Antioxidant flavonoids and chlorogenic acid from the leaves ofEriobotrya japonica

The antioxidant activity of Eriobotrya japonica was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and lipid peroxidation produced when mouse liver homogenate was exposed to the air at 37 degrees C, using 2-thiobarbituric acid (TBA). The methanol extract and its fractions of Eriobotrya japonica leaves showed strong antioxidant activity. The antioxidant activity of EtOAc and n-BuOH soluble fractions were stronger than the others, and were further purified by repeated silica gel, MCl gel CHP-20P, and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid, quercetin-3-sambubioside from n-BuOH fraction, and methyl chlorogenate, kaempferol- and quercetin-3-rhamnosides, together with the inactive ursolic acid and 2 alpha-hydroxyursolic acid from EtOAc fraction were isolated. Antioxidant flavonoids and chlorogenic acid also showed prominent inhibitory activity against free radical generation in dichlorofluorescein (DCF) method.     

Antioxidant activities of the essential oils and methanol extracts from myrtle (Myrtus communis var. italica L.) leaf,stem and flower

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of α-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50 mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, β-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.     

Stability and antioxidant activity of polyphenols in extracts of Myrtus communis L. berries used for the preparation of myrtle liqueur

Flavonoids and anthocyanins in berry extracts from Myrtus communis, prepared by following a typical Sardinia myrtle liqueur recipe, were identified by HPLC coupled with Electrospray Mass Spectrometry and quantified by HPLC coupled with Ultraviolet/Visible Detection in order to evaluate the stability of the extracts during 1 year of storage. Antioxidant activity was measured by using TEAC assay, and the free-radical scavenging activity was monitored during time of the stability evaluation.

Anthocyanins have found to be the most instable compounds, but a considerable instability was observed also for flavonoids, suggesting the use of extracts not over 3 months from their preparation. The myrtle extract showed interesting free-adical scavenging activity. Antioxidant activity was preserved in 3 months.     

Stability and antioxidant activity of polyphenols in extracts of Myrtus communis L. berries used for the preparation of myrtle liqueur

Flavonoids and anthocyanins in berry extracts from Myrtus communis, prepared by following a typical Sardinia myrtle liqueur recipe, were identified by HPLC coupled with Electrospray Mass Spectrometry and quantified by HPLC coupled with Ultraviolet/Visible Detection in order to evaluate the stability of the extracts during 1 year of storage. Antioxidant activity was measured by using TEAC assay, and the free-radical scavenging activity was monitored during time of the stability evaluation.Anthocyanins have found to be the most instable compounds, but a considerable instability was observed also for flavonoids, suggesting the use of extracts not over 3 months from their preparation. The myrtle extract showed interesting free-adical scavenging activity. Antioxidant activity was preserved in 3 months.     

Bioactivity of compounds isolated from the leaves of the Lantana camara Linn plant

Two compounds with different bioactivitieswere isolated from the leaves of the Lantana camara Linn plant. Compound 1wastriterpenoid (Lantadene B)(22β-dimethylacroyloxy-3-oxoolean-12-en-28-oic-acid, C₃₅H₅₂O₅), which was isolatedfrom n-hexane fraction and obtained as white solid (amorphous). Compound 2was glycosideflavonoid (5-hydroxy-6,4′-dimethoxyflavon-7-O-glucopyranose, C₂₃H₂₄O₁₁), which was isolated from ethyl acetate and obtained as pale yellow solid (amorphous). Extraction was performed withmaceration method using methanol solvent. Subsequently, fractionation was carried out using n-hexane and ethyl acetate solvents. Isolation and purification of both fractions were conductedusing chromatography method. The structure of the isolated compounds was determined throughspectralanalyses of ultraviolet (UV), infrared (IR), and nuclear magnetic resonance (¹H NMR and ¹³C NMR), distortionless enhancement by polarization transfer (DEPT), heteronuclear multiple bond connectivity (HMBC), heteronuclear single quantum correlation (HSQC), and H-H COSY (¹H-¹H homonuclear correlatedspectroscopy). The cytotoxic activity of compound 1 was tested against MCF-7 breast cancer cellsin vitro using MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), showing very strong cytotoxic activity in inhibiting the growth of MCF-7 breast cancer cells, and the IC₅₀ value was 1.1336 µM. The antioxidant activity of compound 2 was tested using DPPH assay (1,1-diphenyl-2-picrylhydrazyl), showing strong activity in inhibiting free radicals, and its IC₅₀ value was 71.03 mg/L.     

