Flavone C-glycosides from Viola yedoensis MAKINO

A new flavone C-glycoside, apigenin 6-C-alpha-L-arabinopyranosyl-8-C-beta-L-arabinopyranoside, has been isolated from Viola yedoensis together with the known compounds, apigenin 6,8-di-C-alpha-L-arabinopyranoside, apigenin 6-C-alpha-L-arabinopyranosyl-8-C-beta-D-glucopyranoside (isoschaftoside), apigenin 6-C-beta-D-glucopyranosyl-8-C-alpha-L-arabinopyranoside (schaftoside), apigenin 6-C-beta-D-glucopyranosyl-8-C-beta-L-arabinopyranoside (neoschaftoside), apigenin 6,8-di-C-beta-D-glucopyranoside (vicenin-2), apigenin 6-C-alpha-L-arabinopyranosyl-8-C-beta-D-xylopyranoside, apigenin 6-C-beta-D-xylopyranosyl-8-C-alpha-L-arabinopyranoside, luteolin 6-C-beta-D-glucopyranoside (isoorientin) and luteolin 6-C-alpha-L-arabinopyranosyl-8-C-beta-D-glucopyranoside (isocarlinoside). The structures were determined by spectroscopic methods and new or revised (1)H- and (13)C-NMR spectral assignments are proposed for some compounds.     

Apigenin Ameliorates Scopolamine-Induced Cognitive Dysfunction and Neuronal Damage in Mice

We investigated the protective effect and mechanisms of apigenin against cognitive impairments in a scopolamine-injected mouse model. Our results showed that intraperitoneal (i.p.) injection of scopolamine leads to learning and memory dysfunction, whereas the administration of apigenin (synthetic compound, 100 and 200 mg/kg/day) improved cognitive ability, which was confirmed by behavioral tests such as the T-maze test, novel objective recognition test, and Morris water maze test in mice. In addition, scopolamine-induced lipid peroxidation in the brain was attenuated by administration of apigenin. To further evaluate the protective mechanisms of apigenin on cognitive and memory function, Western blot analysis was carried out. Administration of apigenin decreased the B-cell lymphoma 2-associated X/B-cell lymphoma 2 (Bax/Bcl-2) ratio and suppressed caspase-3 and poly ADP ribose polymerase cleavage. Furthermore, apigenin down-regulated the β-site amyloid precursor protein-cleaving enzyme, along with presenilin 1 (PS1) and PS2 protein levels. Apigenin-administered mice showed lower protein levels of a receptor for advanced glycation end-products, whereas insulin-degrading enzyme, brain-derived neurotrophic factor (BDNF), and tropomyosin receptor kinase B (TrkB) expression were promoted by treatment with apigenin. Therefore, this study demonstrated that apigenin is an active substance that can improve cognitive and memory functions by regulating apoptosis, amyloidogenesis, and BDNF/TrkB signaling pathways.     

A new flavonoid and other constituents from Centaurea nicaeensis All. var. walliana M

A new flavone glucoside, apigenin 4'-(6″-methylglucuronide) (1), together with six known compounds, cirsilineol, jaceosidin, melitensin, apigenin, apigenin 7-(6″-methylglucuronide) and prunasin, were isolated from the ethanolic extract of the aerial parts of Centaurea nicaeensis All. var. walliana M. (Asteraceae) collected from Souk-Ahras, eastern Algeria. The structures were established by spectral analysis, mainly HRESI-MS, UV and 2D-NMR experiments (COSY, HSQC and HMBC).     

