To obtain a new antibiotic AB5366 derivative (salt, alkyl ester thereof) exhibiting effective germicidal activity at low concentrations against plant pathogenic fungi, esp. filamentous fungi, causing no chemical injuries on plants, and low in toxicity to mammals.
This new antibiotic AB5366 derivative [salt, alkyl ester (carboxylate) thereof] is expressed by formula I(R1 is OH; R2 is H; R1 and R2 are joined together into hydroxyimino, oxo or an alkoxyimino; R3 is H or sulfonic acid group; R4 is H or an acyl) (e.g. antibiotic AB5366-1 of formula II). One of the compounds of formula I, i.e., the illustrated compound of formula II, is obtained by reducing an antibiotic AB5366 of formula III. The antibiotic AB5366 of formula III can be produced from AB5366 strain (FERM P-14662). This compound of formula I is improved in antifungal activity as compared to that of the compound of formula III. Besides, the new derivatives include antibiotic AB5366-2 of formula IV, antibiotic AB5366-3 of formula V, other antibiotics AB5366-4, AB5366-5, AB5366-6, and antibiotic AB5366-3 methyl ester.
MARUYAMA MASAHITO
TAMAMURA TAKESHI
TEZUKA YASUYUKI
SATO SEI
KUTSUMA SEIICHI
TAKEUCHI TOMIO
