Flufuran, an Antifungal 3,5-Disubstituted Furan Produced by Aspergillus flavus Link by Antonio Evidente* a ), Gennaro Cristinzio b ), Biancavaleria Punzo a ), Anna Andolfi a ), Antonino Testa b ), and Dominique Melck c ) a ) Dipartimento di Scienze del Suolo, della Pianta, dellAmbiente e delle Produzioni Animali, Universita ` di Napoli Federico II, IT-80055 Portici (phone: þ 39-081-2539178; fax: þ 39-081-2539186; e-mail: evidente@unina.it) b ) Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Universita ` di Napoli Federico II, IT-80055 Portici c ) Istituto di Chimica Biomolecolare del CNR, Comprensorio Olivetti, Edificio 70, Via Campi Flegrei 34, IT-80078 Pozzuoli A 3,5-disubstituted furan, named flufuran, was isolated from a culture filtrate of a strain of Aspergillus flavus obtained from a chestnut compost created in the same orchard. Flufuran was identified by spectroscopic methods, and its structure was confirmed through the preparation of some key derivatives, also used to test the antifungal activity. At a concentration of 0.2 mg/ml, assayed against three Phytophthora species, pathogenic of some forest and agrarian plants, flufuran and especially its acetyl derivative showed significant antifungal activity. Although flufuran appears to be identical to a fungal metabolite isolated previously from some Polyporus spp., its interesting antifungal activity has never been reported before. Introduction. – In the last 50 years, besides the traditional agrarian practices, pests control has mainly been achieved by using pesticides, herbicides, and insecticides, which are responsible for major environmental pollution, and human and animal health risks. In recent years, there has been a growing interest in the potential use of microbial metabolites as agrochemicals. Microbial metabolites are expected to overcome the problems associated with resistance of pests, and are generally more biodegradable and more environment-friendly than their synthetic counterparts [1] [2]. Fungi are a well- known source of bioactive compounds, and the research for isolation of novel antibiotics and agrochemicals, which blossomed more than 40 years ago, is still very active today. In addition to their potential use as agrochemicals or chemotherapeutics, bioactive compounds are also useful as lead molecules, serving as structural models for the design of new synthetic compounds with higher activity or stability. In particular, these compounds may disclose novel mechanisms of action capable of overcoming the acquired resistance of plant pathogens to known antibiotics. Moreover, the combined use of bioactive natural compounds with biocontrol agents, e.g. , antagonistic yeasts, has been proposed as a profitable approach to achieve additive and/or synergistic effects and provide greater consistency and efficacy for disease control [3] [4]. A soil-born strain of Aspergillus flavus was isolated from a compost pile and created in chestnut orchard as a possible substratum to be used as fertilizer, as well as for fungi selection, and antagonist against several chestnut diseases. CHEMISTRY & BIODIVERSITY – Vol. 6 (2009) 328  2009 Verlag Helvetica Chimica Acta AG, Zürich