High‐effective biosynthesis of baccatin Ⅲ by using the alternative acetyl substrate, N‐acetyl‐ d ‐glucosamine

Aims Paclitaxel is a type of broad‐spectrum anticancer drug in short supply. The price of acetyl‐CoA (17 709 677·4 USD mol −1 ), which is the acetyl group donor for the enzymatic synthesis of the intermediate, baccatin Ⅲ, is still the bottleneck of the mass production of paclitaxel. This study reports a novel acetyl group donor, which could substantially reduce the cost of production. Methods and Results In this study, a substrate spectrum with 14 kinds of representative acetyl‐donor substitutes predicted by computer‐aided methods was tested in a 10‐deacetylbaccatin Ⅲ‐10‐ O ‐acetyltransferase (DBAT) heterogeneous‐expressed open‐whole‐cell catalytic system. The results of computer prediction and experimental analysis revealed the rule of the acetyl‐donor compounds based on this substrate spectrum. N‐acetyl‐ d ‐glucosamine (30·95 USD mol −1 , about 572 202‐fold cheaper than acetyl‐CoA) is selected as a suitable substitute under the rule. The yield when using N‐acetyl‐ d ‐glucosamine as acetyl donor in open‐whole‐cell catalytic system was 2·13‐fold of that when using acetyl‐CoA. In the in vivo system, the yield increased 24·17%, which may indicate its cooperation with acetyl‐CoA. Conclusion The success of open‐whole‐cell synthesis and in vivo synthesis of baccatin Ⅲ by adding N‐acetyl‐ d ‐glucosamine as acetyl substrate demonstrates that it is a useful substrate to improve the yield of baccatin Ⅲ. Significance and Impact of the Study All these findings provided a potential acetyl‐donor substitute for acetyl‐CoA, as well as a low cost and efficient method of preparing paclitaxel through baccatin Ⅲ semi‐synthesis.