Fig. 3.

Comparison of dqfCOSY spectra obtained for pupal and adult D. catalinae metabolite extracts, illustrating the utility of high-resolution 2D NMR spectra for the comparative analysis of complex metabolite mixtures. (A) 0.8- to 3.4-ppm section of the spectrum obtained for D. catalinae pupae (600 MHz, CD₂Cl₂), illustrating the level of assignment achieved for this sample. Signals were assigned to different compound classes based on detailed analysis of this dqfCOSY plus HMBC and HSQC spectra. Cross-peaks that could be assigned are boxed; solid pink: germacrene-type sesquiterpenoids; dashed pink: humulene-type sesquiterpenoids; dashed black and blue: farnesol; dashed green: fatty acids. Polyketides: blue (8), orange (6 and isomer), green (10), and black (shared signals of 8–10). (B) Corresponding section of spectrum obtained for D. catalinae adults. The spectrum reveals a large number of polyketide fragments different from those observed in the pupae (1–7, boxed red), in addition to terpenoids and lipids similar to those found in A. See SI Appendix for additional detail.