Differentiation between isomeric acacetin-6-C-(6"-O-malonyl)glucoside and acacetin-8-C-(6"-O-malonyl)glucoside by using low-energy CID mass spectra

Phytochemical analysis and versatile in vitro evaluation of antimicrobial, cytotoxic and enzyme inhibition potential of different extracts of traditionally used Aquilegia pubiflora Wall. Ex Royle

BACKGROUND

Himalayan Columbine (Aquilegia pubiflora Wall. Ex Royle) is a medicinal plant and have been used as traditional treatments for various human diseases including skin burns, jaundice, hepatitis, wound healing, cardiovascular and circulatory diseases. Till now there is no report available on phytochemical investigation of Himalayan Columbine and to the best of our knowledge, through present study we have reported for the first time, the phytochemical analysis and pharmacological potentials of different leaf extracts of Aquilegia pubiflora.

METHODS

Four types of extracts were prepared using solvent of different polarities (Distilled water APDW, Methanol APM, Ethanol APE and Ethyl acetate APEA), and were evaluated to determine the best candidate for potent bioactivity. Phytochemical constituents in prepared extracts were quantified through HPLC analysis. Subsequently, all four types of leaf extracts were then evaluated for their potential bioactivities including antimicrobial, protein kinase inhibition, anti-inflammatory, anti-diabetic, antioxidant, anti-Alzheimer, anti-aging and cytotoxic effect.

RESULTS

HPLC analysis demonstrated the presence of dvitexin, isovitexin, orientin, isoorientin, ferulic acid, sinapic acid and chlorogenic acid in varied proportions in all plant extracts. Antimicrobial studies showed that, K. pneumonia was found to be most susceptible to inhibition zones of 11.2 ± 0.47, 13.9 ± 0.33, 12.7 ± 0.41, and 13.5 ± 0.62 measured at 5 mg/mL for APDW, APM, APE and APEA respectively. A. niger was the most susceptible strain in case of APDW with the highest zone of inhibition 14.3 ± 0.32, 13.2 ± 0.41 in case of APM, 13.7 ± 0.39 for APE while 15.4 ± 0.43 zone of inhibition was recorded in case of APEA at 5 mg/mL. The highest antioxidant activity of 92.6 ± 1.8 μgAAE/mg, 89.2 ± 2.4 μgAAE/mg, 277.5 ± 2.9 μM, 289.9 ± 1.74 μM for TAC, TRP, ABTS and FRAP, respectively, was shown by APE. APM, APE and APEA extracts showed a significant % cell inhibition (above 40%) against HepG2 cells. The highest anti-inflammatory of the samples was shown by APE (52.5 ± 1.1) against sPLA2, (41.2 ± 0.8) against 15-LOX, followed by (38.5 ± 1.5) and (32.4 ± 0.8) against COX-1 and COX-2, respectively.

CONCLUSIONS

Strong antimicrobial, Protein Kinase potency and considerable α-glucosidase, α-amylase, and cytotoxic potential were exhibited by plant samples. Significant anti-Alzheimer, anti-inflammatory, anti-aging, and kinase inhibitory potential of each plant sample thus aware us for further detailed research to determine novel drugs.

Influence of Linkage Stereochemistry and Protecting Groups on Glycosidic Bond Stability of Sodium Cationized Glycosyl Phosphates

Energy-resolved collision-induced dissociation (ER-CID) experiments of sodium cationized glycosyl phosphate complexes, [GP _x +Na]⁺, are performed to elucidate the effects of linkage stereochemistry (α versus β), the geometry of the leaving groups (1,2-cis versus 1,2-trans), and protecting groups (cyclic versus non-cyclic) on the stability of the glycosyl phosphate linkage via survival yield analyses. A four parameter logistic dynamic fitting model is used to determine CID_50% values, which correspond to the level of rf excitation required to produce 50% dissociation of the precursor ion complexes. Present results suggest that dissociation of 1,2-trans [GP _x +Na]⁺ occurs via a McLafferty-type rearrangement that is facilitated by a syn orientation of the leaving groups, whereas dissociation of 1,2-cis [GP_x+Na]⁺ is more energetic as it involves the formation of an oxocarbenium ion intermediate. Thus, the C1-C2 configuration plays a major role in determining the stability/reactivity of glycosyl phosphate stereoisomers. For 1,2-cis anomers, the cyclic protecting groups at the C4 and C6 positions stabilize the glycosidic bond, whereas for 1,2-trans anomers, the cyclic protecting groups at the C4 and C6 positions tend to activate the glycosidic bond. The C3 O-benzyl (3 BnO) substituent is key to determining whether the sugar or phosphate moiety retains the sodium cation upon CID. For 1,2-cis anomers, the 3 BnO substituent weakens the glycosidic bond, whereas for 1,2-trans anomers, the 3 BnO substituent stabilizes the glycosidic bond. The C2 O-benzyl substituent does not significantly impact the glycosidic bond stability regardless of its orientation. Graphical abstract ᅟ.

