Effects of Quinizarin and Five Synthesized Derivatives on Fifth Larval Instar Midgut Ecdysone 20-Monooxygenase Activity of the Tobacco Hornworm Manduca sexta

Figure 2

(a) and (c), the structures of 2-hydroxy-1,4-anthraquinone (2OH) and 2-methoxy-1,4-anthraquinone (2MeO); (b) and (d), the effects of 2OH and 2MeO, expressed as percent of controls, on E20M activity of day 5 midgut homogenates of gate II fifth instar Manduca sexta. Each value including controls is the mean ±SEM of three determinations done in duplicate. Control E20M activity for 2OH was  pg 20E formed/min/mg tissue, while control E20M activity for 2MeO was  pg of 20E formed/min/mg tissue. Asterisks indicate significant differences compared to controls: *; ***.

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