Antioxidative iridoid glycosides from the sky flower (Duranta repens Linn).

Phytochemical investigations were performed on the EtOAc-soluble fraction of the whole plant of the sky flower (Duranta repens) which led to the isolation of the iridoid glycosides 1-6. Their structures were elucidated by both 1D and 2D NMR spectroscopic analysis. All the compounds showed potent antioxidative scavenging activity in four different tests, with half maximal inhibitory concentration (IC(50)) values in the range 0.

Xanthine oxidase/tyrosinase inhibiting, antioxidant, and antifungal oxindole alkaloids from Isatis costata.

Phytochemical investigations on the ethyl acetate soluble fraction of the whole plant of Isatis costata Linn. (Brassicaseae) led to the isolation of the oxindole alkaloids costinones A (1), B (2), isatinones A (3), B (4), indirubin (5), and trisindoline (6). Compounds 1-6 displayed significant to moderate inhibition against xanthine oxidase enzyme with IC50 values ranging from 90.

Two new anti-plasmodial flavonoid glycosides from Duranta repens.

The CHCl(3)-soluble fraction of the whole plant of Duranta repens showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum, with IC(50) values of 8.5 ± 0.9 and 10.