Mulberry anthracnose antagonists (iturins) produced by Bacillus amyloliquefaciens RC-2

Bacillus amyloliquefaciens strain RC-2 produced seven antifungal compounds ( 1– 7) secreted into the culture filtrate. These compounds inhibited the development of mulberry anthracnose caused by the fungus, Colletotrichum dematium. Chemical structural analyses by NMR and FAB-MS revealed that all these compounds were iturins (cyclic peptides with the following sequence: l-Asn → d-Tyr → d-Asn → l-Gln → l-Pro → d-Asn → l-Ser → d- β-amino acid →) and compounds 1– 6 are identical to iturins A-2–A-7, respectively. Compound 7 (iturin A-8) is a new iturin, which has a –(CH 2) 10CH(CH 3)CH 2CH 3 group as a side chain in the β-amino acid in the molecule. Bacillus amyloliquefaciens strain RC-2 produced seven antifungal compounds, which inhibit development of mulberry anthracnose caused by the fungus, Colletotrichum dematium. They were all iturins, and one of them had a –(CH 2) 10CH(CH 3)CH 2CH 3 group as a side chain (R) of β-amino acid.