Aquilegia vulgaris extract protects against the oxidative stress and the mutagenic effects of cadmium in Balb/c mice

Cadmium (Cd) is a non-essential element and is a widespread environmental pollutant. Exposure to cadmium can result in cytotoxic, carcinogenic and mutagenic effects. The aim of the current work was to evaluate the protective effect of Aquilegia vulgaris extract against the oxidative stress and the genotoxicity induced by Cd using the chromosomal aberrations in somatic and germ cells assay and random amplified polymorphism DNA (RAPD-PCR) analysis. Forty male Balb/c mice were divided into four groups including the control group, Cd-treated group and the groups treated with the extract alone or plus Cd. The results indicated that Cd increased serum ALT, AST, urea, LDH, CK, lipid peroxidation in liver tissue accompanied with a significant decrease in GPX and SOD. Cd also increased the number of chromosomal aberrations in bone marrow and spermatocytes including structural and numerical aberrations. Animals treated with the extract alone were comparable to the control regarding all the tested parameters. The extract succeeded in preventing or diminishing the oxidative stress and the clastogenic effects of Cd. It could be concluded that Aquilegia vulgaris extract is a promising protective agent against oxidative stress and genotoxicity during the exposure to Cd.

Metabolic responses of Thellungiella halophila/salsuginea to biotic and abiotic stresses: metabolite profiles and quantitative analyses

The metabolite profiles of the model crucifer Thellungiella salsuginea (salt cress) ecotype Shandong subjected to various biotic and abiotic stresses were analyzed using HPLC-DAD-ESI-MS. Two different cruciferous microbial pathogens, Albugo candida, a biotrophic oomycete, and Leptosphaeria maculans, a necrotrophic fungus, elicited formation of the phytoalexins wasalexins A and B without causing visual damage on inoculated leaves. Analyses of non-polar and polar metabolites led to elucidation of the chemical structures of five metabolites: 4'-O-(E)-sinapoyl-7-methoxyisovitexin-2''-O-beta-D-glucopyranoside, 4'-O-(E)-sinapoylisovitexin-2''-O-beta-D-glucopyranoside, 4-O-beta-D-glucopyranosyl-7-hydroxymatairesinol, 5'-O-beta-D-glucopyranosyldihydroneoascorbigen and 3-O-beta-D-glucopyranosylthiane. 3-O-beta-D-glucopyranosylthiane, an unique metabolite for which we suggest the name glucosalsuginin, is proposed to derive from the glucosinolate glucoberteroin. In addition, the identification of a broad range of polar metabolites identical to those of other crucifers was carried out. Quantification of several metabolites over a period of eight days showed that concentrations of the polar phytoanticipin 4-methoxyglucobrassicin increased substantially in leaves irradiated with UV light (lambda(max) 254 nm) relative to control leaves, but not in leaves subjected to other stresses.

Protective effect of Aquilegia vulgaris (L.) against lead acetate-induced oxidative stress in rats

Oxidative stress has been proposed as a possible mechanism involved in lead toxicity. The current study was carried out to evaluate the antioxidant activity of the ethanol extract of Aquilegia vulgaris (L.) against lead acetate (LA)-induced oxidative stress in male rats. Tested animals were treated orally with A. vulgaris extract (100 ppm) in combination with, before, or after LA treatment (20 ppm). The results indicated that the extract alone did not induce any significant changes in body weight gain, food intake, serum biochemical chemistry or the histological picture of the liver and kidney. However, it increased significantly the level of Glutathione (GSH). On the other hand, LA decreased food intake, body weight gain and induced oxidative stress as indicated by the significant changes in serum biochemical parameters and histological picture of liver and kidney and increased lipid peroxide and reduces GSH levels in liver tissues. The extract succeeded to improve the histological pictures of liver and kidney and the biochemical parameters towards the normal values of the control. Moreover, this improvement was pronounced in the animals treated with the extract after LA intoxication.

New acylated flavone and cyanogenic glycosides from Linum grandiflorum

The first investigation of Linum grandiflorum resulted in the isolation of one new acylated flavone O-diglycoside known as luteolin 7-O-alpha-D-(6'''-E-feruloyl)glucopyranosyl (1 --> 2)-beta-D-glucopyranoside, and one new cyanogenic glycoside known as 2-[(3'-isopropoxy-O-beta-D-glucopyranosyl)oxy]-2-methylbutanenitrile, together with four known flavonoid glycosides, three known cyanogenic glycosides and one alkyl glycoside. The new compounds were structurally elucidated via the extensive 1D, 2D NMR and DIFNOE together with ESI-TOF-CID-MS/MS and HR-MALDI/MS.

Effect of Aquilegia vulgaris (L.) ethyl ether extract on liver antioxidant defense system in rats

INTRODUCTION

The ethyl ether extract from Aquilegia vulgaris (L.) (Ranunculaceae) contains a lot of phenolic acids. Their hydroxyl groups are capable of donating hydrogen atoms at the initial stage of lipid peroxidation (LPO), which inactivates hydroxyperoxides formed from polyunsaturated fatty acids (PUFAs) and leads to breakdown of the propagation chain.

MATERIAL AND METHODS

Rats pretreated with acetaminophen (APAP) (600 mg/kg b.w., p.o.) were given ethyl ether extract (100 mg/kg b.w., p.o.) obtained from A. vulgaris herb. The study parameters measured were microsomal lipid peroxidation, reduced glutathione, and the activity of hepatic antioxidant enzymes and some drug metabolizing enzymes.

RESULTS

The treatment with ethyl ether extract of the herb produced a 87-95% decrease in uninduced and Fe2+/ascorbate-stimulated microsomal lipid peroxidation in the liver of rats receiving APAP. Hepatic glutathione level depleted by APAP increased significantly (by 18%) after the extract treatment. Antioxidant enzyme activity in the liver, inhibited by APAP, was found to increase after administration of the extract: catalase by about 36%, glutathione reductase by 27% and glutathione S-transferase by 29%. Glucose-6-phosphate dehydrogenase, which decreased after APAP administration, increased again by 26% after extract treatment. The extract tested did not affect the activity of DT-diaphorase. The cytochrome P450 content, depleted by APAP, increased as much as by 100% after the treatment. The activities of NADPH-cytochrome P450 reductase, aniline hydroxylase and aminopyrine N-demethylase were not affected.

CONCLUSIONS

The protective effect of the Aquilegia vulgaris extract in APAP-induced liver injury was mediated by its antioxidant activity. The extract did not inhibit the formation of reactive intermediate metabolites of APAP.

New features on the fragmentation and differentiation of C-glycosidic flavone isomers by positive electrospray ionization and triple quadrupole mass spectrometry

Six flavone mono-C-glucosides, four standards (beta-D-glucopyranosyl-(1 --> C-6)- and -(1 --> C-8)- apigenin and luteolin) and two others from lemon juice (beta-D-glucopyranosyl-(1 --> C-6)- and -(1 --> C-8)-diosmetin) have been studied in order to analyze their fragmentation patterns. Initial separation was carried out using high-performance liquid chromatography with diode-array detection (HPLC/DAD) coupled to an electrospray ionization (ESI) interface and a triple quadrupole mass spectrometer. Several systematic differences between collision-induced dissociation tandem mass (CID-MS/MS) spectra of C-6- and C-8-isomers have been found and some general guidelines and two new diagnostic product ions have been proposed for the differentiation of C-6- and C-8-flavonoid glycosides. These results have been successfully applied to the characterization of two flavone C-glycosides found in lemon juice, and mass spectra of a flavone di-C-glycoside detected in lemon juice have been studied and interpreted.

