Carbon-13 Fourier Transform Nuclear Magnetic Resonance. IX. Complete Assignments of Some Prodigiosins. Bioincorporation of Label

A comprehensive study has been made of the carbon-13 chemical shifts of substituted pyrroles. The data, together with perdeuteration, single resonance, and off-resonance techniques, formed the basis for the complete interpretation of the carbon-13 spectra of the prodigiosins. Based on these assignments the biosynthetic origin of the prodigiosin carbons was elucidated, with further biosynthetic studies to be reported.Carbon-13 chemical shifts are shown to be an effective means of determining sites of protonation.