Phenolic chemical composition of Petroselinum crispum extract and its effect on haemostasis

From the aqueous extract (Pc) of Petroselinum crispum (Mill) flat leaves specimens were isolated and identified the flavonoids apigenin (1), apigenin-7-O-glucoside or cosmosiin (2), apigenin-7-O-apiosyl-(1 --> 2)-O-glucoside or apiin (3) and the coumarin 2",3"-dihydroxyfuranocoumarin or oxypeucedanin hydrate (4). The inhibitory activity toward clotting formation and platelet aggregation was assessed for Pc flavonoids (1) and (2), and the coumarin (4). Pc showed no inhibition on clotting activity when compared with the control. On the other hand, a strong antiplatelet aggregation activity was observed for Pc (IC50 = 1.81 mg/mL), apigenin (IC50 = 0.036 mg/mL) and cosmosiin (IC50 = 0.18 mg/mL). In all cases ADP was used as inductor of platelet aggregation. Our results showed that Pc, apigenin and cosmosiin interfere on haemostasis inhibiting platelet aggregation. To the best of our knowledge this is the first report for the cosmosiin antiplatelet aggregation in vitro activity.     

Apigenin and Ampicillin as Combined Strategy to Treat Severe Streptococcus suis Infection

As an important zoonotic pathogen, Streptococcus suis (S. suis) can cause a variety of diseases both in human and animals, especially Streptococcal toxic shock-like syndrome (STSLS), which commonly appears in severe S. suis infection. STSLS is often accompanied by excessive production of inflammatory cytokines, which is the main cause of host death. Therefore, it is urgent to find a new strategy to relieve the damage caused by STSLS. In this study, we found, for the first time, that apigenin, as a flavonoid compound, could combine with ampicillin to treat severe S. suis infection. Studies found that apigenin did not affect the growth of S. suis and the secretion of suilysin (SLY), but it could significantly inhibit the hemolytic activity of SLY by directly binding to SLY and destroying its secondary structure. In cell assays, apigenin was found to have no significant toxic effects on effective concentrations, and have a good protective effect on S. suis-infected cells. More importantly, compared with the survival rate of S. suis-infected mice treated with only ampicillin, the survival rate of apigenin combined with an ampicillin-treated group significantly increased to 80%. In conclusion, all results indicate that apigenin in combination with conventional antibiotics can be a potential strategy for treating severe S. suis infection.     

Biotransformation of chrysin and apigenin by Cunninghamella elegans

Biotransformation of chrysin by Cunninghamella elegans NRRL 1392 produced apigenin, apigenin 7-sulfate, apigenin 7,4'-disulfate, and a new metabolite identified as chrysin 7-sulfate. On the other hand, fermentation of apigenin, using the same microorganism, yielded apigenin 7-sulfate and apigenin 7,4'-disulfate. The structures of the metabolites were established by spectral analysis, and acid and enzyme hydrolyses in addition to comparison with reference samples.     

芹菜素的电喷雾萃取电离串联质谱

采用实验室自制的电喷雾萃取电离源(EESI),结合串联质谱(MSn)技术,对芹菜素这一典型的黄酮类活性化合物的质谱行为进行了研究。实验表明,在正、负离子检测模式下,该化合物均能得到较好的EESI-MS信号,且在负离子检测模式下灵敏度更高。通过对比芹菜素的EESI-MS和电喷雾电离质谱(ESI-MS)谱图发现,芹菜素在EESI-MS和ESI-MS中的裂解规律相似,但是EESI是一种比ESI更软的电离模式。根据对芹菜素EESI-MS特征碎片离子的分析,提出了芹菜素在EESI-MS中裂解的基本规律,为EESI-MS技术用于分析、鉴定复杂基质中痕量芹菜素奠定了理论和实验基础。     

RP-HPLC analysis of Jirakadyarishta and chemical changes during fermentation

Jirakadyarishta, an Ayurvedic formulation prepared by the fermentation of a decoction of Cuminum cyminum (seeds) is traditionally used for intestinal disorders. RP-HPLC analysis of the decoction and the final processed formulation revealed that apigenin-7-O-[galacturonide (1 --> 4)-O-glucoside] and luteolin-4'-O-glucoside-7-O-galacturonide) were the two major constituents of the decoction of C. cyminum. Selective hydrolysis of 7-O-glucosides of luteolin and apigenin during fermentation resulted in an increase in the amount of luteolin and apigenin. The 4'-O-glucoside-7-O-galacturonide of luteolin and galacturonide derivative of apigenin were not hydrolyzed during fermentation. Monomeric phenolics, together with 5-hydroxymethyl furfural (5-HMF), were also introduced into the formulation through the jaggery and other plant materials during fermentation. This communication highlights the importance of the ancient processing methods used in Ayurveda.     

