Polyphenolic compounds from Platycodon grandiflorum A. DC

Flavonoids and phenolic acids from the aerial parts of Platycodon grandiflorum A. DC. were analysed by isocratic TLC, MGD-TLC and HPLC methods. Four flavonoid compounds were determined including luteolin 7-O-glucoside as the main component and apigenin 7-O-glucoside, luteolin and apigenin. When performing HPLC analysis, 12 phenolic acids in the free, depside and glycoside forms were identified. Among them, 3,4-dimethoxycinnamic, caffeic, chlorogenic, ferulic, isoferulic, homovanillic, alpha-resorcylic, m-coumaric, p-coumaric, p-hydroxybenzoic, 2-hydroxy-4-methoxybenzoic and 2,3-dihydroxybenzoic acids.     

Constituents of Cynara syriaca. Leaves

Abstract

Six flavonoids (apigenin, chrysoeriol, luteolin, apigenin 7-O.-glucoside, chrysoeriol 7-O.-glucoside, luteolin 7-O.-glucoside), four phenolic acids (caffeic acid, chlorogenic acid, 1,5-dicaffeoylquinic acid, cynarin), and three sesquiterpene lactones (11,13-dihydroxy-8-desoxygrosheimin, 11,13-dihydrodeacylcynaropicrin, solstitialin) were isolated from the leaves of Cynara syriaca. Boiss (Asteraceae). Three of these compounds, chrysoeriol, chrysoeriol 7-O.-glucoside, and 11,13-dihydrodeacylcynaropicrin, were isolated for the first time from Cynara. species. 11,13-Dihydroxy-8-desoxygrosheimin was isolated for the second time from a plant.     

Flavonoids from lemon balm (Melissa officinalis L., Lamiaceae)

Six flavonoids have been isolated from the leaves of lemon balm (Melissa officinalis L., Lamiaceae). Their structures were determined on the basis of spectral data (UV, 1R, 1H NMR, 13C NMR and FAB MS) as luteolin, luteolin 7-O-beta-D-glucopyranoside, apigenin 7-O-beta-D-glucopyranoside, luteolin 7-O-beta-D-glucuronopyranoside, luteolin 3'-O-beta-D-glucuronopyranoside and luteolin 7-O-beta-D-glucopyranoside-3'-Obeta-D-glucuronopyranoside. The last three glycosides have been found in lemon balm for the first time and luteolin 7-O-beta-D-glucopyranoside-3'-O-beta-D-glucuronopyranoside is a new compound found in plants.     

Flavonoids of Cynara scolymus possess potent xanthinoxidase inhibitory activity in vitro but are devoid of hypouricemic effects in rats after oral application

Artichoke (Cynara scolymus L.) leaves have been historically used for the treatment of hyperuricemia and gout, however whether artichoke is truly efficacious for this indication, is still a matter of debate. Thus, the goal of the present study was first to examine the xanthine oxidase (XO) inhibitory activity of an artichoke leaf extract (ALE) and some of its main compounds in vitro and then further test potentially active substances for possible hypouricemic effects using an in vivo rat model. The in vitro study showed that ALE inhibited XO with only minimal inhibitory action (< 5 %) at 100 microg/mL. However, when selected compounds were tested, the caffeic acid derivatives revealed a weak XO inhibitory effect with IC (50) > 100 microM. From the tested flavones the aglycone luteolin potently inhibited XO with an IC (50) value of 1.49 microM. Luteolin 7-O-glucoside and luteolin 7-O-glucuronide showed lower XO inhibition activities with IC (50) values of 19.90 microM and 20.24 microM, respectively. However, oral administration of an aqueous ALE, luteolin, and luteolin 7-O-glucoside did not produce any observable hypouricemic effects after acute oral treatment in potassium oxonate-treated rats. After intraperitoneal injection of luteolin a decrease in uric acid levels was detected suggesting that the hypouricemic effects of luteolin are due to its original form rather than its metabolites produced by the gut flora. In conclusion, an aqueous ALE, caffeic acid derivatives and flavones exerted XO inhibitory effects in vitro but a hypouricemic activity could not be confirmed after oral administration.     

Phenolic compounds from two Melampyrum species

Flavonoids and phenolic acids isolated from the herbs of Melampyrum pretense (MP) and M. nemorosum (MN) (Scrophulariaceae) growing in the Ural region have been studied by two-dimensional paper chromatography. The phenolic complex of MP contains 23 compounds including 17 flavonoids and 6 phenolcarboxylic acids. The MN herb contains 9 flavonoids and 5 phenolcarboxylic acids. A comparison with reference samples showed the presence of cinaroside, luteolin, quercetin, hyperoside, and chlorogenic, caffeic, and ferulic acids. Differential UV spectra of the extracts of MP and MN herbs in the presence of aluminum chloride showed peaks at 395.6 and 398.7 nm, respectively, which have been used for quantitative determination of the flavonoids (recalculated for cinaroside). The maximum flavonoid content was found in the generative organs; the minimum, in the roots. It is established that the flavonoid content in various organs varies within 0.08–3.17% for MP and 0.04–2.29% for MN.     

The aromatic and polyphenolic composition of lemon balm (Melissa officinalis L. subsp. officinalis) tea

The chemical composition of the widely used herbal tea made from lemon balm (Melissa officinalis L. subsp. officinalis) was previously unknown. The qualitative and quantitative composition of the main aromatic and polyphenolic constituents of the infusion were examined and compared with those of the leaves before and after infusion. The dried lemon balm leaves originally contained 0.32% essential oil of which citral (neral + geranial) 0.13%, total polyphenol compounds 11.8% comprising total hydroxycinnamic compounds 11.3% (rosmarinic acid 4.1%) and total flavonoid compounds 0.5%. The tea contained 10 mg/l of essential oil (extraction yield 31%) with much more citral (74% of the essential oil). It also contained large amounts of polyphenol compounds (about 1.07 g/l) corresponding to a 93% extraction yield.     

Flavonoids in the flowers of Primula officinalis

From methanolic extracts of fresh flowers of PRIMULA OFFICINALIS 19 flavonoids were isolated or detected: quercetin, luteolin, kaempferol, isorhamnetin, apigenin; quercetin 3-O-glucoside, -rutinoside, -robinobioside, -gentiobioside, -(glucosyl-(1-->2) -glucosyl-(1-->6))-glucoside, -(rhamnosyl)-robinobioside; isorhamnetin 3-O-glucoside, -rutinoside, -robinobioside, -(rhamnosyl) -robinobioside; kaempferol 3-O-rutinoside, -robinobioside; limocitrin 3-O-glucoside; 3', 4'-dihydroxyflavonglucoside. Other compounds isolated were epicatechin, epigallocatechin, and proanthocyanidin B 2.     

Flavonoids and Fatty Acids of Dicliptera roxburghiana

Abstract

Saturated fatty acids (C-15 to C-31) and flavonoids (apigenin, kaempferol luteolin and apigenin-7-O-glucoside) have been isolated and identified from Dicliptera roxburghiana.     

Identification and quantitative analysis of phenolic compounds from the dry extract of Hedera helix

A thorough investigation of phenolic constituents of commercial dry extract of Hedera helix L. (Araliaceae) was carried out. Rutin (1), kaempferol 3-O-rutinoside (2), quercetin 3-O-glucoside (isoquercitrin, 5), and kaempferol 3-O-glucoside (astragalin, 12), quercetin (10), kaempferol (11), chlorogenic acid (3), neochlorogenic acid (4), 4,5- (6) and 3,5-O-dicaffeoyl-quinic (7) acids as well as rosmarinic (13), caffeic (8), and protocatechuic (9) acids were isolated and identified by spectroscopic methods. Compounds 4, 6, 7, 12, and 13 are reported for the first time for H. helix. Six main phenolics (1 -3, 6, 7, 9) were quantified by means of HPLC and capillary electrophoresis (CE).     

High-performance liquid chromatography of flavonoids in Crataegus oxyacantha L. IV. Reversed-phase high-pressure liquid chromatography in flower, leaf and bud extractives of Crataegus oxyacantha L

RP-HPLC has been used for qualitative and quantitative analysis of some flavonoids in flowers, leaves and bud extracts of Crataegus oxyacantha L. Peak identification was obtained by comparison with retention times of pure standard substances and by UV analysis. Luteolin, luteolin-3', 7-diglucoside, apigenin, apigenin-7-O-glucoside and rutin have been identified and determined.     

