Glycoside Composition Research Articles

Preference, performance, and chemical defense in an endangered butterfly using novel and ancestral host plants

Adoption of novel host plants by herbivorous insects can require new adaptations and may entail loss of adaptation to ancestral hosts. We examined relationships between an endangered subspecies of the butterfly Euphydryas editha (Taylor’s checkerspot) and three host plant species. Two of the hosts (Castilleja hispida, Castilleja levisecta) were used ancestrally while the other, Plantago lanceolata, is exotic and was adopted more recently. We measured oviposition preference, neonate preference, larval growth, and secondary chemical uptake on all three hosts. Adult females readily laid eggs on all hosts but favored Plantago and tended to avoid C. levisecta. Oviposition preference changed over time. Neonates had no preference among host species, but consistently chose bracts over leaves within both Castilleja species. Larvae developed successfully on all species and grew to similar size on all of them unless they ate only Castilleja leaves (rather than bracts) which limited their growth. Diet strongly influenced secondary chemical uptake by larvae. Larvae that ate Plantago or C. hispida leaves contained the highest concentrations of iridoid glycosides, and iridoid glycoside composition varied with host species and tissue type. Despite having largely switched to a novel exotic host and generally performing better on it, this population has retained breadth in preference and ability to use other hosts.

Glycoside Residues on Platelet's Surface Regulate Platelet Function, Apoptosis and Binding of Coagulation Complexes in Patients with Immune Thrombocytopaenia

Introduction: Platelet surface glycoproteins (GPs) are highly glycosylated and are key elements for platelet function since most of them constitute receptors for adhesion ligands. However, exact role of their glycan composition is not clear. Under normal conditions, platelets contain sialic acid in the carbohydrate side chains of their GPs, and it has been described that alterations in the degree of their sialinization can affect the clearance of platelets. This mechanism has been proposed as involved in etiopathogenesis of immune thrombocytopaenia (ITP), mainly in those patients who do not respond to treatments. Thus, after the loss of sialic acid, there would be a greater exposure of galactose and of N-acetyl-glucosamine residues on the surface of circulating platelets to hepatic Ashwell-Morell receptors, which could induce their phagocytosis and platelet clearance. On the other hand, procoagulant platelets, defined as the platelet subpopulation that binds functional prothrombinase, exposed on their surface increased levels of P-selectin and GPIb, two glycan rich GPs. So, it is tempting to speculate that changes in glycan residues on platelet surface may induce changes in their function. Aim: We aimed to assess in ITP patients whether changes in platelet glycosylation, mainly the loss of sialic acid, may condition platelet function, apoptosis and binding of prothrombinase complex. Methods: This is an observational, prospective and transversal study approved by Ethics Committee from La Paz University Hospital. One hundred and eight patients with chronic primary ITP (68 with a platelet count ≥30x103 platelets/µL and 40 with a platelet count <30x103 platelets/µL) and 132 healthy controls were included after signing the informed consent. Platelet activation markers were determined in platelet rich plasma; whereas