Could be radiolabeled flavonoid used to evaluate infection?

The aim of this study was to determine whether [¹³¹I]apigenin is a powerful and discrimination infection from inflammation for scintigraphic imaging. The study was carried out in inflamed rats with Staphylococcus aureus (S. aureus) and sterile inflamed rats with turpentine oil. Biodistribution study of [¹³¹I]apigenin was performed in the rats. Apigenin was labeled with ¹³¹I by iodogen method. Obtained [¹³¹I]apigenin with high yield (98%) was injected i.v. to both group rats. The results were expressed as the percent uptake of injected dose per gram of organ (%ID/g), the bacterial infected and sterile inflamed muscles. Binding of [¹³¹I]apigenin to the infected thigh muscle (target muscle = T) and normal thigh muscle (non-target muscle = NT) ratio (T/NT = 4.51 at 15 min) was higher than binding to bacterial inflamed muscle (T/NT = 2.25 at 15 min) of rats. [¹³¹I]apigenin showed good localization in both inflamed tissues. This uptake in the sterile inflamed tissue is higher than bacterial infected tissue. [¹³¹I]apigenin might be useful for imaging of inflamed tissues. However, it is not discriminate sterile inflamed tissue from bacterial infected tissue.     

New cytotoxic flavonoids from aerial parts of Platycladus orientalis L.

Abstract

Investigation of Platycladus orientalis yielded five flavonoids, including aglycone flavone 1 (apigenin), flavone glycoside 2 (apigenin 7-O-β-D-glucopyranoside), new gernaylated flavone glycoside 3 (apigenin 8-gernayl-4′-O-α-gluco pyranoside) and two new pernylated flavonoid glycosides 4 & 5 (apigenin 8-pernyl-4′-glucopyranosyl-7-O-α-glucopyranoside and apigenin 5-pernyl-7-glucopyranosyl-4′-O-β-D-glucopyranoside). Their structures were elucidated on the basis of spectroscopic evidence. The cytotoxicity of compounds 1–5 were tested against Lung adenocarcinoma (A549), human hepatocellular liver carcinoma (HepG2), human breast carcinoma (MCF-7) cell lines and mouse fibroblast cell line NIH/3T3 as normal cells. This assay gave spot on structure activity relationship which, showed that cytotoxicity of compounds (1) and (2) against three cell lines was weak as IC₅₀?>?15. Compounds (4) and (5) had moderate cytotoxic and no toxic effect on normal cell. Compound (3) showed high cytotoxic activity against tested three cell lines with no toxic effect of normal cells.

     

STUDY ON THE NON-COVALENT INTERACTION OF APIGENIN MOLECULARLY IMPRINTED POLYMERS BY SPECTROMETRY

The non-covalent interaction between aPigenin （API） and different functional monomers （α-methylacrylic acid （MAA）, acrylamide （AM）, 2-vinylpyridine （2-Vpy） and combined functional monomers （AM/2-Vpy）） was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers （API-MIPs） was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran （THF） is as follows： 2-Vpy〉 AM/2-Vpy〉AM〉MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.     

