Phenolic glycosides from Lindera fruticosa root and their inhibitory activity on osteoclast differentiation

Two new compounds were found in the phenolic glycosides isolated from the roots of Lindera fruticosa: 5-O-[beta-D-apiofuranosyl-(1'-->2')-O-beta-D-xylopyranosyl]gentisic acid-7,5'-ester (3), named linderofruticoside A; and 5-O-[beta-D-apiofuranosyl-(1'-->3')-O-beta-D-xylopyranosyl]gentisic acid methyl ester (4), linderofruticoside B. Two previously known phenolic glycosides were also identified: beta-D-(3,4-disinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (1) and beta-D-(3-sinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (2). Compounds 1 and 2 inhibited osteoclast differentiation in a dose-dependent manner at concentrations higher than 1.04 microM and 0.132 microM, respectively.     

Total synthesis of apios isoflavones and investigation of their tyrosinase inhibitory activity

Apios isoflavone glucosides 1 and 2 were synthesized for the first time via Friedel–Crafts reaction, Bischler–Napieralski-type cyclization, and phase-transfer catalyzed glycosylation as the key steps. In addition, aglycones 4 and 5 and related natural isoflavone cajanin (6) were synthesized in short steps. Evaluation of the inhibitory activity of these compounds toward tyrosinase indicated that all the compounds were active. In particular, the half-maximal inhibitory concentration of compound 1 toward tyrosinase was measured to be 729 μM.     

Constituents of the pollen of Crocus sativus L. and their tyrosinase inhibitory activity

Five new naturally occurring monoterpenoids, crocusatins-A (1), -B (2a), -C (3), -D (4a) -E (5), a new lactate, sodium (2S)-(O-hydroxyphenyl)lactate (6), and eighteen known compounds were isolated and characterized from the pollen of Crocus sativus L. The tyrosinase inhibitory activities of these compounds were also discussed.     

A new stilbene with tyrosinase inhibitory activity from Chlorophora excelsa

A new stilbene, 4-[(2"E)-7"-hydroxy-3",7"-dimethyloct-2"-enyl]-2',3,4',5-tetrahydroxy-trans-stilbene (1), and the known compound chlorophorin (2) were isolated from the heartwood of Chlorophora excelsa. Both 1 and 2 showed tyrosinase inhibitory activity with IC(50) values of 96 and 1.3 microM, respectively.     

Aromatic constituents from the heartwood of Santalum album L

A phytochemical investigation of the polar constituents in the heartwood of Indian Santalum album L. resulted in the isolation of three new neolignans (1-3) and a new aromatic ester (4), along with 14 known components. The structures of the new compounds (1-4) were established using spectroscopic methods.     

New constituents from the heartwood of Picea morrisonicola HAYATA

Three new constituents, including a p-menthane type monoterpene, trans-p-menthane-7,8,9-triol (1), an aromatic, 2,6-dihydroxy-3,4-dimethylbenzoic acid methyl ester (2), and a lignan, (+)-morrisonicolanin (3), were isolated from the low polar layer of heartwood extracts of Picea morrisonicola, and their structures were elucidated on the basis of spectroscopic analysis. Of these compounds identified, 1 was obtained as its diacetylated derivative 1a, and 2 was the chemical entity first isolated from a natural source.     

Phenolic constituents in Erythrina x bidwilli and their activity against oral microbial organisms.

Five flavonoid compounds, including two new isoflavanones, were isolated from the root bark of Erythrina x bidwilli. Their structures were determined to be 2,10-di(gamma,gamma-dimethylallyl)-3,9-dihydroxypterocarpan (erythrabyssin II), 6,8-di(gamma,gamma-dimethylallyl)-7,2',4'-trihydroxyisoflavanone (bidwillon A), 8-gamma,gamma-dimethylallyl-2',4'-dihydroxy-[6",6"-di-methylpyrano - (2",3":7,6)]isoflavanone (bidwillon B), 8-gamma,gamma-dimethylallyl-7,4'-dihydroxyisoflavone (8-gamma,gamma-dimethyl-allyldaidzein), and 8-gamma,gamma-dimethylallyl-5,2',4'-trihydroxy-[6",6"-dimethylpyrano+ ++- (2",3":7,6)]isoflavone (auriculatin), by means of spectroscopic analysis. Some potent activities against oral microbial organisms (Fusobacterium nucleatum and Prevotella intermedia) were shown in these flavonoid compounds.     

Phenolic constituents from Ephedra nebrodensis

Two new phenolic glycosides, 4-hydroxy-3-(3-methyl-2-butenyl)phenyl beta-D-glucopyranoside (nebrodenside A) and O-coumaric acid beta-D-allopyranoside (nebrodenside B), were isolated from the aerial parts of Ephedra nebrodensis. In addition, O-coumaric acid glucoside, (-)-epicatechin, and (-)-ephedrine were also isolated. The structures were deduced from extensive 1D and 2DNMR spectroscopy (1H, 13C, DQF-COSY, TOCSY, GHSQC, GHMQC, ROESY) as well as mass spectrometry (EI and HR-MALDI). (-)-Epicatechin showed weak antiviral activity against Influenza A virus and very weak cytotoxicity against MDCK cells.     

