Flavonoids and Terpenoids with PTP-1B Inhibitory Properties from the Infusion of Ortega.

An infusion prepared from the aerial parts of Ortega inhibited the enzyme protein tyrosine phosphatase 1B (PTP-1B) (IC~88 and 33 μg/mL, respectively). Phytochemical analysis of the infusion yielded amarisolide (), 5,6,4'-trihydroxy-7,3'-dimethoxyflavone (), 6-hydroxyluteolin (), rutin (), rosmarinic acid (), isoquercitrin (), pedalitin () and a new -clerodane type diterpenoid glucoside, named amarisolide G (,). Compound , is a new natural product, and - are reported for the first time for the species. All compounds were tested for their inhibitory activity against PTP-1B; their IC values ranged from 62.0 to 514.2 μM. The activity was compared to that of ursolic acid (IC = 29.14 μM). The most active compound was pedalitin (). Docking analysis predicted that compound has higher affinity for the allosteric site of the enzyme. Gas chromatography coupled to mass spectrometry analyses of the essential oils prepared from dried and fresh materials revealed that germacrene D () and β-selinene (), followed by β-caryophyllene () and spathulenol () were their major components. An ultra-high performance liquid chromatography coupled to mass spectrometry method was developed and validated to quantify amarisolide () in the ethyl acetate soluble fraction of the infusion of .