吡嗪二甲酰胺桥联芹菜素铜配合物的合成及其DNA切割活性

以5,6-二甲基-2,3-吡嗪二甲酰胺和芹菜素为混合配体,与醋酸铜以溶剂热法合成吡嗪二甲酰胺桥联芹菜素铜配合物;该配合物通过紫外光谱、红外光谱、差热-热重分析及X射线粉末衍射(XRD)等进行表征。采用酶切实验及琼脂糖凝胶电泳法,研究该铜配合物对DNA的切割活性;凝胶电泳结果表明,不加入任何还原剂时,当质量浓度为0.0592 g/L时,该配合物对超螺旋p BR 322DNA表现出显著的DNA切割活性,且随质量浓度的增加,切割活性增强。这为人工核酸酶的研究提供了例证及开阔了思路。     

Isolation of onosmins A and B, lipoxygenase inhibitors from Onosma hispida

Onosmins A (1) and B (2), lipoxygenase inhibitors, have been isolated from Onosma hispida. Their structures were established as 2-[(4-methylbenzyl)amino]benzoic acid (1) and methyl 2-[(4-methylbenzyl)amino]benzoate (2) through spectroscopic studies, including 2D-NMR. The known compounds apigenin (3), 6,4'-dimethoxy-3,5,7-trihydroxyflavone (4), 6,7-dimethoxy-3,5,4'-trihydroxyflavone (5) and apigenin 7-O-beta-D-glucoside (6) are also reported for the first time from this species. Compounds (1) and (2) inhibited lipoxygenase (LOX, EC 1.13.11.12) enzyme in a concentration-dependent fashion with IC50 values of 24.0 and 36.2 microM, respectively. Lineweaver-Burk as well as Dixon plots and their secondary replots indicated that the nature of inhibition was purely a non-competitive type, with K(i) values 22.0 microM and 31.1, respectively.     

Kinetics studies on flavone glycosides: inhibitors of <Emphasis Type="Italic">α</Emphasis>-chymotrypsin

The mechanism of inhibition of α-chymotrypsin enzyme by two flavone glycosides having an apigenin basic skeleton, namely, apigenin 7-O-β-D(-6′′-p-E-coumaroyl)-glucoside (1) and apigenin 7-O-β-D-glucoside (2), isolated from Clematis orientalis L. (Ranunculaceae), was investigated. Lineweaver-Burk and Dixon plots and their secondary replots have shown that both of the compounds are competitive inhibitors of this enzyme. K_i values for 1 and 2 were found to be 71.75 ± 0.85 and 680.11 ± 0.11 μM, respectively.     

固相萃取/液相色谱-质谱/质谱法测定山银花中5种主要黄酮苷元的含量

该文通过含有盐酸的乙醇溶液回流水解并提取,HLB固相萃取柱净化,液相色谱-质谱/质谱法检测,建立了山银花中槲皮素、木犀草素、山萘酚、芹菜素和黄芩素5种黄酮苷元含量的测定方法。实验以芦丁、木犀草苷、紫云英苷、野漆树苷和黄芩苷5种黄酮苷为代表开展研究,山银花样品经50%的乙醇溶液(含10%浓盐酸)回流2 h水解黄酮苷,同时对黄酮苷元进行提取,HLB固相萃取柱净化,采用Mightysil RP-18色谱柱分离,液相色谱-质谱/质谱法检测(电喷雾离子源、多反应监测模式、负离子扫描),外标法定量测定水解后的5种黄酮苷元含量。方法的定量下限(S/N=10)为0.005 g/kg(槲皮素),0.01 g/kg(木犀草素和芹菜素)和0.05 g/kg(山萘酚和黄芩素)。在0~1.0 g/kg范围内,5种黄酮苷元的线性相关系数均大于0.995;在山银花样品中对待测物进行3种加标水平的回收实验(加标水平相当于水解后槲皮素和木犀草素含量为:0.10、0.20、0.40 g/kg,山萘酚、芹菜素和黄芩素含量为:0.05、0.10、0.20 g/kg),方法的平均回收率70.4%~104%;相对标准偏差为4.0%~12%。该方法实现了山银花中多种主要黄酮苷元含量的同时测定,且对研究山银花药效及与黄酮类化合物的关系具有重要意义。     

