Hydroxyaspergillic acid

A closely related product from A. flavus, named hydroxyaspergillic acid, may be separated from aspergillic acid by use of organic solvents (34). Elemental analysis ascribed the aspergillic structure plus one oxygen... 

Separated from hydroxyaspergillic acid, with which it crystallizes, by counter-current extraction. Yield of 50 mg from 4 g crude hydroxyaspergillic acid. Produced by A. oryzae. Active vs hiochi bacteria. 

These are closely related to aspergillic acid. Neo-aspergillic acid (75, 78), 3,6-diisobutyl-2-hydroxypyrazinc-1 -oxide, and neo-hydroxyaspergillic acid, the latter optically active, are known (144). 

Hydroxyaspergillic acid (H 6), l-hydroxy-6-(l-hydroxy-l-methylpropyl)-3-isobutyl-2(l//)-pyrazinone, an Aspergillus sp metabolite.727... 

The following pA values have been measured 3-methoxypyrazine 1-oxide, — 0.45 (745) aspergillic acid, 5.5 (94) and hydroxyaspergillic acid, 4.9 (94). P.m.r. measurements have shown that 2-methoxypyrazine 1,4-dioxide protonates at N-4 (1136). 

The location of the additional oxygen atom of hydroxyaspergillic acid (4), 12 20 203. was ascertained to be on the jec-butyl side chain from the following results (79) (Scheme 2). Reduction with HI in AcOH affords the de-hydrodeoxy derivative (5) which becomes optically inactive. The UV spectrum indicates that a newly generated double bond is connected to the pyrazine ring. Ozonolysis of 5 yields acetaldehyde and 6, which gives a positive iodoform reaction. 

Aspergillic Acid an Antibiotic Substance Produced by Aspergillus flavus. III. The Structure of Hydroxyaspergillic Acid. J. Biol. Chem. 232, 785 (1958). 

Nakamura, S., Y. Kurimura, and T. Shiro Growth inhibition of hiochi-bacteria, specific saprophytes of sake. IX. The production of hydroxyaspergillic acid. Nippon N6gei-kagaku Kaishi 35, 1058 (1961) — Chem. Abstr. 60, 14855g (1964). 

---