Antibiotic HC34 Azacycloeicosa-3,5,10,13,15-pentaen-2-one, 7,11,13,19-tetramethyl-8-[[2,4,6-trideoxy-4-(methylamino)- .beta.-D-ribo-hexopyranosyl]oxy]-, (3E,5E,7S,8S,10E,13E,15E,19S)- NSC641691 Vicenistatin Vicenistatine