Favret M E, Paschal J W, Elzey T K, Boeck L D
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285.
J Antibiot (Tokyo). 1992 Sep;45(9):1499-511. doi: 10.7164/antibiotics.45.1499.
The biosynthetic origin of antibiotic A10255 was investigated using 14C- and 13C-labeled amino acids. DL-[1-(13)C]Serine labeled 15 of the 17 amino acid residues present in A10255G. These included the oxazole, thiazole, dehydroalanine, masked glycine, masked alanine and pyridine moieties. The same 15 residues labeled by serine were labeled by [2-(13)C]glycine, apparently by conversion of the glycine to [2,3-(13)C]serine. Formation of the pyridine ring occurred via a C3 to C3 condensation of two serines. The results indicated origin of the masked alanine from alanine; the masked glycine from glycine; the thiazole residues from cysteine; and the threonine, masked dehydrobutyrine, masked dehydronorvaline and masked dehydroleucine residues from threonine. L(-)[CH3-(13)C]Methionine labeled the methyl carbon of the masked dehydronorvaline moiety in factor B and the two methyl carbons of the masked dehydroleucine moiety in factor E. The results demonstrate that A10255 originates exclusively from amino acids in a manner similar to the closely related thiopeptide antibiotics nosiheptide and thiostrepton.
利用¹⁴C和¹³C标记的氨基酸研究了抗生素A10255的生物合成起源。DL-[1-(¹³)C]丝氨酸标记了A10255G中17个氨基酸残基中的15个。这些残基包括恶唑、噻唑、脱氢丙氨酸、掩蔽甘氨酸、掩蔽丙氨酸和吡啶部分。被丝氨酸标记的这15个相同残基也被[2-(¹³)C]甘氨酸标记，显然是通过甘氨酸转化为[2,3-(¹³)C]丝氨酸实现的。吡啶环的形成是通过两个丝氨酸的C3到C3缩合反应。结果表明，掩蔽丙氨酸起源于丙氨酸；掩蔽甘氨酸起源于甘氨酸；噻唑残基起源于半胱氨酸；苏氨酸、掩蔽脱氢丁酸、掩蔽脱氢正缬氨酸和掩蔽脱氢亮氨酸残基起源于苏氨酸。L(-)[CH₃-(¹³)C]甲硫氨酸标记了因子B中掩蔽脱氢正缬氨酸部分的甲基碳以及因子E中掩蔽脱氢亮氨酸部分的两个甲基碳。结果表明，A10255完全以类似于密切相关的硫肽抗生素诺西肽和硫链丝菌素的方式起源于氨基酸。
