Antibiotically active metabolites from Talaromyces wortmannii, an endophyte of Aloe vera

Endophytes are microbes that colonize the internal tissues of plants without causing any immediate overt negative effects.¹ They are considered as a promising source of new natural drug leads that are of great potential for medicinal and agricultural applications.^{2, 3} For instance, many of the products currently used for human or animal therapy, in animal husbandry and in agriculture, are produced by microbial products, or are derived from them.⁴ Furthermore, with the increasing incidence of drug resistance in human pathogenic bacteria, which are among the major causes of deaths worldwide,^{5, 6} there is an urgent need for new bioactive secondary metabolites.

As part of our ongoing research focused on the discovery of new bioactive natural products from endophytic fungi,^{7, 8} we studied the chemical constituents of the strain Talaromyces wortmanii, which was isolated from healthy tissues of Aloe vera collected in Alexandria, Egypt. Fungi of the genus Talaromyces have been found in solitary, as well as endophytic states in various climates worldwide from terrestrial to marine-influenced environment.⁹ This genus has been investigated by many researchers as it produces a plethora of interesting compounds such as tetraene lactones,⁹ diphenyl ether derivatives and anthraquinones,¹⁰ which show various biological activities ranging from antibiotics to cytotoxins.^{9, 10, 11} In the present study, we report the isolation and structure elucidation of a new atropisomer (1) a new wortmannin derivative (2) and two wortmannin derivatives (3-4) that were hitherto known only as synthetic products, as well as seven known metabolites (5-11). Furthermore, we evaluated the antibiotic activity of the isolated compounds against several pathogenic Gram positive and negative bacteria.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD