Phenolic Compounds From the Stems and Leaves of Berchemia lineata (L.) DC

Chemical Constituents from Berchemia polyphylla var. Leioclada

One previously undescribed naphthoquinone-benzisochromanquinone dimer berpolydiquinone A (1), along with two previously undescribed naphthoquinone-anthraquinone dimers berpolydiquinones B and C (2-3), and one previously undescribed dimeric naphthalene berpolydinaphthalene A (4), were isolated from the stems and leaves of Berchemia polyphylla var. leioclada. The chemical structures of these compounds were determined using high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), spectroscopic data, the exciton chirality method (ECM), and quantum chemical calculation. Notably, compounds (1-2 and 5) are dimeric quinones that share the same naphthoquinone moiety, specifically identified as 2-methoxystypandron. Compound (4) is a derivative of dimeric naphthalene with a symmetrical structure, which is a new structure type isolated from B. polyphylla var. leioclada for the first time. These findings suggest that B. polyphylla var. leioclada serves as a significant reservoir of structurally diverse phenolic compounds. This study provides a scientific foundation for regarding B. polyphylla var. leioclada as a potential source of "Tiebaojin".

Composition of Polygonatum zanlanscianense Pamp. Steam and Leaf Phenolic Extract and Its Protective Mechanism on t-BHP-Induced Oxidative Damage of HepG2 Cells

Plant phenolic compounds have attracted considerable attention because of their health benefits. This study aimed to investigate the composition and antioxidant activity of phenol extracts from Polygonatum zanlanscianense Pamp. steam and leaf (PPP). The FTIR, UPLC-Q-Obtrip-MS, and HPLC-DAD methods were used to analyze the composition of PPP, and 20 phenolic compounds were preliminarily identified. Among them, the contents of hyperin, astragalin, and diosmetin levels were the highest. Treatment with PPP can significantly reduce t-BHP-induced cell damage in HepG2 cells, reactive oxygen species (ROS) accumulation, and malondialdehyde (MDA) content. Meanwhile, the superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px) activities can be increased. Moreover, PPP enhanced Nrf2 expression, which was consistent with that of heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and NAD(P)H quinone oxidoreductase-1 (NQO1), whereas the expression of Keap1, the Nrf2 inhibitor, was decreased. All findings indicate that PPP can serve as a natural bioactive substance for preventing oxidative stress.