FIGURE 4.

Relative tetritol catabolism in vivo at low temperature. A, partial ¹³C{¹H} NMR spectrum (150 MHz) of an ∼equimolar mixture of [1-¹³C]erythritol and [1-¹³C]threitol showing signals arising only from the labeled carbons. B and C, the mixture in A was injected into the hemolymph of a deacclimated U. ceramboides and held either for 6 days at 0 °C (B) or 5 days at 4 °C (C). The homogenates of two insects are pooled for each sample. Signal assignments are as follows: C-1 threitol (a), C-1 erythritol (b), and ethylene glycol (c).