Glucose–sulfate conjugates as a new phase II metabolite formed by aquatic crustaceans

We found that aquatic crustaceans, decapoda; atyidae (Caridina multidentata, Neocaridina denticulate, and Paratya compressa), metabolize pyrene to a new conjugation product. The results of deconjugation treatments indicated that glucose and sulfate combined with 1-hydroxypyrene. Further analysis by LC/ESI-MS/MS showed that the molecular weight of the product was 460 (m/z 459; deprotonated ion), and that it has a glucose-sulfate moiety (m/z 241; fragment ion). These results indicated that the new metabolite was the glucose-sulfate conjugate of 1-hydroxypyrene. The glucose-sulfate conjugate is a phase II product that has not been reported previously from any organism. Several studies have demonstrated that sulfation is an important pathway for metabolism of xenobiotics in aquatic invertebrates. Thus, glucose-sulfate conjugates may add an important signal for excretion or sequestration of xenobiotics for aquatic invertebrates.

Protective effect of Aquilegia vulgaris L. on aflatoxin B(1)-induced hepatic damage in rats

The aim of the study was to investigate the effect of ethanol and ethyl acetate extract obtained from Aquilegia vulgaris L. on microsomal lipid peroxidation, reduced glutathione level and antioxidant enzymes activity in the liver of rats intoxicated with aflatoxin B(1) (AFB(1)). Animals were pretreated with 12 daily p.o. doses of the extracts tested (100mg/kg body weight). Then AFB(1) was administered intraperitoneally at a single dose of 1.5mg/kg b.w. to evoke the liver damage. α-Tocopherol was used as a positive control. Reduced glutathione (GSH) was depleted in aflatoxin-treated rats by 80% in comparison with that in the controls. The extracts restored the GSH concentration up to the basal level. Microsomal lipid peroxidation stimulated by Fe(2+)/ascorbate (assessed by measuring TBARS) was enhanced in AFB(1)-treated rats by 28% as compared to that in the control group. The extracts caused a decrease in TBARS level by 40% and 27%. Only two antioxidant enzymes were affected by AFB(1) administration. The activity of catalase was reduced by 24% and the activity of glutathione-S-transferase (GST) was increased by 33%. The pretreatment with ethyl acetate and ethanol extract reduced the GST activity by 76% and 30%, respectively. No significant changes in the activity of other antioxidant enzymes were observed in rats treated with the extracts and AFB(1). It can be concluded that multiple pretreatment with the extracts obtained from A. vulgaris attenuated aflatoxin B(1)-induced hepatic damage as evidenced by inhibition of lipid peroxidation and preventing reduced glutathione depletion.

Protective effect of Aquilegia vulgaris (L.) on APAP-induced oxidative stress in rats

Rats pretreated with acetaminophen (N-acetyl-p-aminophenol, APAP) (600 mg/kg b.w., p.o.) were administered with ethanol and ethyl acetate extracts as well as with isocytisoside (100 mg/kg b.w., p.o.) obtained from Aquilegia vulgaris (L.) (Ranunculaceae) herb. The substances tested decreased enzymatic, non-enzymatic and uninduced microsomal lipid peroxidation (LPO) in the liver of rats treated with APAP by 18-48%. Activity of the antioxidant enzymes in the liver inhibited by APAP was increased in the majority of groups after administration of the substances tested: catalase (CAT) by 55%, glutathione peroxidase (GPx) by 50%, glutathione reductase (GR) by 35% and glutathione S-transferase (GST) by 60%. Hepatic glutathione level depleted by APAP was only slightly increased by the substances tested. The cytochrome P450 contents, and the activities of NADPH-cytochrome P450 reductase and two monooxygenases were not affected by the extracts and isocytisoside. It can be concluded that the protective ability of the substances tested in APAP-induced liver injury is mediated by amelioration of microsomal lipid peroxidation and restoring antioxidant enzymes activity. Inhibition of enzymes responsible for metabolic activation of APAP is not involved in this process.

Identification and mass spectrometric characterization of glycosylated flavonoids in Triticum durum plants by high-performance liquid chromatography with tandem mass spectrometry

A mass spectrometric method for extensive detection and semi-quantitative determination of flavonoid glycosides in stem and leaves of young Triticum durum plants is presented. About 100 g of sample were lyophilized and ground, and the compounds of interest were then extracted, cleaned-up, and fractionated using high-performance liquid chromatography (HPLC). Tandem mass spectrometry analyses were performed using a quadrupole-linear ion trap instrument with an information-dependent data acquisition (IDA) protocol that looped two experiments, enhanced MS scan and enhanced product ion scan. Various glycoconjugates, which are all derivatives of only four flavones, apigenin, luteolin, chrysoeriol and tricin, were identified and belong to the following categories: 7 monoglycosides, 31 diglycosides, 15 triglycosides and 1 tetraglycoside. Among these some acylated glycosides were found. Tricin derivatives are present exclusively as O-glycosides, while apigenin and luteolin are present always as C-glycosides. Semi-quantitative estimation was performed by using the monoglycoside and diglycoside of quercetin as internal standards.

