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

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 (10-4 mol/L).

Biological screening of Annonaceous Brazilian Medicinal Plants using Artemia salina (brine shrimp test)

Eighteen different extracts from five Annona species collected in Minas Gerais state, Brazil, were submitted to the brine shrimp lethality test in order to detect potential sources of novel cytotoxic, antitumor, pesticidal and anti-Trypanosoma cruzi compounds. All of the Annonaceous species tested showed good larvicidal activity as compared to a reference compounds and literature data.