To
discover natural-product-based pesticides, 7β-oxycarbonylandrographolide
derivatives were stereoselectively constructed from a labdane diterpenoid
andrographolide. Among them, 2′-(n)Pr-1′,3′-dioxin-7β-oxy(m-Cl)benzoylandrographolide (IIc), 2′-(n)Pr-1′,3′-dioxin-7β-oxyacetylandrographolide
(IIf), 2′-(p-Me)Ph-1′,3′-dioxin-7β-oxy(o-Cl)benzoylandrographolide (Vb), and 2′-(p-Me)Ph-1′,3′-dioxin-7β-oxy(m-Cl)benzoylandrographolide (Vc) against Mythimna separata displayed the most promising growth
inhibitory activity; 2′-(n)Pr-1′,3′-dioxin-7β-oxy(o-Cl)benzoylandrographolide (IIb: LC50 = 0.406 mg/mL) and IIc (LC50 = 0.415 mg/mL)
exhibited the most pronounced acaricidal activity (andrographolide;
LC50: 5.106 mg/mL) and good control effects against Tetranychus cinnabarinus; compounds Ic, IIe, and Va–c (LD50 = 0.035–0.039 μg/nymph) showed potent aphicidal
activity (andrographolide: LD50 = 0.178 μg/nymph),
and compounds IIe and Vb showed good control
effects against Aphis citricola. Moreover,
it was found that Hsp70 of A. citricola was an important gene involved in stress response to andrographolide
and its derivatives.