Antimicrobial activity of isocytisoside and extracts of Aquilegia vulgaris L

AIMS

The aim of this study was to analyse the antimicrobial properties extracts of Aquilegia vulgaris, and their principial flavonoid component and to compare the obtained results with the activity of gentamicin and nystatin.

METHODS AND RESULTS

The ethanol, acetone and isopropanol extracts as well as the subextracts isolated from the methanol extract together with the main flavonoid: 4'-methoxy-5,7-dihydroxyflavone 6-C-glucoside (isocytisoside) were obtained from the leaves with stems of Aquilegia vulgaris L. All the extracts were analysed by TLC to confirm flavonoids and phenolic acids occurrence. The antimicrobial activity was tested by the method of series dilutions against different Gram-positive, Gram-negative bacteria and also fungi. The results have shown that the extracts, subextracts and isocytisoside inhibit growth of all studied micro-organisms, revealing the greatest activity against Gram-positive Staphylococcus aureus, Staph. epidermidis and the mould Aspergillus niger.

CONCLUSIONS

The antimicrobial activity of the tested materials it is possibly related to the content of isocytisoside.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study has determined new activity of A. vulgaris and suggested the necessity of further studies.

PAH biotransformation in terrestrial invertebrates--a new phase II metabolite in isopods and springtails

Soil-living invertebrates are exposed to high concentrations of contaminants accumulating in dead organic matter, such as polycyclic aromatic hydrocarbons (PAHs). The capacity for PAH biotransformation is not equally developed in all invertebrates. In this paper, we compare three species of invertebrates, Porcellio scaber (Isopoda), Eisenia andrei (Lumbricidae) and Folsomia candida (Collembola), for the metabolites formed upon exposure to pyrene. Metabolic products of pyrene biotransformation in extracts from whole animals or isopod hepatopancreas were compared to those found in fish bile (flounder and plaice). An optimized HPLC method was used with fluorescence detection; excitation/emission spectra were compared to reference samples of 1-hydroxypyrene and enzymatically synthesized conjugates. Enzymatic hydrolysis after fractionation was used to demonstrate that the conjugates originated from 1-hydroxypyrene. All three invertebrates were able to oxidize pyrene to 1-hydroxypyrene, however, isopods and collembolans stood out as more efficient metabolizers compared to earthworms. In contrast to fish, none of the invertebrates produced pyrene-1-glucuronide as a phase II conjugate. Both Collembola and Isopoda produced significant amounts of pyrene-1-glucoside, whereas isopods also produced pyrene-1-sulfate. A third, previously unknown, conjugate was found in both isopods and springtails, and was analysed further using electrospray and atmospheric pressure chemical ionisation mass spectrometry. Based on the obtained mass spectra, a new conjugate is proposed: pyrene-1-O-(6"-O-malonyl)glucoside. The use of glucose-malonate as a conjugant in animal phase II biotransformation has not been described before, but is understandable in the microenvironment of soil-living invertebrates. In the earthworm, three other pyrene metabolites were observed, none of which was shared with the arthropods, although two were conjugates of 1-hydroxypyrene. Our study illustrates the great variety of the still unexplored metabolic diversity of invertebrate xenobiotic metabolism.

Electrospray mass spectrometric decomposition of some glucuronic acid-containing flavonoid diglycosides

Mass spectrometric fragmentation patterns of herbacetin 3-O-glucopyranoside-8-O-glucuronopyranoside (1), gossypetin 3-O-glucopyranoside-8-O-glucuronopyranoside (2) and takakin 7-O-glucopyranoside-8-O-glucuronopyranoside (3) were elucidated from mass spectra obtained with electrospray ionisation. The usefulness of the fragmentation patterns observed in the positive and negative mode for structural elucidation of the studied compounds is discussed. The fragmentation of 3 was substantially different from 1 and 2, especially in the negative mode. In order to explain these differences, theoretical calculations were performed.