668-72-4Relevant academic research and scientific papers
UNIQUE 1'-O-BOC PROTECTION OF VIRGINIAMYCIN S AND RESULTING RESISTANCE AGAINST SODIUM HYDROXIDE
Moerman, Marc C.,Anteunis, Marc J. O.
, p. 647 - 652 (2007/10/02)
The picolinic hydroxyl in Virginiamycin S1 (VS%1; 1a) can be protected with di-tert-butyloxycarbonate affording the tert-butyloxycarbonyl derivative thus yielding VS1-1'-O-Boc (1b) in a fast and quantitative conversion without concomitant betaine (1c) formation.Once protected however, the lactone bond in 1b can no longer be cleaved under mild alkaline conditions.A possible explanation is given.
THE DEPENDENCE OF ENDOPEPTOLYSIS ON THE SEQUENTIAL CHIRALITY EXEMPLIFIED BY A SIMPLIFIED PREPARATION OF THE 4>-EPIMER OF VIRGINIAMYCIN S.
Anteunis, M. J. O.,Auwera, C. van der,Sharma, N. K.
, p. 183 - 186 (2007/10/02)
The 4-epimer of Virginiamycin S (VS-epi4) containing the heterochiral triad L-Pro3-D-MePhe4-L-(γOxo)Pec5 is found to be resistant against acidic hydrolysis in contrast to the native VS possessing the L3,L4,L5-sequence.This allows a simplified protocol for its isolation, and exemplifies previous findings (ref. 1) about the easy endopeptolysis of homochiral triads.
A SEARCH FOR PHENOLIC PROTECTION IN VIRGINIAMYCIN S
Sharma, N.K.,Anteunis, M.J.O.
, p. 463 - 480 (2007/10/02)
In order to be able to mask the hydroxyl grouping of the pipecolic acid residue in Virginiamycin during alkaline (NaOH) and acidic (Tfa) break-down procedures and to use peptidic fragments coming thereof for further reconstitution by classical peptide synthesis procedures, we have investigated several candidates for protection/deprotection.Thus the phenacyl derivatives (4 and 5), the allyloxycarbonyl derivative (6), the trichloroethyloxycarbonyl derivatives (8 and 9) and the 2,4-dinitrophenyl derivative (10) have been prepared.Among these none were stable in aqueous basic conditions.The Alloc- (6) the Troc- (8) and Dnp-derivative (10) may have some applications under acidic conditions.
