Quantitative HPLC Analysis of Benzene Derivatives of Melicope Ptelefolia Leaves

A high performance liquid chromatography procedure for the quantitative determination of three marker benzene derivatives, 2,4,6-trihydroxy-3-prenyl acetophenone (tHPA) (1), 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA) (2), and p-O-geranyl coumaric acid (GCA) (3), in the Melicope ptelefolia ethanolic leaf extracts, a medicinal herb obtained from a few locations of the Peninsula Malaysia, was described. The quantitative analysis was performed using high performance liquid chromatography-photodiode array detection on Xterra octadecylsiyl silica (ODS; 3.0?×?150 mm, 3.5 μm) column kept at 32°C, using gradient elution with acetonitrile and water containing 0.1% formic acid at a flow-rate of 1 ml/min with UV detection wavelength at 280 nm. All calibration curves showed good linearity (R² of 0.999 to 1.0000) within the concentrations range of 2.5?×?10^?3 to 0.1 mg/mL. The method was shown to be simple, sensitive, and reliable for qualitative and quantitative analysis of the marker compounds in M. ptelefolia leaf preparations.     

Antioxidant activity and total phenolic content of Agaricus brasiliensis (Agaricus blazei Murril) in two stages of maturity

The antioxidant capability and total phenolic contents of methanolic extracts of Agaricusbrasiliensis in two stages of maturity, young (YB) and mature (MB), were evaluated in this work. Four complementary assays, reducing power, radical scavenging capacity, inhibition of lipid peroxidation and chelating ability for ferrous ions were used to screen the antioxidant properties of extracts. Minor differences in the composition of phenolic compounds were detected, but the extracts showed similar antioxidant activities, except for the chelating ability for ferrous ions, higher in MB than in YB. Our results support the use of both young and mature fruiting bodies of Agaricus blazei as sources of antioxidant compounds.     

Antioxidant and radical-scavenging carbazole alkaloids from the oleoresin of curry leaf (Murraya koenigii Spreng.)

Oleoresin of curry leaves (Murraya koenigii Spreng.), obtained using acetone, was evaluated for its antioxidant activity using a β-carotene–linoleic acid model system along with the other extracts obtained using methanol, water and volatile oil. The oleoresin showed maximum activity of 83.2% at 100 ppm among all other extractives in comparison to a synthetic antioxidant, namely, butylated hydroxy anisole which exhibited 90.2% activity at the same concentration. The methanol and water extracts showed activities of 16.7% and 11.3%, respectively, at the same concentration. The volatile oil showed negligible (<10%) activity at 100 ppm concentration. Therefore, the oleoresin was fractionated on a silica gel column to obtain five compounds. Among the five, two compounds with maximum antioxidant activity were identified by ¹H and ¹³C NMR spectra as mahanimbine and koenigine. Koenigine also showed a high degree of radical-scavenging activity.     

A new type of Brazilian propolis: Prenylated benzophenones in propolis from Amazon and effects against cariogenic bacteria

Ethanol extracts of four propolis samples (E1–E4) from Manaus (Brazilian Amazon) were analysed by HPLC/DAD/ESI–MS/MS and GC/EIMS. The major constituents of E2 and E4 were analysed by NMR (¹H and ¹³C) and ESI/MS/MS. The main constituents of E2 and E4 are polyprenylated benzophenones: 7-epi-nemorosone, 7-epi-clusianone (major E4 constituents), xanthochymol and gambogenone (major E2 constituents), making up a chemical profile so far unreported for Brazilian propolis. Aristhophenone, methyl insigninone, 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone B, and derivatives of dimethyl weddellianone A and B, propolones, and a scrobiculatone derivative, were detected as minor constituents. Triterpenoids (β-amyrins, β-amyrenone, lupeol and lupenone) were ubiquitous and predominant in E1 and E3. The extracts E2 and E4 were highly active against the cariogenic bacteria Streptococcusmitis, Streptococcusmutans and Streptococcussalivarius. E2 was more active than E4, probably due to a higher content of 2-epi-nemorosone, while the latter was richer in di-hydroxylated compounds.     