Influence of biotransformation of luteolin, luteolin 7-O-glucoside, 3',4'-dihydroxyflavone and apigenin by cultured rat hepatocytes on antioxidative capacity and inhibition of EGF receptor tyrosine kinase activity

Flavonoids are known as biologically active compounds. Although this has been shown by several in vivo studies, it is still elusive whether their metabolites exert similar activities. Herein we investigated the biotransformation of four different flavonoids, 3',4'-dihydroxyflavone, apigenin, luteolin and luteolin 7-O-glucoside, by cultured rat hepatocytes using a combination of enzymatic deconjugation, HPLC separation and high-resolution mass spectrometry. These flavonoids were chosen because they are active components of many plants, e. g., artichokes. All flavonoids showed rather complex metabolite patterns dominated by phase II metabolites, mainly sulfates, methyl sulfates and methyl glucuronides, but also of combined glucuronide and sulfate conjugates. Phase I metabolism by hydroxylation was rendered likely only for apigenin to form luteolin. When culture media containing the flavonoids and their metabolites were assayed for antioxidative capacity by the DPPH assay, only compounds with hydroxy groups in position 3' and 4' of the B ring were active. Thus, during metabolism of (inactive) apigenin a strong increase in the antioxidative effect was observed while that of the other three flavonoids decreased with time. Determination of EGF receptor tyrosine kinase activity likewise revealed strong inhibition in the presence of a catechol group at ring B. However, in this case the situation was much more complex resulting in a significant increase of the inhibitory activity of 3',4'-dihydroxyflavone and apigenin, but not of luteolin and luteolin 7-O-glucoside during 22 h of incubation. These results show that the biotransformation of flavonoids is very complex and may result not only in a loss but also in a gain of biological activity depending on the individual structural features.     

Chemical constituents from Matricaria chamomilla L. (I)

In the present study, we aimed to perform a phytochemical investigation of the whole herb of Matricaria chamomilla L., a Uygur herbal medicine. A total of 18 phenolic compounds were isolated by silica gel and Sephadex LH-20 chromatography, together with preparative HPLC methods. By analysis of the MS and NMR spectroscopic data and comparison with those in literature, these 18 compounds were identified as apigenin (1), galangin (2), luteolin (3), kempherol (4), quercetin (5), hispidulin (6), 6-methoxykaempferol (7), eupafolin (8), 3-methylquercetin (9), ermanin (10), 5,7,4′-trihydroxy-3,6-dimethoxyflavonone (11),bracteoside (12), 7-O-(β-D-glucopyranosyl)-galactin (13), isochlorogenic acid B (14), isochlorogenic acid C (15), 4-hydroxybenzoic acid (16), 5-pentadecylbenzene-1,3-diol (17) and scopoletin (18). Among them, compounds 1–13 were identified as flavonoids. Compounds 2 and 6–17 were isolated from both the plant and the Matricaria genus for the first time.     

复方仙鹤草肠炎胶囊的主要有效成分及其治疗肠炎靶点的筛选

目的:筛选复方仙鹤草肠炎胶囊中的主要有效成分及其治疗肠炎靶点。方法:采用超高效液相色谱-串联质谱技术(UHPLC-MS/MS)、MWDB数据库和相关文献分析鉴定复方仙鹤草肠炎胶囊甲醇提取物中的主要化学成分。通过中药系统药理学分析平台(TCMSP)、PubChem、UniProt数据库预测和筛选该制剂的活性成分及其潜在靶点;借助GeneCards和OMIM数据库预测和筛选肠炎相关靶点;采用R语言4.0.2筛选两者共同靶点。将共同靶点对应的化学成分与该制剂甲醇提取物中的化学成分进行匹配,获取该制剂的主要有效成分。借助STRING数据库和Cytoscape 3.7.1软件构建共同靶点的蛋白质-蛋白质相互作用网络,以节点度值筛选该制剂的关键靶点。结果:共鉴定出化合物48个,包括酚酸类化合物13个、生物碱类化合物10个、黄酮类化合物8个、萜类化合物6个、其他类化合物6个、脂质类化合物3个、鞣质类化合物1个、有机酸类化合物1个;对比网络药理学数据,推测芹菜素、木犀草素、槲皮苷类(含3,7-二氧-甲基槲皮素、槲皮素-3-O-β-D-半乳糖苷、槲皮素-7-O-葡萄糖苷、槲皮素3-O-β-D-葡萄糖苷)、掌叶防己碱、原儿茶酸-4-葡萄糖苷和3,4-二甲氧基肉桂酸等均为其主要有效成分,治疗肠炎的关键靶点包括转录因子p65(RELA)、淀粉样β/A4蛋白(APP)、G1/S特异性细胞周期蛋白D1(CCND1)、表皮生长因子受体(EGFR)、胰岛素(INS)、雌激素受体(ESR1)、白细胞介素6(IL6)、核受体共激活剂1(NCOA1)、胱天蛋白酶8(CASP8)、原癌基因c(FOS)等。结论:共挖掘出复方仙鹤草肠炎胶囊中的主要有效成分9个(包括芹菜素、木犀草素、槲皮苷类等)及其治疗肠炎的关键靶点10个(包括RELA、APP、CCND1等)。     