platelet glycosylation, binding of prothrombinase, annexin V and caspase's activities were assayed in washed platelets. Samples were analyzed by flow cytometry. Table 1 shows lectins tested and their sugar-binding specificity. Data were analyzed with GraphPad Prism 6.0 software. Results: Platelets from ITP patients with a platelet count <30x103/µL exposed less sialic acid in correspondence to an enhanced binding of lectins to non-sialylated residues. Moreover, levels of α1,6-Fucose, a glycan residue which could directly regulate antibody-dependent cellular cytotoxicity, and of α-Mannose, which could be recognized by the mannose binding lectin and activate complement pathway, were increased in platelets from these ITP patients. In accordance, sialic acid loss and consequent platelet surface exposure of other glycoside residues were inversely related to platelet count and ability to be activated (Table 1). These differences in glycosylation observed in ITP patients with a platelet count <30x103/µL were accompanied by a less ability of platelets to be activated (Figure 1), an increased exposure of phosphatidylserine and higher caspase activites (Figure 2). Moreover, increased exposure of phosphatidylserine and of N-acetyl-glucosamine residues (measured through the binding of WGA) enhanced binding of prothrombinase complex (Figure 3). Conclusion: Changes in glycoside composition of GPs on platelet's surface impaired their functional capacity, increases their apoptosis and modifies conditions for the binding of coagulation proteins. These modifications in platelet's glycoside residues seem to be related to severity of ITP. This work was supported by grants from FIS-FONDOS FEDER (PI19/00772) and and Platelet Disorder Support Association. EMM holds a predoctoral fellowship from Fundación Española de Trombosis y Hemostasia (FETH-SETH). Disclosures Butta: Grifols: Research Funding; Novartis: Speakers Bureau; ROCHE: Research Funding, Speakers Bureau; Pfizer: Speakers Bureau; SOBI: Speakers Bureau; Takeda: Research Funding, Speakers Bureau; NovoNordisk: Speakers Bureau. Alvarez Román:Grifols: Research Funding; Bayer: Consultancy; Novartis: Speakers Bureau; Roche: Speakers Bureau; Pfizer,: Research Funding, Speakers Bureau; SOBI,: Consultancy, Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; NovoNordisk,: Research Funding, Speakers Bureau. Martín:SOBI: Research Funding; Pfizer: Research Funding, Speakers Bureau; Roche: Speakers Bureau; Novartis: Speakers Bureau; NovoNordisk: Speakers Bureau. Rivas Pollmar:Novartis: Speakers Bureau; Roche: Speakers Bureau; Pfizer: Speakers Bureau. Justo Sanz:Takeda: Current Employment. García Barcenilla:NovoNordisk: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Pfizer,: Speakers Bureau; Roche: Speakers Bureau; Bayer: Speakers Bureau; Novartis: Speakers Bureau. Canales:Celgene: Honoraria; Janssen: Speakers Bureau; Novartis: Honoraria; Roche: Honoraria; Gilead: Honoraria; Sandoz: Honoraria; iQone: Honoraria; Takeda: Speakers Bureau; Sandoz: Speakers Bureau; Roche: Speakers Bureau; Janssen: Speakers Bureau; Sandoz: Honoraria; Roche: Honoraria; Takeda: Speakers Bureau; Novartis: Honoraria; Sandoz: Speakers Bureau; Karyopharm: Honoraria; Roche: Speakers Bureau; Janssen: Honoraria; Karyopharm: Honoraria; Janssen: Honoraria. Jimenez-Yuste:F. Hoffman-La Roche Ltd, Novo Nordisk, Takeda, Sobi, Pfizer, Grifols, Octapharma, CSL Behring, Bayer: Honoraria; F. Hoffman-La Roche Ltd, Novo Nordisk, Takeda, Sobi, Pfizer: Consultancy; Grifols, Novo Nordisk, Takeda, Sobi, Pfizer: Research Funding.

