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

Figure 1

(a) and (c), the structures of quinizarin (QZ) and 1,4-anthraquinone (AQ); (b) and (d), the effects QZ and AQ, 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 QZ was  pg 20E formed/min/mg tissue, while control E20M activity for AQ was  pg 20E formed/min/mg tissue. Asterisks indicate significant differences compared to controls: *; **; ***.

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