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.     

Polyphenolic compounds from the leaves of Koelreuteria paniculata Laxm

From the fresh leaves of Koelreuteria paniculata Laxm (Sapindaceae), four new compounds, named ethyl p-trigallate (1), 3'-O-galloyl-4'-O-galloyl-4-O-galloyl-gallic acid (2), ethyl p-heptagallate (3) and 3'-galloylquercitrin (4), together with 12 known compounds namely catechin (5), galloylepicatechin (6), isorhamnetin (7), kaempferol-3-O-arabinopyranoside (8), quercetin-3'-O-beta-D-arabinopyranoside (9), quercitrin (10), methyl p-digallate (11), methyl m-digallate (12), p-digalloyl acid (13), m-digalloyl acid (14), hyperin (15) and kaempferol-3-O-alpha-L-rhamnoside (16) were isolated by extensive column chromatographic separation. Their structures were elucidated on the basis of chemical and spectroscopic methods. Compound 9 was not reported previously with pyranoside of arabinose at C-3'. Compounds 4 and 9 possessed the activity for PTK inhibition.     

Polyphenolic compounds from the leaves of Koelreuteria paniculata Laxm

From the fresh leaves of Koelreuteria paniculata Laxm (Sapindaceae), four new compounds, named ethyl p-trigallate (1), 3"-O-galloyl-4'-O-galloyl-4-O-galloyl-gallic acid (2), ethyl p-heptagallate (3) and 3"-galloylquercitrin (4), together with 12 known compounds namely catechin (5), galloylepicatechin (6), isorhamnetin (7), kaempferol-3-O-arabinopyranoside (8), quercetin-3'-O- g -D-arabinopyranoside (9), quercitrin (10), methyl p-digallate (11), methyl m-digallate (12), p-digalloyl acid (13), m-digalloyl acid (14), hyperin (15) and kaempferol-3-O- f -L-rhamnoside (16) were isolated by extensive column chromatographic separation. Their structures were elucidated on the basis of chemical and spectroscopic methods. Compound 9 was not reported previously with pyranoside of arabinose at C-3'. Compounds 4 and 9 possessed the activity for PTK inhibition.     

Characterization of myrtle seed (Myrtus communis var. baetica) as a source of lipids,phenolics, and antioxidant activities

This study aimed to characterize the chemical composition and antioxidant activity of the oil and the methanolic extract of Myrtus communis var. baetica seed. The oil yield of myrtle seed was 8.90%, with the amount of neutral lipid, especially triacylglycerol, being the highest, followed by phospholipids and glycolipids. Total lipids and all lipid classes were rich in linoleic acid. The content of total phenols, flavonoids, tannins, and proanthocyanidins of the methanolic extract and the oil from myrtle seed was determined using spectrophotometric methods. Antioxidant activities of the oil and the methanolic extract from myrtle seed were evaluated using 1,1-diphenyl-2-picrylhydrazyl radical scavenging, β-carotene–linoleic acid bleaching, and reducing power and metal chelating activity assays. In all tests, the methanolic extract of myrtle seed showed better antioxidant activity than oil. This investigation could suggest the use of myrtle seed in food, industrial, and biomedical applications for its potential metabolites and antioxidant abilities.     

菝葜多酚类成分抗氧化活性的研究

目的 对菝葜中天然多酚类化合物的抗氧化活性进行研究,探讨多酚类化合物在菝葜药效发挥中的作用机制. 方法 分别采用TEAC法和DPPH法对菝葜醋酸乙酯部位中分离得到的9个天然多酚类化合物单体（SCE 1～9）的抗氧化活性进行测定,并初步分析它们发挥抗氧化作用的构效关系. 结果 化合物SCE 1～9具有很强的抗氧化活性,均能有效地清除ABTS•+和DPPH自由基,其中化合物SCE 1的活性最强,其清除ABTS•+自由基的TEAC值为（3.11±0.04）mmol•L^-1,在浓度50 μmol•L^-1时对DPPH自由基的清除能力为（95.95±0.76）%. 结论 菝葜中天然多酚类化合物可能是菝葜根茎醋酸乙酯提取物发挥治疗作用的物质基础.     

