| Summary: | Recently developed 1H nuclear magnetic resonance methods, including 2-dimensional, 1H-detected-[13C] shift correlation spectroscopy and 1-dimensional HOHAHA spectroscopy at 500 MHz have been used to identify the major bile acid in the serum of rats treated with alpha-naphthylisothiocyanate as the taurine conjugate of 3 alpha,6 beta,7 beta-trihydroxy-5 beta,22-cholen- 24-oic acid (tauro-delta 22-beta-muricholate), a derivative of beta-muricholate having an unsaturated bond in the acyclic side chain. Complete stereospecific assignments of the 1H and protonated 13C spectra of the title compound and beta-muricholate are reported. The assignments were based entirely on 1H-1H and 1H-13C scalar connectivities and were made using approximately 0.5-2.0 mg of material. It is suggested that these new methods will be of general value for identifying the structure and assigning the spectra of other scarce steroid-like molecules.
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