Unveiling the potential of medicinal herbs as the source for screening toward the inhibition of Nrf2.

Background: Drug resistance is one of the leading causes attributed to the failure of cancer treatment by chemotherapy. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating gene expression in cell defense against oxidative stress or hazardous factors. Taking advantage of this feature, Nrf2 also serves as the bodyguard for both normal and cancer cells.

Two new meroterpenoids from the aerial parts of (Vitaceae).

From EtOAc-soluble fraction of the aerial parts of (Vitaceae), two new meroterpenoids named ampechromonol A () and ampechromonol B (), together with five known compounds (-), were isolated. Their structures were elucidated based on NMR spectroscopic analysis. The plausible biosynthesis pathway for the formation of two new meroterpenoids was proposed.

A new cardenolide glycoside from the roots of (lour.) merr. (Asclepiadaceae).

From remaining aqueous fraction of the roots of , one new cardiac glycoside named periplogenin 3---gentiobioside () together with six known ones () were isolated. Their relative structures were elucidated based on NMR spectroscopic analysis. Compound showed moderate cytotoxicity against non-small cell lung carcinoma NCI-H460 and ovarian cancer HeLa cells.

Nimbandiolactone-21 and nimbandioloxyfuran, two new 28-norlimonoids from the leaves of (Meliaceae).

From an EtOAc-soluble fraction of the leaves of , two new 28-norlimonoids named nimbandiolactone-21 () and nimbandioloxyfuran (), together with nimbandiolactone-23 (), were isolated. Their relative structures were elucidated based on NMR spectroscopic interpretation and biosynthetic consideration. Nimbandioloxyfuran () and nimbandiolactone-23 () showed potent -glucosidase inhibitory activity, with the IC values of 46.

Cleistanthane diterpenes from the seed of Caesalpinia sappan and their antiausterity activity against PANC-1 human pancreatic cancer cell line.

Three new cleistanthane diterpenes named tomocinon (1), tomocinol A (2), and tomocinol B (3), were isolated from the EtOAc extract of the seed of Caesalpinia sappan. Their structures were determined by extensive NMR spectroscopic analysis. The absolute stereochemistry of tomocinon (1) has been established by CD spectroscopic analysis.