Ultra-high resolution band-selective HSQC for nanomole-scale identification of chlorine-substituted ¹³ C in natural products drug discovery.

ABSTRACT: Ultra-high resolution band-selective HSQC (bsHSQC) has been employed for detection of ³⁵ Cl-³⁷ Cl isotope shifted ¹³ C NMR signals for assignment of regioisomerism in bromo-chloro natural products. Optimum pulse sequence and instrumental parameters for maximization of detection of the isotope shifts were explored. The chlorine isotope shifts (Δδ) were detected within crosspeaks and were shown to vary with hybridization of ¹³ C, substitution of ¹³ C, presence of β-chloro substituents, and their relative configuration. Deconvolution of Cl-substituted CH bsHSQC crosspeaks may provide other useful information, including a potentially MS-independent method for quantitating ³⁷ Cl/³⁵ C isotopic fractionation during the b

SUBMITTER: Wang X 

PROVIDER: S-EPMC6411301 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature