STRUCTURE OF MINOSAMINOMYCIN Sir: Minosaminomycin is an antibiotic isolated from a culture filtrate of Streptomyces No. MA514-A1 related to Actinomyces aureomonopo- diales, and inhibits growth of mycobacteria.1) We report on its structural elucidation

partial synthesis.* Minosaminomycin1) (I) has the formula C25H46N8O10 (derived from the elemental analysis, titration equivalent and carbon-13 spectrum**) and the following properties; mp 225260°C (dec); [a]22D+30° (c 1.0, water); pKa' 2.9, 6.2, 8.1 and > 12; uv end absorption; it (KBr) 3400, 2950, 1690, 1655, 1570, 1440, 1400, 1340, 1300, 1120, 1050, 1010, 970, 710 cm-1; positive ninhydrin, RYDON-SMITH and pentacyanoaquoferriate; negative SAKAGUCHI, diacetyl and red tetrazolium. The pmr (D2O, TMS as external reference) of I shows the presence of an isobutyl group (8 1.38, 6H, dd and 61.9-2.2, 3H), a characteristic methyl group (S 1.72, d), an anomeric proton (6 5.45, d), two methylene protons (o 2.35 and 2.55) and 14 other protons (d 3.2-4.9). A new aminocyclitol, 1D-1-amino-1-deoxymyo-inositol 1) (II) was isolated in good yield by acid hydrolysis (6 N HCI, reflux for 5 hours) of I, together with a hydantoin derivative (III), a sugar derivative (IV) and a trace of leucine and a basic glycoside named minobiosamine (V). Alkaline hydrolysis of I with saturated aqueous Ba(OH)2 (reflux for 4 hours) followed by column chromatography on Amberlite CG-50 (NH4+) resin afforded V in 32 % yield, mp 126-128°C (dec); [a]29D+81° (c 0.8, water) ; pKa' 6.7, 7.9 and 9.0. The pmr of V was compared with that of kasuganobiosamine2) (VI) obtained from kasugamycin and suggested the presence of the kasugamine moiety (1'-H, 6 5.38, d; 2'-H, 6 3.60; 3'-H2, 6 2.26; 4'-H, 8 3.25; 5'-H, 8 4.45; 6'-H3, d 1.72, d). Acid hydrolysis (6 N HCl at 105°C for 20 hours in a sealed tube) of V gave II and IV***. Benzyloxycarbonylation of V by the usual SCHOTTEN-BAUMANN procedure gave tri-Nbenzyloxycarbonylminobiosamine (VII) in 85 % yield, mp 171-172'C, [a]24D+33' (c 1, dimethylformamide). Treatment of VII with NaH in dimethylformamide afforded a cyclic carbamate3) of di-N-benzyloxycarbonylminobiosamine which was hydrolyzed with 5 % Ba(OH)2 .8H2O solution in 50 % aqueous dioxane (80°C for 6 hours) to afford di-N-benzyloxycarbonylminobiosamine (VIII) in 49 % yield from VII, mp 123-126°C (dec); [a]D+43° (c 1, dimethylformamide). Periodate oxidation of VIII in a mixture of 0.1 M sodium acetate buffer (pH 5.4) and ethanol (1: 1 in volume) at room temperature for 97.5 hours gave crystalline di-Nbenzyloxycarbonylkasugamine (44 % yield, mp 155-156°C [a]24D) +36° in pyridine) which was treated with 1.3 % HCl in methanol at room temperature for 24 hours to afford an anomeric mixture of methyl di-N-benzyloxycarbonylkasugaminide. The anomeric mixture was separated into aand (3-anomers ([a]28D+21° and [a]28D-23' in chloroform, respectively) by silica gel chromatography developed with a mixture of benzene and acetone (20:1 in volume). They were identical with methyl di-N-benzyloxycarbonyl-aand (3-kasugaminide derived from di-N-benzyloxycarbonylkasuganobiosamine in all respects.