Phenolic constituents from Perovskia atriplicifolia

Perovskoate, an isorinic acid derivative (1) and perovskoside, the catechol derivative (2) have been isolated from the ethyl acetate soluble fraction of the whole plant of Perovskia atriplicifolia and assigned the structure 3(7-hydroxyphenyl)-2-hydroxy propanoic acid; (R)-form, 2-O-(6',7'-dihydroxy-E-cinnamoyl) (1) and 2-methoxy-4-(undecyl-4'-O-beta-D-glucopyranosyl) phenol (2). In addition, caffeic acid (3) and ferulic acid (4) have been reported for the first time from this species. The structures of these compounds were assigned on the basis of 1D and 2D NMR techniques. The compound 1 showed significant inhibitory activity against lipoxygenase and weak to moderate activity against cholinesterases.     

Chemical constituents from the bark of bauhinia purpurea and their NO inhibitory activities

Abstract

Phytochemical studies led to the isolation of a new phenylpropanoid glucoside, named purpuroside (1), along with eight known compounds (2–9) from the bark of Bauhinia purpurea. The structure of the new compound was elucidated on the basis of its spectroscopic data. The absolute configuration of compound 2 was verified by X-ray diffraction analysis. Compounds 1, 2, 7, 8, and 9 inhibited NO production in mouse peritoneal macrophages with IC₅₀ values from 35.5 to 63.0?μM.     

Isoflavanones from the heartwood of Swartzia polyphylla and their antibacterial activity against cariogenic bacteria.

The methanolic extract of Swartzia polyphylla DC. heartwood had antibacterial activity against cariogenic bacteria, the mutans Streptococci. The chromatographic purification of the extract afforded seven flavonoids. Among them, three known isoflavanones, dihydrobiochanin A, ferreirin and darbergioidin, and one new isoflavanone, 5,2',4'-trihydroxy-7-methoxyisoflavanone (dihydrocajanin) had potent antibacterial activity against cariogenic bacteria. This effect was not detected on isoflavone derivatives. A comparative antibacterial study of various flavonoids was further performed, and their structure-activity relationship was discussed.     

Volatile constituents of Amomum argyrophyllum Ridl. and Amomum dealbatum Roxb. and their antioxidant,tyrosinase inhibitory and cytotoxic activities

The volatile components from fresh rhizomes and leaves of Amomum argyrophyllum Ridl. and Amomum dealbatum Roxb. were performed using HS-SPME and charac-terized by GC–MS. A total of 49, 47, 49, and 34 compounds were identified from the rhizomes and leaves of A. argyrophyllum and A. dealbatum, respectively. The major components were β-pinene, α-pinene, and o-cymene. The rhizome extracts exhibited total phenolic content of 2.9 ± 0.5 and 2.1 ± 0.6 mg gallic acid equivalents. The IC₅₀ values of DPPH and ABTS were 179.8 ± 3.9 µg/mL, 392.9 ± 2.6 µg/mL, 120.3 ± 2.5 µg/mL, and 328.6 ± 3.3 µg/mL, respectively. The FRAP values were 76.5 ± 7.8 and 84.9 ± 4.4 µM ascorbic acid equivalents. The extracts showed weak antibacterial activity and tyrosinase inhibitory activity of 69.0 ± 3.6 and 53.7 ± 7.4 mg kojic acid equivalents. The cytotoxicity effect was assessed with the MTT assay at 200 µg/mL. The extracts showed no toxicity. In addition, the anti-inflammatory properties of extracts were evaluated, and showed potential to inhibit nuclear factor-κB (NF-κB) activity.     

Phenolic constituents from the roots of Alangium chinense

Three new phenolics(1–3) and twenty-eight known compounds(4–31) were isolated from an ethanolic extract of roots of Alangium chinense. Compound 11 exhibited antiviral activity against Coxsackie virus B3 with IC50 values of 16.89 mmol/L. Compounds 1, 10–17, 19–21, and 23 showed strong antioxidant activity against Fe~(2+)-cysteine-induced rat liver microsomal lipid peroxidation, with IC_(50) values of 0.14–8.18 mmol/L.     

Phenolic constituents from the rhizomes of Gastrodia elata

Gastrodia elata Bl. (Orchidaceae) is an important traditional medicinal plant as well as a famous foodstuff in China. In the present article, the HPLC chromatograms of different preparation processes were reported, and structures of nine phenolic compounds, isolated from Gastrodia elata, were assigned. The isolated compounds were identified as 1,3-bis(4-hydroxybenzyl)citrate (1), gastrodin (2), 4-hydroxybenzyl alcohol (3), 1-(4-beta-D-glucopyranosyloxybenzyl)citrate (4), 4-hydroxybenzaldehyde (5), parishin B (6), 4-hydroxybenzyl methyl ether (7), 4-hydroxybenzyl ethyl ether (8), and 4-(4'-hydroxybenzyl)phenol (9). Compounds 1 and 4, named as parishin D and E, were new. Their structures were elucidated on the basis of spectral analyses, including 2D NMR spectroscopy.     

