title: BASHD-J-resolved-HMBC, an efficient method for measuring proton-proton and heteronuclear long-range coupling constants.
abstract: Natural products often possess various spin systems consisting of a methine group directly bonded to a methyl group (e.g. -CHa-CHb(CH3)-CHc-). The methine proton Hb splits into a broadened multiplet by coupling with several vicinal protons, rendering analysis difficult of (n)JC-H with respect to Hb in the J-resolved HMBC-1. In purpose of the reliable and easy measurements of (n)JC-H and (n)JH-H in the aforesaid spin system, we have developed a new technique, named BASHD-J-resolved-HMBC. This method incorporates band selective homo decoupled pulse and J-scaling pulse into HMBC. In this method, high resolution cross peaks can be observed along the F1 axis by J-scaling pulse, and band selective homo decoupled pulse simplified multiplet signals. Determinations of (n)JC-H and (n)JH-H of multiplet signals can easily be performed using the proposed pulse sequence.
authors.affiliation: Division of Agriculture and Agricultural Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Furihata
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Tashiro
mesh_terms: D000465:Algorithms; D001554:Benzene / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D012815:Signal Processing, Computer-Assisted
chemical_list: D011522:Protons; D001554:Benzene
keywords: BASHD; BASHD-J-resolved HMBC; J-resolved HMBC; heteronuclear long range coupling constants; selective J-resolved HMBC