New phragmalin-type limonoids from Swietenia macrophylla King

The fruit of Swietenia macrophylla is commonly known as “sky fruit”. The fruit, which contains flavonoids and saponins, is processed commercially into a wide range of health foods and healthcare products. The fruit concentrate is used traditionally to improve blood circulation and impart a healthy skin. In this paper, we describe the isolation and structure elucidation of three new phragmalin ortho esters, named swietephragmin H-J (1–3), and a new polyhydroxylated phragmalin, named swietemacrophine (4), from the leaves of S. macrophylla. The structures of the compounds were elucidated by spectroscopic methods, including HRESIMS, ¹H NMR, ¹³C NMR, DEPT, ¹H–¹H COSY, HMQC, HMBC and NOESY spectra. This is the first report of phragmalin ortho esters and a polyhydroxylated phragmalin from this plant.     

Phenolic compounds from the leaves of Cyclocarya paliurus (Batal.) Ijinskaja and their inhibitory activity against PTP1B

Phenolic compounds were separated from the leaves of Cyclocarya paliurus (Batal.) Ijinskaja and their bioactivities were evaluated through an in vitro PTP1B inhibitory assay. Bioassay-guided fractionation of the ethanol extract has resulted in the isolation of a naphthoquinone derivative, (1R, 2R, 4R)-1,2,4-trihydroxy-1,2,3,4-tetrahydro-naphthalene-1-O-β-d-glucopyranoside, named cyclonoside A, and a lactone, (4R, 5S, 6R)-8,9,10-trihydroxy-4-[3′,4′-dihydroxyphenyl]-1,6-dioxaspiro[4,5]decan-2-one, named cyclospirolide, along with 10 known phenolic compounds: quercetin-3-O-α-d-glucuronide, quercetin-3-O-β-d-glucuronide, myricetin-3-O-β-d-glucuronide, 1-caffeoylquinic acid, 3-caffeoylquinic acid, 4-caffeoylquinic acid, 5-caffeoylquinic acid, caffeic acid, 5-hydroxynaphthalene-1, 4-di-O-β-d-glucopyranoside and piceid. The structures of these compounds were established by means of spectroscopic methods including extensive 2D NMR techniques and chemical evidence. Among all the compounds, 1, 2, 4, 5, 10 and 11 showed strong inhibition against PTP1B, with IC₅₀ values ranging from 1.922 ± 0.480 to 10.50 ± 2.67 μg/mL. The results suggested that the extract from this plant could be used as a potential source for functional food ingredient with anti-obesity.     

Commercial extract of the brown seaweed Ascophyllum nodosum enhances phenolic antioxidant content of spinach (Spinacia oleracea L.) which protects Caenorhabditis elegans against oxidative and thermal stress

There is considerable interest to enhance the nutritional quality of fresh produce especially vegetables. The effects of root treatment of spinach with commercial extracts of the brown macro alga, Ascophyllum nodosum (ANE) on antioxidant level of spinach were studied. At the concentration of 1.0 g/L, ANE treatment significantly increased the total phenolics and flavonoids content, total antioxidant activity (as measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging capacity) and Fe²⁺ chelating ability in spinach leaves. The ¹H NMR and LC-MS analyses of spinach extract suggests that the increased antioxidant activity is largely associated with flavonoids. The biological effect of ANE-enhanced polyphenols was tested using the Caenorhabditis elegans nematode model. The extracts from ANE-treated spinach significantly improved the survival of the animals under oxidative stress by 50% and high temperature stress by 61% as compared to the extracts from untreated plants (0% and 38%, respectively). Taken together, the results suggest that ANE stimulate flavonoid synthesis in spinach leaf thus enhancing its nutritional quality. Furthermore, the increased flavonoid content exerts beneficial effects in C. elegans against oxidative and heat stress.     

Studies on the antioxidant potential of flavones of Allium vineale isolated from its water-soluble fraction

The aim of this work was to examine the chemical constituents and antioxidant potential of water-soluble fractions from the commonly consumed vegetable, Allium vineale. The water-soluble fraction, containing phenolic compounds, was extracted with ethyl acetate to obtain flavonoids which were separated and purified by repeated column chromatography over Sephadex LH-20, RP C18 and silica gel. The isolated compounds were identified according to their physicochemical properties and spectral data (UV, HPLC–TOF/MS, ¹H NMR, ¹³C NMR and 2D NMR). Three flavonoids were isolated and identified as chrysoeriol-7-O-[2″-O-E-feruloyl]-β-d-glucoside (1), chrysoeriol (2), and isorhamnetin-3-β-d-glucoside (3). Antioxidant studies of the aqueous extract and three isolated compounds, 1, 2, 3, were undertaken and they were found to have significant antioxidant activity. Antioxidant activities were evaluated for total antioxidant activity by the ferric thiocyanate method, ferric ion (Fe³⁺) reducing antioxidant power assay (FRAP), ferrous ion (Fe²⁺) metal chelating activity, and DPPH free radical-scavenging activity. The water-soluble ethyl acetate and methanol extraction methods were also compared using HPLC–TOF/MS.     

