Flavans from the leaf of Ilex centrochinensis

Phytochemical investigation of the leaf of Ilex centrochinensis led to the isolation and characterization of four flavans, one flavanone (5), and one flavone (6), including a new compound whose structure was elucidated as (2S)-5,3′,4′-trihydroxy-7-methoxyflavan (1) and a new natural product whose structure was elucidated as (2S)-5-hydroxy-7,3′,4′-trimethoxyflavan (4) on the basis of spectroscopic methods especially 1D and 2D NMR, CD, and mass spectral analyses. Compounds 1 and 4 exhibited weak cytotoxic activity against Huh7 cell line and no cytotoxic activity against Caco-2 cell line.     

Anti-inflammatory coumarins from Paramignya trimera

Context: Paramignya trimera (Oliv.) Burkill (Rutaceae) has been used to treat liver diseases and cancer. However, the anti-inflammatory effects of this medicinal plant and its components have not been elucidated.

Objective: This study investigated chemical constituents of the P. trimera stems and evaluated anti-inflammatory effects of isolated compounds.

Materials and methods: Cytotoxicity of isolated compounds (5–40?μM) toward BV2 cells was tested using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) for 24?h. Inhibitory effects of isolated compounds (5-40?μM) on nitrite and PGE₂ concentrations were determined using Griess reaction and PGE₂ ELISA kit, respectively (pretreated with the compounds for 3?h and then stimulated for 18?h with LPS). Inhibitory effects of compounds (5-40?μM) on iNOS and COX-2 protein expression were evaluated by Western blot analysis (pretreated with the compounds for 3?h and then stimulated for 24?h with LPS).

Results: Seven coumarins were isolated and identified as: ostruthin (1), ninhvanin (2), 8-geranyl-7-hydroxycoumarin (3), 6-(6′,7′-dihydroxy-3′,7′-dimethylocta-2′-enyl)-7-hydroxycoumarin (4), 6-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-7-hydroxycoumarin (5), 6-(2-hydroxyethyl)-2,2-dimethyl-2H-1-benzopyran (6), and luvangetin (7). Compounds 1–4 and 7 inhibited NO and PGE₂ production in LPS-stimulated BV2 cells, with IC₅₀ values ranging from 9.8 to 46.8 and from 9.4 to 52.8?μM, respectively. Ostruthin (1) and ninhvanin (2) were shown to suppress LPS-induced iNOS and COX-2 protein expression.

Discussion and conclusion: The present study provides a scientific rationale for the use of P. trimera in the prevention and treatment of neuroinflammatory diseases. Ostruthin and ninhvanin might have potential therapeutic effects and should be considered for further development as new anti-neuroinflammatory agents.     

Two novel flavanes from the leaves of Morus alba L.

Two new flavanes, (2R,4S)-2′,4′-dihydroxy-2H-furan-(3″,4″:8,7)-flavan-4-ol (1) and (2S)-2′,4′-dihydroxy-7-methoxyl-8-butyricflavane (2), together with four known flavonoids, were isolated from the leaves of Morus alba L. Their structures were determined on the basis of spectroscopic analysis.     

Structural elucidation of a new flavone from Sarcopyramis nepalensis

A novel flavone, named 4′-methoxy-3′,5,7-trihydroxy-8-(1″-(3?,4?,5?-trihydroxyphenyl)ethyl)flavone (1), was isolated from Sarcopyramis nepalensis, along with two known compounds syringaresinol (2) and aralidioside (3). Their structures were established by the spectroscopic analysis, especially by 2D NMR. All of the three compounds were isolated from the plant for the first time.     

Two new flavonoids from the roots of Scutellaria baicalensis

One new flavone, 5,7-dihydroxy-8,2′,3′,6′-tetramethoxyflavone (1), and one new flavonol, 5,7,6′-trihydroxy-2′-methoxyflavonol (2), were isolated from the roots of Scutellaria baicalensis, and their structures were elucidated on the basis of extensive spectroscopic evidences, especially 1D and 2D NMR and HR-ESI-MS experiments. The structure features of these new compounds lie in the substitution at both C-2′ and C-6′ positions of B-ring by hydroxyl or methoxyl groups.     

