Synthesis of a new allelopathic agent from the biotransformation of ent-15α-hydroxy-16-kauren-19-oic acid with Fusarium proliferatum

Abstract

The use of kaurane diterpenes as substrates in fungal biotransformation to achieve bioactive compounds has been widely reported. In this work, the natural product kaurenoic acid, a diterpene widely distributed in the plant Kingdom, was chemically converted into ent-15α-hydroxy-kaur-16-en-19-oic acid (1). Substrate 1 was subjected to biotransformation by the fungus Fusarium proliferatum, furnishing a new derivative, ent-2α,15α-dihydroxy-kaur-16-en-19-oic acid (2). The structure of metabolite 2 was deduced on the basis of spectroscopy and MS data. Derivative 2 showed allelopathic activity on germination and growth of root and stem of lettuce (Lactuca sativa), inhibiting 100% of germination and growth of roots and stem, at higher concentration assayed (10 mol/L).

An Overview of Biotransformation and Toxicity of Diterpenes

“…The ent -2 α -hydroxylation of the ent -kaurane diterpene ent -15 α -hydroxy-kaur-16-en-19-oic acid by Fusarium proliferatum produced a metabolite with higher allelopathic activity on the germination and growth of Lactuca sativa [ 73 ].…”

“…The strain Fusarium proliferatum has shown the ability to promote a selective hydroxylation at the C-2 position of ent -kaurane diterpenoids, with high biotransformation yields [ 73 ].…”