Extractives of Cercidiphyllum japonicum twigs: isolation and structural elucidation of a new galloylflavonol glycoside, anomeric tannins and flavonoids

Abstract

Cercidiphyllum japonicumis a deciduous tree that grows in East Asia, where its raw extracts have long been used in folk medicnes to treat various disorders or diseases. In the current work, extracts fromC. japonicumtwigs were studied for the first time. Seven individual compounds were isolated from the extracts, including a new galloylflavonol glycoside, namely 8-methoxykaempferol-4′-O-galloyl-3-O-α-L-rhamnopyranoside (VII), and six known phenolics [two anomeric galloyltannins (3,4,6-tri-O-galloyl-β-D-glucopyranoside (I) and 2,2′,5-tri-O-galloyl-α/β-D-hamamelose (III)), one anomeric ellagictannin, pedunculagin (II), one flavonol, kaempferol (V) and two flavonol derivatives (kaempferol-3-O-α-L-rhamnopyranoside (IV) and 8-methoxykaempferol (VI))]. Structural elucidation ofI–VIIwas conducted mainly on the basis of their spectroscopic [ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR), mass spectrometry (MS)] and physicochemical analysis, as well as by comparison of the analytical data with those in the literature. CompoundsI,II,IVandVIhave not yet been reported in the genusCercidiphyllum.CompoundVII, a previously undescribed flavonoid, was isolated and elucidated in this work for the first time.

Recovery and Seasonal Variation of Cinnamtannin B‐1 from Laurel (Laurus nobilis L.) Pruning Wood Wastes

“…Among all the plant‐based sources of bioactive compounds, agro‐industrial wastes are of special interest as a result of their low or null value as raw materials in addition to the socio‐environmental and sustainable aspects [4,5] . In fact, many examples of the valorization of agro‐industrial residues have been reported over the years, the topic being recently reviewed several times, [6–8] and used as residual biomasses for the isolation of both non‐chiral [9] and enantiomerically pure [10,11] phytochemicals.…”