New flavonoids and other constituents from Lespedeza cuneata

Two new flavonoids, 6,8,3′,4′-tetrahydroxy-2′-methoxy-7-methylisoflavanone (1) and 6,8,3′,4′-tetrahydroxy-2′-methoxy-6′-(1,1-dimethylallyl)-isoflavone (2), were isolated from the 95% ethanolic extract of the dried roots of Lespedeza cuneata together with betulinic acid (3), β-sitosterol (4), hexacosanoic acid 2,3-dihydroxy-propyl ester (5), which were isolated from this plant for the first time. Their structures were elucidated by spectral analysis.     

Cytotoxic C-Methylated Chalcones from Syzygium samarangense.

Abstract

The flavonoids 2′-hydroxy-4′,6′-dimethoxy-3′-methylchalcone (1), 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (2), 2′,4′-dihydroxy-6′-methoxy-3′-methylchalcone (3), 2′,4′-dihydroxy-6′-methoxy-3′-methyldihydrochalcone (4) and 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethyldihydrochalcone (5), isolated from Syzygium samarangense. (Blume) Merr. & L.M. Perry (Myrtaceae), were subjected to cytotoxicity testing using the dimethylthiazoldiphenyl tetrazolium (MTT) assay. The cell lines used were the Chinese hamster ovarian (CHO-AA8) and the human mammary adenocarcinoma, (MCF-7 and SKBR-3). Among the test compounds, 2 exhibited significant differential cytotoxicity against the MCF-7 cell line with an IC₅₀ of 0.0015 ± 0.0001 nM. It was also cytotoxic against the SKBR-3 cell line with an IC₅₀ of 0.0128 ± 0.0006 nM. Doxorubicin, the positive control, had an IC₅₀ of 2.60 ± 0.28 × 10^?4 nM against the MCF-7 cell line and an IC₅₀ of 2.76 ± 0.52 × 10^?5 nM against the SKBR-3 cell line. When tested in a mechanism-based yeast bioassay for detecting DNA-damaging agents using genetically engineered Saccharomyces cerevisiae. RS322Y (RAD52) mutant strain and (LF15/11) (RAD+) wild-type strain, 2 showed significant selective cytotoxicity against the RAD52 yeast mutant strain. It had an IC₁₂ of 0.1482 nM, as compared with the positive control, streptonigrin, which had an IC₁₂ of 0.0134 nM. Hence, 2 is a cytotoxic natural product with potential anticancer application.     

Two new 5,8-quinoflavans from the leaf of Ilex centrochinensis

Two new 5,8-quinoflavans were isolated from the leaf of Ilex centrochinensis, and their structures were elucidated as (2R)-7,3′,4′-trimethoxy-5,8-quinoflavan and (2S)-7-methoxy-4′-hydroxy-5,8-quinoflavan on the basis of spectroscopic methods, especially 1D and 2D NMR, CD, and mass spectral analyses. Both of them exhibited weak cytotoxic activity against HuH7 cell lines and no cytotoxic activity against CaCO-2 cell lines.     

Three new compounds from Arnebia euchroma

A new naphthoquinone dimer, arnebiabinone (1), a new phenolic compound, ethyl 9-(2′,5′-dihydroxyphenyl) nonanoate (2), and a new natural product, octyl ferulate (3), were isolated from the EtOH extract of dried roots of Arnebia euchroma (Royle) Johnst. Their structures were elucidated on the basis of chemical reaction and spectral analysis.     

Two new phenol derivatives from Stereum hirsutum FP-91666

Two new phenol derivatives, 2-(3-methyl-2-buten-1-yl)-4-methoxyethyl-phenol (1) and 5-hydroxy-4-(hydroxymethyl)-2-(3-methylbut-2-en-1-yl)cyclohex-4-en-1-one (2), together with eight known compounds consisting of phenol derivatives (3 and 4), niacinamide (5), and five ergosta type compounds (6–10), were isolated from solid fermentation products of Stereum hirsutum FP-91666. Two new structures were elucidated by extensive spectroscopic methods, including 1D NMR and 2D NMR, and HR-EI-MS experiments.     

A new para-quinone-type flavan from the leaves of Ilex centrochinensis and its anti-inflammatory activities

A new para-quinone-type flavan, (2S)-7-methoxy-3′,4′-dihydroxy-5,8-quinoflavan (1), together with three known compounds, were isolated from the leaves of Ilex centrochinensis. Their structures were elucidated by detailed spectroscopic analyses for new structure and in comparison with published data for known compounds. Moreover, the new compound was evaluated its cytotoxic and anti-inflammatory activities in vitro on LPS induced RAW 264.7 cells and the results showed that 1 has promising anti-inflammatory activities.     

