TABLE 1.

13C NMR data for synthetic 4-hydroxy-2-heptylquinoline and the main components of the biosynthetic product after feeding with doubly labeled [13C]acetatealegend

CarbonShift(s) (ppm)Multiple 13C satellitedJcc (Hz) (±0.5)
4-Hydroxy- 2-heptylquinolinebMain componentsc
C-2157.1157.1d44.3
C-3108.8108.8s
C-4180.7180.7s
C-4a125.5125.5s
C-5126.0126.0s
C-6125.0125.0s
C-7133.4133.4s
C-8119.0119.1s
C-8a141.6141.6s
C-935.035.0d44.3
C-1030.130.1-30.8
C-1130.2e30.1-30.8
C-1230.1e30.1-30.8
C-1332.832.8d34.1
C-1423.623.68, 23.62fd, d34.6, 34.1
C-1514.314.41, 14.39, 14.35fd, d35.1, 35.6, 35.1
  • a As determined by the MS analysis, the main components are a mixture of several compounds, the main components of which are the heptyl and nonyl derivatives. The structure of one heptyl derivative in the tautomeric keto form is

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  • b The signals were unambiguously assigned from correlations in the two-dimensional HMBC spectrum.

  • c Overlap of signals prevented assignment of the internal chain carbons in the main components.

  • d Doublet 13C satellite signals centered on the shift of the major signal were observed for the signals indicated by “d” but not for the signals indicated by “s”.

  • e The assignments are interchangeable.

  • f End units from major components of the mixture.