苦碟子中的两个新黄酮苷

从苦碟子（Ixeris sonchifolia Hance)的全草中分得5个黄酮,分别为木犀草素－7－O－β－D－葡萄糖醛酸苷甲酯（1）,芹菜素－7－O－β－D－葡萄糖醛酸苷甲酯（2）,木犀草素（3）,木犀草素－7－O－β－D－葡萄糖苷（4）,芹菜素（5）。它们的结构经各种光谱解析确定,其中化合物1和2为新黄酮。     

Chemical fingerprint and quantitative analysis of Salvia plebeia R.Br. by high-performance liquid chromatography

To control the quality of Salvia plebeia R.Br., a simple and reliable method of high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD) was developed both for fingerprint analysis and quantitative determination of seven bioactive compounds, namely caffeic acid, luteolin-7-glucoside, nepetin-7-glucoside, homoplantaginin, luteolin, nepetin and hispidulin. In fingerprint analysis, twelve peaks were selected as characteristic peaks. In quantitative analysis, seven compounds showed good regression (R(2)>0.9995) within test ranges and the recovery of the method was in the range of 91.7-103.2%. The content ranges (mg/g) of seven compounds in the collected samples of S. plebeia were 0.80-1.67 (hispidulin), 2.18-5.75 (homoplantaginin), 0.52-1.22 (nepetin), 1.56-3.48 (nepetin-7-glucoside), 0.12-0.24 (luteolin), 0.97-2.22 (luteolin-7-glucoside) and 0.21-0.44 (caffeic acid), respectively. From the results obtained, the content of homoplantaginin was the highest. In addition, luteolin and luteolin-7-glucoside were isolated for the first time from S. plebeia.     

Evaluation of hepatic clearance and drug-drug interactions of luteolin and apigenin by using primary cultured rat hepatocytes

The hepatic clearance and drug-drug interactions of luteolin and apigenin were studied by using primary cultured rat hepatocytes. Luteolin and apigenin experienced extensive first-pass metabolism. The elimination percent of luteolin and apigenin was found to be 91.9% and 86.7% after 120 min of incubation. The predicted % liver blood flow was 82.3% and 85.4% for luteolin and apigenin, respectively. Total glucuronidated/sulfated conjugates of luteolin/apigenin were determined by an enzyme hydrolysis method. Compared with the elimination of pure luteolin and apigenin, the elimination of luteolin and apigenin was much lower in hydrolyzed Flos Chrysanthemi extract (FCE) containing comparable amounts of luteolin and apigenin. The effect of a series of flavonoids, including flavonols, flavones, isoflavone, flavanone, flavanonols and catechins, on the elimination of luteolin and apigenin was studied. At least four key determinants in the chemical structures of flavonoids are necessary for exerting the inhibitory effects on the conjugation: 1) catechol structure (3',4'-dihydroxylation) in the B-ring; 2) B-ring is attached to the C-2 position on the C-ring; 3) the C2-3 double bond in conjunction with the C4 carbonyl group on the C-ring; 4) no glycoside present. Investigation of clearance and interaction among flavonoids could help us better understand their bioavailability and offer insight into the approaches to be taken to minimize competitive effects, and to design appropriate bioavailability studies in humans.     

In vitro effects of selected flavonoids on the 5'-nucleotidase activity.

A series of structurally related flavonoids and related compounds were evaluated whether they have inhibitory properties on the 5'-nucleotidase (5'-ribonucleotide phosphohydrolase; EC 3.1.3.5, 5'-NT) activity. Some of the flavonoids tested inhibit the enzyme such as quercetin, morin, apigenin, chrysin, myricetin, luteolin, diosmetin, (+/-)naringenin and diosmin. Rutin, naringin, hyperosid, (+/-)catechin, caffeic acid and rosmarinic acid had no inhibitory effect on the 5'-NT activity. Myricetin and quercetin were the most potent inhibitors for 5'-NT with IC50 values of 1.1 and 1.4 microM, respectively. Kinetic analysis showed a mixed type of inhibitor for both myricetin (Ki = 1.5 microM at pH 7.45), and quercetin (Ki = 0.6 microM at pH 7.45). The K(m) value for 5'-adenosine monophosphate (5-AMP) was determined with 77 microM at pH 7.45. The differential inhibitory potencies of flavonoids seem to be structurally related (hydroxylation pattern). The results demonstrate that some flavonoids are strong inhibitors of 5'-NT activity which can be correlated to their pharmacological effects.     

