Polyphenols from the Root Barks of Ulmus davidiana var. japonica and Their Wound Healing Potential

The root bark of Ulmus davidiana var. japonica (Ulmaceae), commonly known as yugeunpi, has long been used in traditional Korean medicine to treat gastroenteric and inflammatory disorders, as well as to promote blood circulation and tissue regeneration. As part of our ongoing efforts to discover bioactive natural products from resources with pharmacological potential, a phytochemical investigation of the root bark of U. davidiana var. japonica was conducted, and the wound-healing potential of the isolated compounds was evaluated. This study led to the isolation of one new catechin glycoside derivative, (–)-catechinulmusol (1) and two new neolignan derivatives, neolignulmusides A and B (2 and 3), along with ten known compounds (4–13), including lignans (4 and 5), flavonoids (6–10), and phenolic derivatives (11–13). The structures of the new compounds (1–3) were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and chemical derivatization. Results from in vitro assays revealed that compounds 1, 4, 6, and 13 significantly promoted the migration of human skin keratinocytes. These findings suggest that these active compounds may serve as promising candidates for skin wound-healing applications, including epidermal regeneration.