 17, 32). The distinction between these and other closely related
fungal species is difficult. It has been studied and discussed by
various authors (82, 16, 55, 75, 62, 43). Myrothecium species are
parasitic on leaves of Gardenia, tomatoes, violets, kidney beans,
snapdragons and other common plants. They are also found on decaying
tissue and in soil. It was known earlier that cultures of the two
species mentioned exhibit cellulolytic properties due to the presence of
a very active cellulase which was used for the treatment of cellulose
during the production of textiles [for leading references see (42,
66)]. The first investigation of the secondary metabolites of these
micro- organisms was carried out by BRIAN and MCGOWAN (16). They
isolated a crystalline compound, designated as glutinosin and assigned
the formula C4sH60016, from cultures of Metarrhizium glutinosum S. Pope,
which in fact is a Myrothecium species (82, 55). Glutinosin exhibited
anti- fungal activity. Eight years later BOWDEN and SCHANTZ (14)
described the isolation and characterization of a dermatitic or
skinirritating crystal- line compound melting at 38°, and possessing the
formula C H 04, 1s 22 from culture filtrates of Myrothecium verrucaria.
They suspected the presence of additional biologically active
substances.