Mycopathologia 130: 179-184, 1995. 179 (~) 1995 Kluwer Academic Publ&hers. Printed in the Netherlands. Production of neosolaniol by Fusarium tumidum Claudio Altomare 1, Alberto Ritieni 2, Giancarlo Perrone 1 , Vincenzo Fogliano 2, Luisa Mannina 3 & Antonio Logrieco 1 l lstituto Tossine e Micotossine da Parassiti Vegetali, CNR, Bari, Italy; 2Dipartimento di Scienza degli Alimenti, Universit3 di Napoli 'Federico H' , Portici, Italy; 3CNR, Area della Ricerca, Montelibretti, Roma, Italy Received20 May 1994; acceptedin revisedform 22 March 1995 Abstract Extracts from autoclaved maize culture of Fusarium tumidum strain R-5823 were toxic towards Artemia salina. Bioassay-guided fractionation of the organic extract led to the isolation of the toxic compound that was identified as the trichothecene toxin neosolaniol (NEOS) by 1H, 13C nuclear magnetic resonance spectroscopy and low- resolution electronic impact mass spectrometry. The amount of NEOS produced by the strain R-5823 was 300 mg/kg maize culture. NEOS was also detected by HPLC in cultures of four out of seven additional strains of F. tumidum and Gibberella tumida with different origin, in amounts ranging from 1 to 311 mg/kg. This is the first report on the production of a trichothecene toxin by F. tumidum. Key words: Fusarium tumidum, Mycotoxins, Neosolaniol, Trichothecenes Introduction The species Fusarium tumidum Sherb. was constituted in 1928 by Sherbakoff [1 ], based on specimens collect- ed from decaying or dried pods of Broom (Sarotham- nus (=Cytisus) scoparius Wimm.) in Germany. Fusar- ium tumidum has been treated as synonymous with F. solani (Mart.) Appel & Wollenw. emend. Snyd. & Hans., F. culmorum (W.G. Smith) Sacc. and other Fusarium species [2, 3]. Recently, the teleomorph of F. tumidum, described as Gibberella tumida Broadh. & Johnst., has been found in New Zealand, occurring as the causal agent of a disease of Gorse (Ulex europaeus L.) [4]. A possible use of this fungus as mycoherbicide against both Gorse and Broom in plantation forests has been proposed [5]. Because of the varying species concept in the treat- ment of F. tumidum and scarce availability of type strains, the knowledge about biology of this species appears to be lacking [3, 6]. We considered it useful to investigate on production of toxic metabolites by F. tumidum, especially in the perspective of a possible use for biocontrol of weeds. This note reports the isolation and identification of the trichothecene toxin neosolan- iol (NEOS) (Fig. 1) in cultures of various strains ofF. H C 16 3 . O OH 13~1 UH I 1 I 114 OCOCH 3 [is CH3 OCOCH 3 Fig. 1. Structure of neosolaniol. tumidum and G. tumida. A morphological and cultur- al characterization of the toxigenic strain R-5823 was also carried out and results are reported herein. Materials and methods Fungal isolates. The geographical origin, source and accession numbers of the isolates ofF. tumidum and G. tumida investigated in this study, are given in Table 1. The strain R-5823 (=NRRL 13394, BBA 63572, CBS 486.76) was provided from the Collection of the North-