Effect of myrtle fruit syrup on abnormal uterine bleeding: a randomized double-blind,placebo-controlled pilot study

Background

Myrtle (Myrtus communis L.) has been used in the Iranian Traditional Medicine as a treatment for abnormal uterine bleeding-menometrorrhagia. The main aim of this study is to evaluate the effect of myrtle fruit syrup on abnormal uterine bleeding-menometrorrhagia.

Methods

A randomized, double-blind, placebo-controlled pilot study was conducted on 30 women suffering from abnormal uterine bleeding-menometrorrhagia. Treatment comprised of giving 15 ml oral myrtle syrup daily (5 ml three times a day) for 7 days starting from the onset of bleeding. The myrtle syrup along with placebo was repeated for 3 consecutive menstrual periods. Menstrual duration and number of used pads were recorded by the Pictorial Blood loss Assessment Chart at the end of each menstrual period. The quality of life was also evaluated using the menorrhagia questionnaire.

Results

The mean number of bleeding days significantly declined from 10.6 ± 2.7 days to 8.2 ± 1.9 days after 3 months treatment with the syrup (p = 0.01) and consequently the participants in the intervention group used fewer pads after 3 months (16.4 ± 10.7) compared with the number of pads used at the beginning of the treatment (22.7 ± 12.0, p = 0.01). Bleeding days and number of pads used by the participants in the placebo group did not change significantly. Also significant changes of quality of life scores were observed in the intervention group after 3 months compared to the baseline.

Conclusion

Myrtle syrup is introduced as a potential remedy for abnormal uterine bleeding-menometrorrhagia.     

铁皮石斛叶总黄酮泡腾颗粒剂的制备与抗氧化活性研究

目的 获得铁皮石斛叶黄酮提取物泡腾颗粒剂的制作工艺并测定其抗氧化能力。方法 采取L₉(3⁴)正交设计法,以粒度、溶化时间为评价指标,考察乳糖的用量、柠檬酸与碳酸氢钠的配比、PEG6000的用量对泡腾颗粒剂影响,以最佳处方制备泡腾颗粒剂,并采用《中国药典》2015年版方法对其进行质量评价。采用NaNO2比色法测定制剂中总黄酮的含量。采用DPPH法测定制剂的抗氧化能力。结果 最佳处方为乳糖用量40%,柠檬酸与碳酸氢钠的配比1.3:1,PEG6000用量9%。所得制剂符合《中国药典》2015年版相关标准,其总黄酮含量为(1.29±0.08)mg·g^-1,DPPH清除能力的IC₅₀为(3.77±0.10)mg·mL^-1。结论 本论文将铁皮石斛叶黄酮提取物制备成吸收快、生物利用度高、便于运输携带的泡腾颗粒制剂,该制剂黄酮含量丰富,具有较好的抗氧化能力。     

Constituents from leaves of Apocynum venetum L.

An analysis using HPLC–MS revealed that an extract from dried leaves of Apocynum venetum L. contained more than 15 kinds of phenolic constituents. Two malonated flavonol glycosides were further isolated, and their structures were determined to be quercetin 3-O-(6′′-O-malonyl)-β-d-glucoside (1) and quercetin 3-O-(6′′-O-malonyl)-β-d-galactoside (2) by NMR spectroscopic analysis. This is the first report describing the isolation of these malonated flavonol glycosides from A. venetum L. Both glycosides showed strong scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical.     

Antioxidative flavonoids from the leaves ofMorus alba

Nine flavonoids (1-9) were isolated from the leaves of Morus alba (Moraceae). The structures of compounds were determined to be kaempferol-3-O-beta-D-glucopyranoside (astragalin, 1) kaempferol-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (2), quercetin-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-glucopyranoside (4), kaempferol-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (5), quercetin-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (rutin, 6), quercetin-3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (7), quercetin-3,7-di-O-beta-D-glucopyranoside (8) and quercetin (9) on the basis of spectroscopic and chemical studies. Compounds 7 and 9 exhibited significant radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical.     