Anti-HIV-1 integrase compounds from Dioscorea bulbifera and molecular docking study

Context Dioscorea bulbifera L. (Dioscoreaceae) has been used in a traditional Thai longevity medicine preparation. Isolation of inhibitors from natural products is a potential source for continuous development of new HIV-1 integrase (IN) inhibitors.

Objective The objective of this study is to isolate the compounds and evaluate their anti-HIV-1 IN activity, as well as to predict the potential interactions of the compounds with an IN.

Materials and methods The ethyl acetate and water fractions (1–100?μg/mL) of Dioscorea bulbifera bulbils were isolated and tested for their anti-HIV-1 IN activity using the multiplate integration assay (MIA). The interactions of the active compounds with IN were investigated using a molecular docking method.

Results and discussions The ethyl acetate and water fractions of Dioscorea bulbifera bulbils afforded seven compounds. Among these, allantoin (1), 2,4,3′,5′-tetrahydroxybibenzyl (2), and 5,7,4′-trihydroxy-2-styrylchromone (5) were isolated for the first time from this plant. Myricetin (4) exhibited the most potent activity with an IC₅₀ value of 3.15?μM, followed by 2,4,6,7-tetrahydroxy-9,10-dihydrophenanthrene (3, IC₅₀ value=?14.20?μM), quercetin-3-O-β-d-glucopyranoside (6, IC₅₀ value?=?19.39?μM) and quercetin-3-O-β-d-galactopyranoside (7, IC₅₀ value?=?21.80?μM). Potential interactions of the active compounds (3, 4, 6, and 7) with the IN active site were additionally investigated. Compound 4 showed the best binding affinity to IN and formed strong interactions with various amino acid residues. These compounds interacted with Asp64, Thr66, His67, Glu92, Asp116, Gln148, Glu152, Asn155, and Lys159, which are involved in both the 3′-processing and strand transfer reactions of IN. In particular, galloyl, catechol, and sugar moieties were successful inhibitors for HIV-1 IN.     

Three new amides from Microlepia pilosissima

Phytochemical investigation of 70% EtOH extract of the dry fronds of Microlepia pilosissima has resulted in isolation of three new amides, (7E)-N-(3′-hydroxyl-4′-methoxy)-phenylethyl-4-hydroxyl-cinnamamide (1), (7E)-N-(3′,4′,5′-trihydroxyl)-phenylethyl-4-hydroxyl-cinnamamide (2), and (7E)-N-(3′,4′,5′-trihydroxyl)-phenylethyl-4-methoxy-cinnamamide (3). Their structures were characterized by spectroscopic analysis and chemical method, including 1D NMR, 2D NMR, and HR-ESI-MS.     

Identification of cytochrome P450 enzymes involved in the metabolism of 3′,4′-methylenedioxy-α-pyrrolidinopropiophenone (MDPPP), a designer drug,in human liver microsomes

The metabolism of 3′,4′-methylenedioxy-α-pyrrolidinopropiophenone (MDPPP), a novel designer drug, to its demethylenated major metabolite 3′,4′-dihydroxy-pyrrolidinopropiophenone (di-HO-PPP) was studied in pooled human liver microsomes (HLM) and in cDNA-expressed human hepatic cytochrome P450 (CYP) enzymes. CYP2C19 catalysed the demethylenation with apparent K_m and V_max values of 120.0?±?13.4?µM and 3.2?±?0.1?pmol/min/pmol?CYP, respectively (mean?±?standard deviation). CYP2D6 catalysed the demethylenation with apparent K_m and V_max values of 13.5?±?1.5?µM and 1.3?±?0.1 pmol/min/pmol?CYP, respectively. HLM exhibited a clear biphasic profile with an apparent K_m,1 value of 7.6?±?9.0 and a V_max,1 value of 11.1?±?3.6?pmol/min/mg?protein, respectively. Percentages of intrinsic clearances of MDPPP by specific CYPs were calculated using the relative activity factor (RAF) approach with (S)-mephenytoin-4′-hydroxylation or bufuralol-1′-hydroxylation as index reactions for CYP2C19 or CYP2D6, respectively. MDPPP, di-HO-PPP and the standard 4′-methyl-pyrrolidinohexanophenone (MPHP) were separated and analysed by liquid chromatography-mass spectrometry in the selected-ion monitoring (SIM) mode. The CYP2D6-specific chemical inhibitor quinidine (3?µM) significantly (p?相似文献   

