Division of Agriculture and Agricultural Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Magn Reson Chem. 2009 Oct;47(10):814-8. doi: 10.1002/mrc.2496.
An efficient pulse sequence for measuring long-range C-H coupling constants (J(C-H)) named selective J-resolved HMBC has been developed by replacing a (1)H 180 degrees pulse with a selective (1)H 180 degrees pulse and the HMBC pulse scheme with the constant time (CT) HMBC employed in the J-resolved HMBC pulse sequence that we reported previously. The novel pulse sequence providing only long-range J(C-H) cross peaks for easy and accurate analysis enables to overcome disadvantages of the previous HMBC-based pulse sequences (J-resolved HMBC-1) along with maintaining high sensitivity. The efficiency of measuring long-range J(C-H) using the proposed pulse sequence has been demonstrated in applications to the complicated natural products, portmicin and monazomycin.
一种名为选择性 J 分辨 HMBC 的高效脉冲序列，用于测量长程 C-H 耦合常数 (J(C-H))，通过用选择性 1H 180 度脉冲替换 1H 180 度脉冲，并将 HMBC 脉冲方案替换为我们之前报道的 J 分辨 HMBC 脉冲序列中使用的恒时 (CT) HMBC 来开发。新的脉冲序列仅提供远程 J(C-H) 交叉峰，便于轻松准确地分析，能够克服以前基于 HMBC 的脉冲序列（J 分辨 HMBC-1）的缺点，同时保持高灵敏度。该提议的脉冲序列在对复杂天然产物（portmicin 和 monazomycin）的应用中，证明了测量远程 J(C-H) 的效率。
