A problem in the structure assignment of acremolin C, which is most probably identical with acremolin B

摘要

With the help of chemical shifts computed with density functional theory (DFT), it is demonstrated that the reported experimental 13C NMR data of acremolin C are incompatible with the claimed structure of an N2,3-ethenoguanine with an isopropyl group at C-V. An alternative structure, which is in agreement with both experimental and computed data, presents an isopropyl group at the C-2' position of an N2,3-ethenoguanine and leads to the conclusion that acremolin C is identical with acremolin B.