Two new phenolic compounds from the tuber of Sparganium stoloniferum

Two new phenolic compounds, 2-(2-hydroxyphenyl)-4-methoxycarbonyl-5-hydroxybenzofuran (1) and 1-methoxycarbonyl-2, 3-dihydroxydibenzo[b, f]oxepine (2), were isolated from the tuber of Sparganium stoloniferum. The structures of both new compounds were determined on basis of spectroscopic means including HR-ESI-MS, 1D and 2D NMR experiments.     

Anti-emetic Principles of Water Extract of Brazilian Propolis

ABSTRACT

Water extract of Brazilian propolis showed anti-emetic activity on copper sulfate–induced emesis in young chicks. Bioassay-guided fractionation of the extract was carried out, and dehydrohautriwaic acid (1), (E.)-3-(2,2-dimethyl-2H.-1-benzopyran-6-yl)-2-propenoic acid (2), dihydrocinnamic acid (3), (Z.)-3-(2,2-dimethyl-2H.-1-benzopyran-6-yl)-2-propenoic acid (4), aromadendrane-4β,10α-diol (5), and lupeol (6) were isolated as the active components.     

One new ergostane-type steroid and three new phthalide derivatives from cultures of the basidiomycete Albatrellus confluens

One new ergostane-type steroid, (12β,15β,22R,23S,24S)-22,25-epoxy-12,15,23-trihydroxyergost-4,6,8(14)-trien-3-one (1), three new phthalide derivatives, 5-(2′,3′-epoxy-3′,3′-dimethylpropoxy)-7-methoxy-6-methylphthalide (2), (2′)-(Z)-5-(3′-hydroxymethyl-3′-methylallyloxy)-7-methoxy-6-methylphthalide (3), and 5-(3′,3′-dimethylallyloxy)-7-hydroxy-6-methylphthalide (4), along with one known phthalide derivative, 5-(3′,3′-dimethylallyloxy)-7-methoxy-6-methylphthalide (5), were isolated from cultures of the basidiomycete Albatrellus confluens. The structures of the new compounds were established on the basis of extensive spectroscopic data (IR, MS, 1D, and 2D NMR) analyses. All compounds were evaluated for their cytotoxic activities on five tumor cell lines.     

Two new flavonoid glycosides from Artemisia frigida Willd.

An investigation of the n-BuOH-soluble fraction from the aerial parts of Artemisia frigida has led to the isolation of two new flavonoid glycosides, named friginoside A and friginoside B. Their structures were characterized as 5,7-dihydroxy-3′,4′,5′-trimethoxy flavone 7-O-β-d-glucuronide (1) and 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone 7-O-β-d-glucuronyl-(1 → 2)O-β-d-glucuronide (2) on the basis of 1D and 2D NMR spectral analysis.     

Ceramides and cerebrosides from the marine bryozoan Bugula neritina inhabiting South China Sea

From the marine bryozoan Bugula neritina inhabiting South China Sea, a new ceramide named (2S,3R,4E)-2-(14′-methyl-pentadecanoylamino)-4-octadecene-l,3-diol (1) and a new cerebroside named 1-O-(β-d-glucopyranosyl)-(2S,3R,4E)-2-(heptadecanoylamino)-4-octadecene-l,3-diol (6), together with one known ceramide (2) and three known cerebrosides (3, 4, and 5), were isolated. Their structures were deduced by extensive spectral analysis and chemical evidences. Compound 1 is branched with a methyl [–CH(CH₃)₂] in the fatty acid moiety, which is a rare structural feature among ceramides. Compound 6 is a new cerebroside with 17 carbons in the fatty acid moiety, while 5 is a new natural product which was isolated from a natural origin for the first time.     

Note: A new compound from Rhododendren anthopogonosides maxim

A new compound, (2R)-4-phenyl-2-O-[β-d-xylopyranosyl(1→6)-β-d-glucopyranosyl]butane (1), has been isolated from the aerial parts of Rhododendren anthopogonoides, together with two known compounds, fraxin (2), and lyoniside (3). Their structures were determined by means of physico-chemical evidence and spectral analyses, including UV, IR, HR-FABMS, ¹H and ¹³C NMR, and 2D NMR data.