Pharmaceutica Analytica Acta

A new enniatin antibiotic from the endophyte Fusarium tricinctum Corda

5^th International Conference and Exhibition on Pharmaceutics & Novel Drug Delivery Systems

March 16-18, 2015 Crowne Plaza, Dubai, UAE

Ahmed M Zaher Shaekhon

Posters & Accepted Abstracts: Pharm Anal Acta

Abstract:

Enniatins (ENs) are antibiotics produced by the fungal genera of Fusarium, Halosarpheia, Verticillium and Alternaria. The ENs are biosynthesized from three molecules of N-methyl-L-amino acids and three molecules of D-α-hydroxyisovaleric acid to form an18-membered cyclic depsipeptide. ENs exhibit their antibiotic, herbicidal and insecticidal activities by disrupting the ion selectivity of the cell walls. They are capable of forming stoichiometric complexes with various cations facilitating the transport of the latter through biological membranes (especially the mitochondrial membranes resulting in uncoupling of oxidative phosphorylation). Another reported mechanism for the insecticidal activity of ENs involves their capacity to inhibit the acyl-CoA:cholesterol acyltransferase activity. The endophyte F. tricinctum Corda was isolated from the fruits of Hordeum sativum Jess. and was grown on a rice medium and incubated at 25?C for 21 days. The dried methanol extract of fungal metabolites was analyzed by LC-MS. The LC separation of the fungal secondary metabolites was achieved employing a ZORBAX Eclipse XDB-C18 column (5 μm, 4.6x150 mm) (Agilent Technologies, New Castle, DE, USA). LC-MS and LC-MS/ MS analysis of the methanol extract led to the identification of six enniatin antibiotics (A, A1, A2, B, B1 and B2). This study reports enniatin A2 as a new EN analogue and enniatin B2 is reported here for the first time in the endophyte. The methanol extract of ENs showed promising antibacterial, antifungal, and antimalarial activities. The methanol extract showed also mild antileishmanial activity against Leishmania donovani ATCC 39930D with IC50 value=16.96 μg/ml and IC90 value=30.4 μg/ml.