Constituents of the Whole Herb of Clinoponium laxiflorum

The isolation and identification of twenty‐two components (including one new compound) from the whole herb of Clinoponium laxiflorum (Hay) Matsum (Labiatae) are described. Their structures were determined on the basis of spectral and chemical transformation. One new compound is methyl rosmarinate. The other twenty‐one compounds include three steroids (α‐spinasterol, α‐spinasteryl‐3‐O‐β‐D‐glucopyranoside, and β‐sitosteryl‐3‐O‐β‐glucopyranoside), three triterpenes (oleanolic acid, ursolic acid, and betulinic acid), nine flavonoids (didymin, apigenin‐7‐O‐β‐glucopyranoside, luteolin‐7‐O‐β‐glucopyranoside, isosakuranetin, narigenin, apigenin, luteolin, narirutin, and hesperidin), three lignolic acids (rosmarinic acid, 3‐(3,4‐dihydroxyphenyl)lactic acid, and caffeic acid), and three phenols (4‐hydroxybenzaldehyde, 3,4‐dihydroxybenzaldehyde, and 3,4‐dihydroxybenzoic acid).     

Two new alkaloids from Capparis himalayensis

Two new alkaloids, Capparin A (1) and B (2), along with seven known compounds 6-methoxyindoline-2,3-dione (3), wogonin (4), oroxylin A (5), kaempferol (6), apigenin (7), quercetin (8) and luteolin (9), were isolated from the whole plant of Capparis himalayensis. Their structures have been established on the basis of spectral methods and the structure of 1 was confirmed by X-ray crystallographic analysis.     

Simultaneous determination of polyphenols and major purine alkaloids in Greek Sideritis species, herbal extracts, green tea, black tea, and coffee by high-performance liquid chromatography-diode array detection

Herein, a high-performance liquid chromatography-diode array detection method has been developed for the simultaneous determination of 15 phenolic antioxidants: flavan-3-ols, (-)-epigallocatechin, (+)-catechin, (-)-epigallocatechin gallate, (-)-epicatechin, (-)-epicatechin gallate, (-)-gallocatechin, a phenolic acid (gallic acid), a hydroxycinnamic acid (chlorogenic acid), flavones (apigenin), flavonols (kaempferol, quercetin, and myricetin), and purine alkaloids (caffeine theophylline, theobromine) in different herb extracts, tea, and coffee varieties. The developed method was validated and successfully applied in order to determine the polyphenolic content to estimate the antioxidant activity of the Sideritis species commonly known as Greek mountain tea. To the best of our knowledge, this is the first report on the quantitative determination of catechins and other polyphenols in Greek mountain tea. Acidic hydrolysis was necessary for the simultaneous determination of the aglycones of the target analytes. According to our results, chlorogenic acid, myricetin, apigenin, catechin, and epicatechin gallate are found in the Sideritis species.     

Measurement and correlation of solubilities of apigenin and apigenin 7-O-rhamnosylglucoside in seven solvents at different temperatures

The solubilities of apigenin and apigenin 7-O-rhamnosylglucoside in water, methanol, ethanol, 1-propanol, 1-butanol, acetone, and ethyl acetate from T = (288.2 to 328.2) K were measured. The solubilities of apigenin and apigenin 7-O-rhamnosylglucoside in selected solvents increase with increasing temperature, respectively. The experimental solubility data were correlated by a simplified thermodynamic equation and a three-parameter empirical equation.     

New cytotoxic apigenin derivatives from Selaginella doederleinii

75%aqueous ethanol extract from the whole herbs of Selaginella doederleinii was isolated,and two new apigenin derivatives,doederflavones A(1) and B(2),together with ten known compounds(3-12) were characterized.Their structures were assigned by extensive spectroscopic methods including 1D/2D NMR and HR-ESIMS.Compounds 1-6 bear an aryl substituent at the C-8 or C-6 positions in ring A of apigenin skeleton.Compounds 1 and 2 were evaluated for their in vitro cytotoxicity against four human cancer cell lines A549,MCF-7,SMMC-7721,and LoVo,both of which exhibited significant cytotoxicity against A549 with IC_(50) values of 0.82 μmol/L and 1.32 μmol/L,respectively.