New cytotoxic benzopyrans from the leaves ofMallotus apelta

Two new benzopyrans 6-[1'-oxo-3'(R)-hydroxy-butyl]-5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran (1) and 6-[1'-oxo-3'(R)-methoxy-butyl]-5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran (2) were isolated from the leaves of Mallotus apelta Muell.-Arg., (Euphorbiaceae). Their chemical structures were elucidated by spectroscopic analyses, especially by 1 D-, 2D-NMR and MS spectra. Compound 1 was found to have strong cytotoxic effect against two human cancer cell lines as human hepatocellular carcinoma (Hep-2, IC50: 0.49 microg/mL) and rhabdosarcoma (RD, IC50: 0.54 microg/mL), while compound 2 showed moderate activity against Hep-2 cell line (IC50, 4.22 microg/mL) by in vitro assay.     

Phenolic compounds on the leaves ofBetula platyphylla var.latifolia

Chemical examination ofBetula platyphylla var. latifolia afforded a novel diarylheptanoid named betulatetraol, together with a phenylpropanoid (3,4′-dihydroxypropiophenone), flavan-3-ol [(+)-catechin] and its glycosides [(+)-catechin 5-O-β-D-glucopyranoside, (+)-catechin 7-O-β-D-glucopyranoside] and two proanthocyanidins (procyanidins B-1 and B-3).     

Lipid peroxidation inhibitory activity of some constituents isolated from the stem bark ofEucalyptus globulus

Twelve compounds with lipid peroxidation inhibitory activity were isolated from the stem bark of E. globulus. Their structures were assigned as a new aromatic monoterpene (1) and eleven known compounds, pinoresinol (2), vomifoliol (3), 3,4,5-trimethoxyphenol 1-O-beta-D-(6'-O-galloyl)glucopyranoside (4), methyl gallate (5), rhamnazin (6), rhamnetin (7), eriodictyol (8), quercetin (9), taxifolin (10), engelitin (11), and catechin (12) on the basis of UV, mass, and NMR spectroscopic analyses. These compounds except vomifoliol significantly inhibited lipid peroxidation in rat liver microsome.     

Tomentodione E,a new sec-pentyl syncarpic acid-based meroterpenoid from the leaves of Rhodomyrtus tomentosa

A new meroterpenoid, tomentodione E (1), along with four known ones (2–5) were isolated from the leaves of Rhodomyrtus tomentosa. Their structures were elucidated based on extensive spectroscopic data as well as computational methods. Compound 1 represents the first example of meroterpenoid possessing a sec-pentyl syncarpic acid motif coupled with a caryophyllene. Compounds 1–4 were evaluated for their in vitro antiviral activity against respiratory syncytial virus (RSV) with cytopathic effect (CPE) reduction assay, and 2 showed potent in vitro anti-RSV effect.     

Anti-proliferative effects of estrogen receptor-modulating compounds isolated from Rheum palmatum

The Rheum palmatum L., a traditional medicine in Korea, was screened for their estrogenic activity in a recombinant yeast system with a human estrogen receptor (ER) expression plasmid and a reporter plasmid used in a previous study. The EC50 values of the n-hexane, dichloromethane, ethyl acetate, n-butanol, and water fractions of the methanolic extract of R. palmatum in the yeast-based estrogenicity assay system were 0.145, 0.093, 0.125, 1.459, 2.853 microg/mL, respectively, with marked estrogenic activity in the dichloromethane fraction. Using an activity-guided fractionation approach, five known anthraquinones, chrysophanol (1), physcion (2), emodin (3), aloe-emodin (4) and rhein (5), were isolated from the dichloromethane fraction. Compound 3 had the highest estrogenic relative potency (RP, 17bestradiol = 1.00) (6.3 x 10(-2)), followed by compound 4 (3.8 x 10(-3)), compound 5 (2.6 x 10(-4)), a compound 1 (2.1 x 10(-4)). Also, compound 3 and fraction 3 (which contained compound 3) of the dichloromethane fraction of R. palmatum showed strong cytotoxicity in both ER-positive (MCF-7) and-negative (MDA-MB-231) breast cancer cell lines.