Constituents from the Leaves of Phellodendron amurense and Their Antioxidant Activity

Abstract

There are about 10 species in the genus Phellodendron, distributed widely over the tropical and subtropical areas of Asia. The thick corky bark of Phellodendron amurense has a long history of ethnobotanical use among native peoples in East Asia. Diabetes mellitus, meningitis, pneumonia, antistomachic, intestinal function control, anti-inflammatory, anti-psychic, hest relief, bacillary dysentery, diarrhea, tuberculosis and liver cirrhosis treatments are among the indications listed for Huangbai, as the baric is commonly known. 1-3)Plants of the genus Phellodendron are known to be rich sources of berberine and aphorphine alkaloids, flavonoids, various coumarins, lignans and limonoids. [3][4][5][6][7][8][9] In our ongoing investigation of biologically active compounds form the titled plant, we have isolated three new coumarins and a new glutaric acid derivative along with twenty-nine known compounds from the CHCl 3 soluble portion of the MeOH extract of the leaves of the P. amurense. In this paper, we describe the isolation, structure elucidation of four new compounds and DPPH radical scavenging activity of the compounds. Results and DiscussionThe methanolic extract of the leaves of P. amurense was partitioned with CHCl 3 and H 2 O. The CHCl 3 soluble portion were purified by various column chromatographies and HPLC method using different solvent combinations to afford compounds 1-4 ( Fig. 1) and 29 known compounds. The known compounds were identified as amurensin (5), 6) phella-13) flavaprenin 7,4Ј-diglucoside (13), 14) hexandraside E (14), 15) umbelliferon (15) and 2-acetyl-5-methoxyfuran (33) 29) by comparison of their spectra with literature data.Phellodenol-F (1) was obtained as yellow syrup with elemental composition of C 14 H 16 O 7 determined from its HR-EI-MS ([M] ϩ m/z 296.0897). The UV absorption maxima at 225, 305 (sh), and 327 nm and the IR bands at 3400 and 1719 cm Ϫ1 consistent with the presence of hydroxyl and conjugated ester carbonyl groups. The 1 H-NMR spectrum revealed AB-type protons at d 7.90 and 6.17 (Jϭ9.4 Hz) signals indicative of the H-3 and H-4 protons of the coumarin nucleus. Two aromatic protons singlets at d 7.61 and 6.70 were assignable for H-5 and H-8, respectively. The up-field shift of H-8 suggested that a free hydroxyl group substituted at C-7. This was supported by the bathochromic shift of 47 nm observed in the UV absorption maxima after addition of NaOAc.7) The 1 H-NMR spectrum also revealed signals for two oxygenated methine signals (d 5.44, 1H, br, 4.40, 1H, d, Jϭ4.4 Hz) and two methyl groups (d 1.28 and 1.27, each 3H, s). The 13 C-NMR spectrum also revealed corresponding signals at d 99.0, 71.5, 70.3, 25.2 and 25.1. Since molecular formula contained 7 oxygen atoms and the above spectral analysis accounted for 6 oxygen atoms, the presence of peroxy group was inferred. The downfield chemical shifts of oxygenated methine proton H-2Ј and the corresponding carbon at d 4.40 and 99.0 suggested a hydroperoxide group at C-2Ј. The location of peroxyl group at C-2Ј was also indirec...

HPLC/QTOF‐MS/MS application to investigate phenolic constituents from Ficus pandurata H. aerial roots

“…S5A). The [ 23 − H] − ( m/z 367.1032, C 17 H 19 O 9 − ), producing a fragment ion at m/z 205.0512 (C 11 H 9 O 4 − ) by the loss of a glucoside, was deduced to be phellodenol‐H (Leu et al ., ; Fig. S5B).…”

Amur velvet: botanical and geographical characteristics, chemical composition, experience and prospects of application in medicine and pharmacy

“…Фенольные соединения бархата амурского представлены разными классами БАВ. В листьях бархата амурского идентифицированы производные гидроксибензойных кислоты (п-гидроксибензойная кислота и её метиловый эфир, метиловый эфир п-анисовой кислоты) и соответствующие им альдегиды: пгидроксибензальдегид, анисовый альдегид [1,15].…”

“…Листья бархата амурского накапливают такие соединения из группы кумаринов, как умбеллиферон, эскулетин, скополетин, ксантилетин, деметилсуберозин, скиммин, скопарон, феллоденолы А, F, G, H [1,15].…”

“…В листьях идентифицированы флаван эводиозид B, флаванонолы фелламурин, флакозид (феллавин), феллодендрозид, фелламуретин, дигидрофеллозид, флавон диосмин, флавонолы кемпферол, кверцетин и их 3-O-глюкозиды и 3-О-галактозиды, амуренсин, гександрозид Е, феллозид, феллатин, норикаризид [1,16].…”

Advancing HPLC-PDA-HRMS-SPE-NMR Analysis of Coumarins in Coleonema album by Use of Orthogonal Reversed-Phase C18 and Pentafluorophenyl Separations

“…Fifteen repetitive separations of 10 μL each of a 12.5 mg/mL solution allowed cumulative trapping of 18 peaks (Figure S1, Supporting Information). Using the peak and compound numbering scheme (in italics and bold, respectively) as for the subsequent HPLC-PDA-HRMS-SPE-cryoNMR analysis of preparative-scale fractions (Figure 1), the compounds eluted with eight of the trapped peaks were identified as (Z)-6-(4-hydroxy-3-methylbut-2-en-1-yl)coumarin 7-O-β-D-glucopyranoside (5), 19 7-(2,3-dihydroxy-3-methylbutyloxy)coumarin ( 9), 4 8-(2,3-dihydroxy-3-methylbutyloxy)-7-methoxycoumarin (12), 20 8-(2-hydroxy-3-methylbut-3-en-1-yloxy)-7-methoxycoumarin ( 16), 20 6-(2-hydroxy-3-methylbut-3-en-1-yl)-7-methoxycoumarin (17), 21 6-(2,3-dihydroxy-3-methylbutyl)-7methoxycoumarin (18), 5 (E)-3,7-dimethylocta-2,6-dien-1-yl 2-((3-methylbut-2-en-1-yl)amino)benzoate (25), 22 and (2E,4E)-N-isobutyldeca-2,4-dienamide (26) 23 with the remaining eight peaks in the pilot project could not be established unambiguously. However, as the obtained NMR and MS data suggested the presence of additional glycosylated and chlorinated coumarins, it was decided to perform preparative-scale HPLC separation using a C 18 column, followed by HPLC-PDA-HRMS-SPE-cryoNMR analysis of all fractions using an analytical-scale pentafluorophenyl (PFP) column.…”