Polyphenol oxidase dominates the conversions of flavonol glycosides in tea leaves

Flavonol glycosides are associated with astringency and bitterness of teas. To clarify the dominant enzymatic reaction of flavonol glycosides in tea leaves, the catalytic effects of polyphenol oxidase (PPO), peroxidase (POD) and β-glucosidase were studied, with the maintaining rates of total flavonol glycosides (TFG) being 73.0%, 99.8% and 94.3%. PPO was selected for further investigations, including the effects of pH value (3.5 ~ 6.5), temperature (25 °C ~ 55 °C) and dosage (39 ~ 72 U/mL PPO and 36 U/mL PPO, 3 ~ 36 U/mL POD). The oxidation of flavonol glycosides were intensified at pH 6.5, with 51.8% and 15.4% of TFG maintained after PPO and PPO + POD treatments, suggesting an enhancement from POD. The sensitivity ranking to PPO was: myricetin glycosides > quercetin glycosides > kaempferol glycosides. The inhibitor treatment testified the leading role of PPO in catalyzing flavonol glycosides in tea leaves. Sugar moiety enhanced the docking affinity of flavonol glycosides for PPO. PPO shows the potential of modifying flavonol glycoside composition.

Phenolics profiling by HPLC-DAD-ESI-MSn aided by principal component analysis to classify Rabbiteye and Highbush blueberries

Although blueberries are widely studied, little information exists on their composition and content of flavonol glycosides. Most studies identify only a few flavonols in blueberries due to separation and identification issues. In the present study, we identified 44 flavonols and chlorogenic acid in 30 samples of Highbush and Rabbiteye blueberry, using HPLC-DAD-ESI-MSn. Highbush group fruits presented mainly quercetin-3-galactoside in their composition, while Rabbiteye group fruits exhibited higher levels of quercetin-3-rhamnoside and quercetin-3-glucuronide. Among the identified flavonols, 8 acylates (acetyl and hydroxymethylglutaroyl) were found, of which quercetin-3-O-[4″-(3-hydroxy-3-methylglutaroyl)]-α-rhamnoside was found for the first time in blueberries. This compound is exclusive to the cultivars Florida and Powderblue, where it is present in high quantities. Glucuronides of syringetin and laricitrin, and rhamnosyl-galactosides of myricetin, quercetin and isorhamnetin were also found for the first time in blueberries. The Principal Component Analysis showed that blueberry groups can be distinguished based on their phenolic compound profile.

FEATURES OF THE COMPOSITION OF FLAVONOIDS IN THE CROWNED SAW-WORT (SERRATULA CORONATA L.S.L.) SIBERIA AND THE FAR EAST OF RUSSIA

One of the common plants in Siberia and the Far East of Russia, but little studied, is the crowned saw-wort (Serratula coronata L.s.l.) of the aster family (Asteraceae). The value of this plant is determined by its high content of phytoecdysteroids and flavonoids. From the aerial part (leaves, stems) of S. coronata L.s.l., growing in Siberia (Altai Region), by liquid extraction methods (70% ethanol) and preparative column chromatography on silica gel in the gradient elution mode with a mixture of solvents (carbon tetrachloride and ethyl alcohol), 2 flavonoids were isolated: quercetin-4'-O-β-D-glucopyranoside, luteolin-4'-O-β-D-glucopyranoside. Identification of the isolated compounds was carried out by UV-, NMR-13C-, 1H, 13C-HMBC-spectroscopy and electrospray mass spectrometry. The reverse-phase high-performance liquid chromatography (RP-HPLC) method was the first to investigate the qualitative composition and quantitative content of individual flavonoids in S. coronata L.s.l. plants growing in Altai and in the Primorsky region of the Russian Federation. The composition of flavonoid glycosides and the distribution of their aglycones in Siberian and Far Eastern plants differ and this can be considered a chemotaxonomic trait of the species S. coronata L.s.l. The spectrophotometry method was used to determine the sum of flavonoids in the aerial organs of crowned saw-wort growing in Altai and Primorsky region. The content of flavonoids in the leaves of the plant (6.7–8.3%) exceeds their content in the stems (0.5–0.9%). Crowned saw-wort sickle is a potential source of biologically active compounds of this class.

Dietary galactosyl and mannosyl carbohydrates: In-vitro assessment of prebiotic effects

The prebiotic activities of hydrolyzed guar gum (GMOS, <1 kDa; GMPS, 1–10 kDa), manno-oligosaccharide (MOS, <1 kDa), and galacto-oligosaccharide (GOS, <1 kDa) were evaluated by in vitro fermentation. The tested carbohydrates showed selective prebiotic effects on bacterial growth, short-chain fatty acid (SCFA)-production, and substrate consumption. GOS and GMOS markedly promoted the growth of bifidobacteria and Clostridium butyricum, respectively, whereas MOS showed the strongest butyrogenic effect. Moreover, SCFA production in the hydrolyzed guar gum groups was closely related to the varied molecular weight (Mw) of the hydrolysate. During in vitro fermentation with human fecal inocula, GMOS gave the highest yields of lactate, propionate, and butyrate after 48 h fermentation. Combined application of MOS and C. butyricum increased the abundance of Clostridiaceae_1. Overall, our results indicate that galactosyl and mannosyl carbohydrates have individualized prebiotic effects which are associated with their chemical structures including their glycoside composition and Mw.

