Unequivocal identification of two-bond heteronuclear correlations in natural products at nanomole scale by i-HMBC.

ABSTRACT: HMBC is an essential NMR experiment for determining multiple bond heteronuclear correlations in small to medium-sized organic molecules, including natural products, yet its major limitation is the inability to differentiate two-bond from longer-range correlations. There have been several attempts to address this issue, but all reported approaches suffer various drawbacks, such as restricted utility and poor sensitivity. Here we present a sensitive and universal methodology to identify two-bond HMBC correlations using isotope shifts, referred to as i-HMBC (isotope shift detection HMBC). Experimental utility was demonstrated at the sub-milligram / nanomole scale with only a few hours of acquisition time required for structure elucidation of several complex proton-deficient natural products,

SUBMITTER: Wang Y 

PROVIDER: S-EPMC10070429 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature