To study alkaloid constituents in Corydalis decumbens,thirteen compounds were isolated from 95％ ethanol extracts of Corydalis decumbens (Thunb) Pers.by silica gel,RP-C1s,Sephadex LH-20 column chromatographer,recry stallization,thin-layer chromatography and HPLC.Their structures were elucidated on the basis of spectral data combined with physiochemical properties as tetrahydropalmatine (1),oxyhydrastinine (2),doryanine (3),palmatine (4),bicuculline (5),canadine (6),tetrahydrocoptisine(7),corydaldine (8),epicorynoxidine (9),N-methylcorydaldine (10),(+)-corlumine (11),N-methyl-6,7-dimethoxyisoquinolone (12) and oxysanguinarine (13).Compounds 2,3,6,7,and 9-13 were isolated from this plant for the first time.In addition,compounds 2,3,and 9-13 were obtained firstly from this genus.Pharmacological experiments showed that tetrahydropalmatine (1) might have analgesic or sedative effects,and the bicuculline (5) could probably induce epilepsy.

Stimulator of interferon genes (STING) is a cytosolic DNA sensor which is regarded as a potential target for antitumor immunotherapy. However, clinical trials of STING agonists display limited anti-tumor effects and dose-dependent side-effects like inflammatory damage and cell toxicity. Here, we showed that tetrahedral DNA nanostructures (TDNs) actively enter macrophages to promote STING activation and M1 polarization in a size-dependent manner, and synergized with Mn²⁺ to enhance the expressions of IFN-β and iNOS, as well as the co-stimulatory molecules for antigen presentation. Moreover, to reduce the cytotoxicity of Mn²⁺, we constructed a TDN-MnO₂ complex and found that it displayed a much higher efficacy than TDN plus Mn²⁺ to initiate macrophage activation and anti-tumor response both in vitro and in vivo. Together, our studies explored a novel immune activation effect of TDN in cancer therapy and its synergistic therapeutic outcomes with MnO₂. These findings provide new therapeutic opportunities for cancer therapy.