Chaenomelin, a New Phenolic Glycoside, and Anti- Phenolic Compounds from the Leaves of .

Kimura, commonly known as pussy willow, is a deciduous shrub and tree belonging to the Salicaceae family. The genus spp. has been known as a healing herb for the treatment of fever, inflammation, and pain relief. The current study aimed to investigate the potential bioactive natural products from leaves and evaluate their antibacterial activity against . A phytochemical investigation of the ethanol (EtOH) extract of leaves led to the isolation of 13 phenolic compounds (-) from the ethyl acetate (EtOAc) fraction, which showed antibacterial activity against strain 51. The chemical structure of a new phenolic glycoside, chaenomelin (), was established by a detailed analysis of 1D and 2D (H-H correlation spectroscopy (COSY), heteronuclear single-quantum coherence (HSQC), and heteronuclear multiple-bond correlation (HMBC)) nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectroscopy (HR-ESIMS), and chemical reactions. The other known compounds were identified as 5--coumaroyl quinic acid methyl ester (), tremulacin (), citrusin C (), benzyl 3---d-glucopyranosyl-7-hydroxybenzoate (), tremuloidin (), 1-[--d-glucopyranosyl(1→2)--d-glucopyranosyl]oxy-2-phenol (), arbutin cinnamate (), tremulacinol (), catechol (), 4-hydroxybenzaldehyde (), kaempferol 3-rutinoside (), and narcissin (), based on the comparison of their NMR spectra with the reported data and liquid chromatography/mass spectrometry (LC/MS) analysis. The isolated compounds were evaluated for antibacterial activity against strain 51. Among the isolates, 1-[--d-glucopyranosyl(1→2)--d-glucopyranosyl]oxy-2-phenol () and arbutin cinnamate () exhibited antibacterial activity against strain 51, with inhibitions of 31.4% and 33.9%, respectively, at a final concentration of 100 μM. These results were comparable to that of quercetin (38.4% inhibition), which served as a positive control. Generally, these findings highlight the potential of the active compounds and as antibacterial agents against .