Metabolic profile of the bioactive compounds of burdock (Arctium lappa) seeds, roots and leaves

In this work the bioactive metabolic profile, the antioxidant activity and total phenolic content of burdock (Arctium lappa) seeds, leaves and roots were obtained. TEAC values and total phenolic content for hydro-alcoholic extracts of burdock ranged from 67.39 to 1.63 μmol Trolox equivalent/100 g dry weight (DW), and from 2.87 to 45 g of gallic acid equivalent/100 g DW, respectively. Phytochemical compounds were analyzed by liquid chromatography coupled to electrospray tandem mass spectrometry (LC/MS/MS) in negative mode. The main compounds of burdock extracts were caffeoylquinic acid derivatives, lignans (mainly arctiin) and various flavonoids.The occurrence of some phenolic acids (caffeic acid, chlorogenic acid and cynarin) in burdock seeds; arctiin, luteolin and quercetin rhamnoside in burdock roots; phenolic acids, quercetin, quercitrin and luteolin in burdock leaves was reported for the first time.     

Effect of oral treatment of Perilla frutescens and its constituents on type-I allergy in mice

Perilla frutescens Britton (perilla, Labiatae) is a medicinal herb prescribed in Saiboku-to [Japanese letters: see text], which is a Kampo formula effective for allergic diseases such as bronchial asthma. The present study was conducted to evaluate the anti-allergic effect of orally administered perilla decoction and to identify the active constituents using mice ear-passive cutaneous anaphylaxis (PCA)-reaction, which is one of the animal models for type I allergy. Perilla decoction significantly suppressed PCA-reaction, and the inhibition % at the dose of 500 mg/kg was 43%. The perilla decoction contains 5.3% of luteolin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide], 1.6% of apigenin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide], 0.49% of scutellarin, and 2.5% of rosmarinic acid (weight of compound/dried weight of perilla decoction %), respectively. When these constituents were orally administered to mice at the dose equivalent to 500 mg/kg of perilla decoction, rosmarinic acid and apigenin 7-O-[beta-glucuronosyl(2-->1)beta-glucuronide] significantly suppressed PCA-reaction, and their inhibition % was 41% (p<0.01) and 32% (p<0.05), respectively. Since the inhibition % or perilla decoction and rosmarinic acid were nearly equal, the anti-allergic effect of perilla decoction depends primarily on rosmarinic acid. The standard Saiboku-to decoction contained 0.013% of rosmarinic acid, which was too low to exhibit anti-allergic activity in a daily dose of Saiboku-to in adults, suggesting that perilla would be prescribed in Saiboku-to to exhibit other pharmacological effects than its anti-allergic activity, such as a sedative.     

Inhibitory effect of decoction of Perilla frutescens on cultured murine mesangial cell proliferation and quantitative analysis of its active constituents

The leaves of Perilla frutescens (perilla) are a common herb used in Japan for garnishing raw seafood. Previously, we reported that a decoction of perilla leaves had suppressive effects on the progression of glomerulonephritis in an animal model of spontaneous IgA nephropathy. The objective of the present study was to isolate anti-nephritic constituents in the perilla decoction under the guidance of its in vitro anti-proliferative activity on cultured murine mesangial cells, and to measure the contents of the active constituents in decoctions prepared from various perilla chemotypes, which differ in their composition of essential oils and/or pigments. DNA synthesis of cultured mesangial cells induced by 1% fetal calf serum was significantly inhibited by the perilla decoction (IC50 values, 8.8 microg/ml). Caffeic acid, luteolin 7-O-[beta-glucuronosyl(1-->2)beta-glucuronide], apigenin 7-O-[beta-glucuronosyl(1-->2)beta-glucuronide], scutellarin, and rosmarinic acid were isolated as active constituents. The contents of these phenolic compounds were not significantly different among chemotypes of P. frutescens. Considering the relation between the contents in the perilla decoction and the activities of these compounds, rosmarinic acid represents the in vitro anti-proliferative effect of perilla decoction.