This study focused on exploring the nuclear factor-erythroid-2-related factor (Nrf2) active compound to avoid oxidative stress related to various diseases, such as obesity and diabetes mellitus. The activity of the Nrf2-ARE (antioxidant response element) signaling was evaluated by a reporter assay involving over five hundred various edible medicinal herbs, and the highest Nrf2 activity was found in the ethanol extract of Peucedanum japonicum leaves. The active compound in the extract was isolated by high performance liquid chromatography (HPLC), and the chemical structure was identical to pteryxin based on ¹H, ¹³C-NMR spectra and liquid chromatography/time-of-fright mass spectrometer (LC/TOF/MS). From the pteryxin, the transcription factor Nrf2 was accumulated in the nucleus and resulted in the expression of the antioxidant protein, heme oxygenase-1 (HO-1). In addition, the Nrf2 activity involving HO-1 expression due to coumarin derivatives was evaluated together with pteryxin. This suggested that the electrophilicity, due to the α,β-carbonyl and/or substituted acyl groups in the molecule, modulates the cysteine residue in Keap1 via the Michel reaction, at which point the Nrf2 is dissociated from the Keap1. These results suggest that pteryxin will be a useful agent for developing functional foods.

A series of new C₁₁ cyclopentenones 1-7 was isolated, together with four known metabolites 9/1 0, 1 2 and 1 3, from the extract of the didemnid ascidian Lissoclinum sp. The other didemnid ascidian Diplosoma sp. contained didemnenones 1, 2 and 5, and five known metabolites 8-1 2. The structures of 1-7 were elucidated by spectroscopic analyses. Cytotoxicity of the isolated compounds was evaluated against three human cancer cell lines (HCT116, A431 and A549).

Gymnema inodorum (GI) is an indigenous medicinal plant and functional food in Thailand that has recently helped to reduce plasma glucose levels in healthy humans. It is renowned for the medicinal properties of gymnemic acid and its ability to suppress glucose absorption. However, the effects of gymnemic acids on adipogenesis that contribute to the accumulation of adipose tissues associated with obesity remain unknown. The present study aimed to determine the effects of gymnemic acids derived from GI tea on adipogenesis. We purified and identified GiA-7 and stephanosides C and B from GI tea that inhibited adipocyte differentiation in 3T3-L1 cells. These compounds also suppressed the expression of peroxisome proliferator-activated receptor gamma (Pparγ)-dependent genes, indicating that they inhibit lipid accumulation and the early stage of 3T3-L1 preadipocyte differentiation. Only GiA-7 induced the expression of uncoupling protein 1 (Ucp1) and pparγ coactivator 1 alpha (Pgc1α), suggesting that GiA-7 induces mitochondrial activity and beige-like adipocytes. This is the first finding of stephanosides C and B in Gymnema inodorum. Our results suggested that GiA-7 and stephanosides C and B from GI tea could help to prevent obesity.

The unstable isomeric compounds 5-hydroxy-7-prop-2-en-(E)-ylidene-7,7adihydro-2H-cyclopenta[b]pyran-6-one (1) and 5-hydroxy-7-prop-2-en-(Z)-ylidene-7,7adihydro-2H-cyclopenta[b]pyran-6-one (2), previously described as antimicrobialmetabolites from the sponge Ulosa sp., were isolated and identified as major componentsof the ascidian Diplosoma virens. In this paper, full spectral data for 2 and complete ¹³CNMRdata for 1, based on 2D NMR measurements, are provided for the first time.Compounds 1 and 2 showed cytotoxity against HCT116 cells (human colorectal cancercells) by triggering apoptotic cell death.

Pentylphenols 1 and 2, cyclopropane fatty acid 3, and cyclopentenones 4 and 5, were isolated from an ascidian, Diplosoma sp. The structures of 1-5 were determined by spectroscopic analysis and/or synthesis. Compound 1 inhibited the division of fertilized sea urchin eggs and compound 4 showed mild cytotoxity against HCT116 cells (human colorectal cancer cell).