Two unusual minor 18,19-seco-ursane glycosides from leaves of Ilex cornuta

The leaves of Ilex cornuta is traditionally used as a functional tea in China. Two new minor 18,19-seco-ursane glycosides, named cornutaoside A (1) and B (2), were isolated from leaves of I. cornuta, along with two known compounds (3 and 4). Their structures were elucidated as (3β,12β)-3-[β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-12,21-dihydroxy-19-oxo-18,19-secours-13(18)-en-28-oic acid (1) and (3β,12β)-3-[β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-12,19,21-trihydroxy-18,19-secours-13(18)-en-28-oic acid (2), by chemical methods, 1D and 2D NMR experiments, and by comparison with known analogues. This is the first report of E-seco triterpenoids and diterpene skeletons (4) from this plant. In a preliminary cytotoxic test against U937, L1210, and B16 cell lines, 1 and 2 had no significant activities as compared to controls, with concentrations up to 443.61 and 346.25 μM/plate, for 1 and 2, respectively.     

Potent Antidiabetic Activity and Metabolite Profiling of Melicope Lunu‐ankenda Leaves

Diabetes mellitus is normally characterized by chronic hyperglycemia associated with disturbances in the fat, carbohydrate, and protein metabolism. There is an increasing trend of using natural products instead of synthetic agents as alternative therapy for disorders due to their fewer side effects. In this study, antidiabetic and antioxidant activities of different Melicope lunu‐ankenda (ML) ethanolic extracts were evaluated using inhibition of α‐glucosidase and 2,2‐diphenyl‐l‐picrylhydrazyl (DPPH) radicals scavenging activity, respectively; whereas, proton nuclear magnetic resonance (¹H NMR) and ultra‐high performance liquid chromatography‐tandem mass spectrometric (UHPLC‐MS/MS) techniques were used for metabolite profiling of ML leaf extracts at different concentrations of ethanol and water. Sixty percent of ethanolic ML extract showed highest inhibitory effect against α‐glucosidase enzyme (IC₅₀ of 37 μg/mL) and DPPH scavenging activity (IC₅₀ of 48 μg/mL). Antidiabetic effect of ML extracts was also evaluated in vivo and it was found that the high doses (400 mg/Kg BW) of ML extract exhibited high suppression in fasting blood glucose level by 62.75%. The metabolites responsible for variation among ML samples with variable ethanolic levels have been evaluated successfully using ¹H‐NMR–based metabolomics. The principal component analysis (PCA) and partial least squares(PLS) analysis scores depicted clear and distinct separations into 4 clusters representing the 4 ethanolic concentrations by PC1 and PC2, with an eigenvalue of 69.9%. Various ¹H‐NMR chemical shifts related to the metabolites responsible for sample difference were also ascribed. The main bioactive compounds identified attributing toward the separation included: isorhamnetin, skimmianine, scopoletin, and melicarpinone. Hence, ML may be used as promising medicinal plant for the development of new functional foods, new generation antidiabetic drugs, as a single entity phytomedicine or in combinational therapy.     

Activity-guided isolation and identification of free radical-scavenging components from an aqueous extract of Coleus aromaticus

An activity-directed fractionation and purification process was used to identify the DPPH (l,l-diphenyl-2-picrylhydrazyl) free radical-scavenging components of Coleus aromaticus Benth. Fresh leaves of C. aromaticus were extracted with water and then separated into hexane, ethyl acetate, and water fractions. Among these, only the ethyl acetate phase showed strong DPPH radical-scavenging activity in vitro, when compared with water and hexane phases. The ethyl acetate fraction was then subjected to separation and purification using Sephadex LH-20 chromatography. Three compounds showing strong DPPH radical-scavenging activity were shown, by spectral methods (¹H NMR, ¹³C NMR, and MS) and by comparison with literature values, to be rosmarinic acid, chlorogenic acid and caffeic acid. In addition, HPLC identification and quantification of isolated compounds were also performed. Rosmarinic acid was found as a major component and principally responsible for the radical-scavenging activity of C. aromaticus.     

