Acylated iridoid diglycosides from the cultivated endangered ornamental tree Gmelina hainanensis

•The cultivated endangered plant Gmelina hainanensis was phytochemically investigated.•Two new and 10 known acylated iridoid diglycosides were isolated and characterized.•Their structures were defined by spectroscopic methods and chemical transformation.•The isolates were evaluated for their PTP1B and neuroinflammation inhibitory effects.