Phenolic constituents from the rhizomes of Dryopteris crassirhizoma

A new phenolic glycoside, dryopteroside (1), was isolated from the rhizomes of Dryopteris crassirhizoma (Dryopteridaceae), together with five known compounds, 4beta-carboxymethyl-(-)-epicatechin (2), isobiflorin (3), biflorin (4), 1-beta-D-glucopyranosyloxy-3-methoxy-5-hydroxybenzene (5) and (+)-catechin-6-C-beta-D-glucopyranoside (6). The new compound was elucidated to be 1-butanoyl-3-C-beta-D-glucopyranosyl-5-methyl-phloroglucinyl-6-O-beta-D-glucopyranoside (1) by chemical and various spectroscopic analyses. The known compounds 2-6 were first reported from the genus Dryopteris.     

Water-soluble constituents of the heartwood of Streblus asper

A new lignan, (7'R,8'R)-threo-strebluslignanol-2-O-beta-D-glucopyranoside, along with 8 known compounds (2-9) were isolated from the water-soluble part of the MeOH extract of the heartwood of Streblus asper. Their structures were elucidated through various spectroscopic methods, including 1D NMR (1H NMR, 13C NMR), 2D NMR (HMQC, HMBC, and NOESY), and HRMS. The stereochemistry at the chiral centers was determined using the CD spectrum, as well as analyses of coupling constants and optical rotation data. In the preliminary bioassay, the isolated compounds did not show anti-HBV activities in vitro using the HBV transfected HepG2.2.15 cell line.     

Chemical constituents from Gueldenstaedtia verna and their anti-inflammatory activity

A new triterpenoid glycoside (1) and 15 known compounds (2–16) were isolated from the whole plants of Gueldenstaedtia verna. The new compound (1) was identified as complogenin 22-O-β-d-glucopyranoside by extensive spectroscopic techniques including 1D (¹H and ¹³C) and 2D NMR experiments (HSQC, HMBC and NOESY), HR-DART-MS and chemical methods. Most of the isolates were evaluated for their inhibitory activities on LPS-induced NO production in RAW 264.7 cells. The inhibitory effects of the active compounds, sulphuretin (8) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,9(11),22-trien-3β-ol (13), on the production of pro-inflammatory mediators (including IL-6, IL1β and PGE₂) were further estimated in vitro by ELISA in RAW 264.7 macrophages.     

Phenolic constituents from the fruit juice of Flacourtia inermis

A chemical investigation of the fruit juice of Flacourtia inermis furnished five caffeoylquinic acid derivatives: methyl chlorogenate (1), methyl 5-O-caffeoylquinate (2), methyl 4-O-caffeoylquinate (3), n-butyl chlorogenate (4), n-butyl 5-O-caffeoylquinate (5) and a rare phenolic glucoside (rel)-6α-benzoyloxy-1α,2α-dihydroxy-5-oxocyclohex-3-enecarboxylic acid 2-(6-O-benzoyl-β-D-glucopyranosyloxy)-5-hydroxybenzyl ester (6), together with quinic acid (7) and malic acid (8). Compounds 1, 2, 4 and 5 showed strong radical scavenging properties towards the 2,2'-diphenyl-1-picrylhydrazyl radical.     

Chemical constituents from Sambucus adnata and their protein-tyrosine phosphatase 1B inhibitory activities

The MeOH extract from the whole plants of Sambucus adnata has shown significant protein-tyrosine phosphatase 1B (PTP1B) inhibitory activity. Chemical study on the extract resulted in the isolation of thirteen compounds, including a novel triterpene (1). The structure of 1 was determined to be 1α,3β-dihydroxy-urs-12-en-11-one-3-yl palmitate on the basis of extensive spectroscopic analyses. Among the isolated compounds, ursolic acid, oleanolic acid and (±)-boehmenan showed the most potent PTP1B inhibitory activity in vitro with the IC(50) values of 4.1, 14.4 and 43.5 μm, respectively. The kinetic analysis indicated that (±)-boehmenan inhibits PTP1B activity in a competitive manner.     

Chemical constituents of Blumea balsamifera of Indonesia and their protein tyrosine phosphatase 1B inhibitory activity

A methanol extract of the leaves of Blumea balsamifera (L.) DC. (Asteraceae) afforded a new guaian-type sesquiterpene, epiblumeaene K (1), together with four known guaian-type sesquiterpenes (2-5), three known sesquiterpenes (6-8), and nine known flavonoids (9-17) by a combination of chromatography and preparative TLC techniques. Their structures were elucidated by extensive spectroscopic methods and comparison with the literature data. Among the isolated compounds, a known sesquiterpene, beta-caryophyllene 8R,9R-oxide (6), exhibited a significant PTP1B inhibitory activity in a dose-dependent manner, with an IC50 value of 25.8 microM (5.62 microg/mL).