Antioxidant activity and genotoxic effect on HeLa cells of phenolic compounds from infusions of Quercus resinosa leaves

Water infusions of mature and fresh Quercus resinosa leaves were evaluated for antioxidant activity and genotoxic effects on HeLa cells. Native Mexicans used to drink Q. resinosa leaves tea as a refreshing beverage. The air dried leaves were pulverised and boiled in water, then their phenolic content and condensed tannins were determined. The chromatographic profile of 15 phenolic components in Quercus leaves infusions was also determined by HPLC. In vitro analysis of antioxidant capacity of leaves infusion extracts were performed by the DPPH method and the deoxyribose assay. The genotoxicity of Q. resinosa leaves extracts was evaluated on HeLa cells as well as its underlying mechanism by the single-cell electrophoresis assay (comet assay). Results show that fresh leaves infusions increase the oxidative process and other damage to DNA in transformed human cells. Fresh leaves from Q. resinosa may serve as a potential source of phenolics with anticancer activity.     

Caffeoylquinic acids from leaves of Etlingera species (Zingiberaceae)

3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid (chlorogenic acid), and 5-O-caffeoylquinic acid methyl ester, as elucidated by ¹H and ¹³C NMR, were isolated from leaves of Etlingera elatior. This is the first report of caffeoylquinic acids (CQA) including chlorogenic acid (CGA) in Zingiberaceae. Leaves of Etlingera species were rich in total phenols and CQA, and non-cytotoxic to normal human liver and African green monkey kidney cells. Content of CQA of E. elatior, Etlingera fulgens, and Etlingera rubrostriata leaves was significantly higher than leaves of Ipomoea batatas, and comparable to flowers of Lonicera japonica. CGA found only in leaves of E. elatior and E. fulgens was significantly higher in content than flowers of L. japonica, the commercial source.     

Habitat differentiation and degradation characterization of Cinnamomi Cortex by 1H NMR spectroscopy coupled with multivariate statistical analysis

In this study, habitat differentiation and degradation characterization of Cinnamomi Cortex (CC) were carried out using ¹H NMR spectroscopy coupled with multivariate statistical analysis. Twenty-one components were plausibly identified in ¹H NMR spectrum of CC, among which fatty acid, β-glucose, cinnamaldehyde and other seven compounds were screened out as reasonable chemical markers in orthogonal partial least squares-discriminant analysis (OPLS-DA), being responsible for the habitat discrimination of CC from Guangdong and Guangxi provinces of China. The results of ¹H NMR spectroscopy combined with principal component analysis (PCA) revealed that the contents of coumarin and carbohydrates changed mildly during two week-storage, while the degradation of cinnamaldehyde along with some fatty acids was crucial. The degradated products of cinnamaldehyde were supposed as cinnamic acid and styrene, the latter of which is a potential neurotoxic and hepatotoxic compound. The results of radical scavenging assays suggested that degradation could down-regulate anti-oxidation performance of CC. Thus, the efficacy and safety of CC extract after long time storage deserve attention. Above all, ¹H NMR spectroscopy can be used as a reliable tool to assess the quality of medicinal herbs as well as herbal dietary supplements.     

Metabolic profiling and aquaculture differentiation of gilthead sea bream by H NMR metabonomics

This work describes a metabolic profiling study of gilthead sea bream, from three different aquaculture systems, using ¹H NMR and chemometrics. A total of 54 samples under two different storage regimens were analysed. The assignment of all major NMR signals of the perchloric extracts was performed. A comprehensive multivariate data analysis proved able to distinguish the fish metabolism amongst the different aquaculture systems and to determine whether a fish was stored or not. The state of energy metabolism of inosine proved a robust biomarker for evaluating storage time. A new multivariate classification tool, iECVA, revealed several metabolites which are important biomarkers for characterising the three different aquaculture systems: glycogen (stress indicator), histidine, alanine and especially glycine for long storage times and mainly betaine for fresh samples. The findings represent a step forward in understanding how in vivo and postmortem processes affect the total quality of the final product.     

Biochemical monitoring of black raspberry (Rubus coreanus Miquel) fruits according to maturation stage by H NMR using multiple solvent systems

Nuclear magnetic resonance (NMR) techniques coupled with multivariate data analysis were used to conduct monitoring of biochemical changes of black raspberry fruits at different stages of maturation and under various extraction and NMR dissolution solvent conditions: extraction with 50% methanol and D₂O as an NMR dissolution solvent, extraction with 50% methanol and 50% methanol-d₄ as an NMR dissolution solvent, and extraction with 100% ethyl acetate and 100% methanol-d₄ as an NMR dissolution solvent. Partial least-squares discriminant analysis reliably distinguished black raspberry fruits according to the maturation stage, whereby the relative levels of various compounds such as amino acids, organic acids, sugars and phenolic compounds were compared using analysis of variance. Sucrose and most of the amino acids, and organic acids decreased, whereas fructose, glucose, and cyanidins increased in relative concentration according to maturation of black raspberry fruits. The total number and kinds of assigned compounds of the three solvent systems were also compared. This research demonstrates that the metabolic profile of black raspberry fruits changes during maturation, and provides objective criteria for determining the stage of black raspberry fruit maturation via a ¹H NMR-based metabolomics technique using multiple solvent systems.     

Chemometric Analysis of <Superscript>1</Superscript>H NMR Fingerprints of <Emphasis Type="Italic">Coffea arabica</Emphasis> Green Bean Extracts Cultivated under Different Planting Densities

High planting density has been used to increase coffee production but there are few studies related to the variations it provokes in metabolite compositions. The use of ¹H NMR data associated with chemometric techniques allows the determination of metabolic fingerprints and verification of metabolic changes when coffee is subjected to high planting densities. The aim of this work is to investigate ¹H NMR spectral data of green bean extracts of Coffea arabica cv. IAPAR 59 grown in a square pattern at two planting densities, 6000 and 10,000 plants ha^?1. Thirty extracts were obtained using a simplex centroid design with four solvents (ethanol, acetone, dichloromethane, and hexane). The lyophilized extracts were dissolved in DMSO-d₆ to obtain the ¹H NMR spectra. The spectral data were analyzed with principal component (PCA) and cluster analyses (CA). Significant differences between ethanolic and non-ethanolic extracts were found by PCA. Only the ethanolic mean spectrum showed characteristic chemical shifts of sugars and trigonelline. Acetone extracts were separated by cluster analysis.     

Volatile compounds of leaves and fruits of Mangifera indica var. coquinho (Anacardiaceae) obtained using solid phase microextraction and hydrodistillation

Volatile compounds present on fruits and leaves of Mangifera indica var. coquinho were investigated by headspace solid phase microextraction (HS-SPME) and hydrodistillation (HD). Conventional techniques, such as hydrodistillation, may impart chemical changes to the original oil composition being also time-consuming. On the other hand, HS-SPME provides solvent-less extractions, shorter extraction times and may supply complementary information about the composition of the compounds. The HS-SPME technique was previously evaluated by the comparative study among the fibres: commercial PDMS, NiTi-ZrO₂ and NiTi-ZrO₂-PDMS. The fibre NiTi-ZrO₂-PDMS showed better sensitivity and precision and was used on the extraction of components. The influence of several parameters like the time and temperature of extraction and desorption time were examined to obtain better efficiency. Fruits and leaves were analysed in mature and immature stages. The profiles corresponding to the volatile compounds detected by both techniques are discussed.     

Lentinus edodes heterogalactan: Antinociceptive and anti-inflammatory effects

Cold aqueous extraction of basidiocarps (fruiting bodies) of the edible mushroom Lentinus edodes (shiitake) gave rise to a heteropolysaccharide, whose chemical structure, antinociceptive and anti-inflammatory properties were determined. Its chemical structure was based on monosaccharide composition, methylation analysis, and NMR spectroscopy (¹H, ¹³C, HSQC, HSQC-TOCSY, HSQC-NOESY, and coupled HMQC). It was found to be a fucomannogalactan with a main chain of (1 → 6)-linked α-d-galactopyranosyl units, partially substituted at O-2 by single-unit β-d-Manp or α-l-Fucp side chains. The polysaccharide produced a marked and dose-related effect when assessed against acetic acid-induced visceral nociception. Prevention of peritoneal capillary permeability and leukocyte infiltration caused by the acetic acid was similar in potency and effectiveness.