Safety and Fertility Potential of Kenyan Grewia tenax (Mukawa Wa Guba) Root Extract Secondary Metabolites

Aim: To screen Kenyan Grewia tenax root extract phytochemicals and correlate the attribute fertility enhancing effects and safety in female albino rats.&#x0D; Study Design: An experimental study design was used.&#x0D; Place and Duration of Study: The phytochemical studies were done at Jomo Kenyatta University of Agriculture and Technology (JKUAT), Department of Botany Laboratory, while acute oral toxicity studies were done at the Department of Veterinary Anatomy and Physiology, University of Nairobi (UON) animal house. The study was done during the month of March to June 2019.&#x0D; Methodology: Grewia tenax was harvested with the help of a plant taxonomist. The roots were chopped into small pieces and dried under shade for three weeks. They were then ground into powder. Organic extracts were prepared by sequential extraction (petroleum ether, dichloromethane (DCM), ethyl acetate and methanol), by use of cold maceration. Aqueous extracts were obtained by hot maceration. Phytochemical screening of extracts was done by standard phytochemical procedures. A total of 12 female albino rats were used in acute oral toxicity studies as per OECD 423 guidelines.&#x0D; Results: Methanol extract had the highest composition of phytochemicals, i.e. alkaloids, flavonoids, saponins, sterols, terpenes and cardiac glycosides. Aqueous and DCM extracts showed presence of alkaloids, saponins and cardiac glycosides, while petroleum ether and ethyl acetate extracts showed presence of alkaloids and cardiac glycosides. Steroids and tannins were absent in all extracts. Flavonoids, alkaloids and terpenes are fertility enhancing compounds due to their antioxidant and radical scavenging properties. Flavonoids, alkaloids and glycosides improve fertility by inducing ovarian steroidogenesis and folliculogenesis. In the acute oral toxicity study, there were no adverse effects at 5000 mg/kg extract administration.&#x0D; Conclusion: Kenyan Grewia tenax root extract has phytochemicals postulated to enhance fertility and is orally safe. These findings may require further verification using in vivo studies.

Simultaneous determination of steviol glycosides in stevia by high performance liquid chromatography

A method for determination of steviol glucosides in stevia using high performance liquid chromatography was developed and validated. The compounds were extracted from the matrices with methanol for 60 minutes, cleaned by Oasis HLB column and then determined by HPLC using C18 column (250 mm x 4.6 mm x 5 &amp;micro;m) and PDA detector. The calibration curves were linear in range of 1 to 100 &amp;mu;g/mL; the RSD was of 1.39 &amp;shy; 2.85%; and the recovery was of 93 &amp;shy; 105%. The method was applied to analyze 09 stevia samples collected from markets in Hanoi (including dry stevia rebaudiana, stevia powder). The results showed that composition of steviol glycosides differs from sample to sample. Besides, stevioside and rebaudioside A are the most abundant steviol glycosides in the samples.

Качественный и количественный анализ на содержание фенольных соединений и их производных в корневище Panax vietnamensis Ha et Grushv.

Since ancient times, it is known that all types of ginseng were widely used in Eastern folk medicine as a cure for many diseases. All species of the genus Panax, including Panax vietnamensis, contain saponins, but the phenolic composition has not been studied to date. Vietnamese ginseng is characterized by a unique composition of triterpene glycosides, among which the glycosylated derivatives of the rare triterpene aglycone, okothylol, are predominant. It is the only evergreen among ginsengs. As you know, a single plant can have different types of biological activity due to the content of different groups of biologically active compounds with a wide range of physicochemical properties and causing different pharmacological effects. Obviously, phenolic compounds along with other secondary metabolites in Panax vietnamensis have a phytotherapeutic effect on the human body. The purpose of this work is to expand the knowledge of the scientific community about the synthesized compounds, in particular about phenolic compounds that accumulate in the rhizomes of Panax vietnamensis. In this paper, the results of a study on the qualitative (method HPLC-DMD-MS) and quantitative content of phenolic compounds (Folin-Cicalteu method) of the roots of Panax vietnamensis were presented for the first time. These results can be very interesting for scientists involved in the synthesis of secondary metabolites, growing callus and suspension cell cultures in vitro ginseng and other ginseng species, as well as for pharmaceutical and cosmetic companies producing various consumer products for the population based on Vietnamese ginseng. This work will expand the scientific community’s knowledge of secondary metabolites synthesized by the rhizome Panax vietnamensis Ha et Grushv.

Simultaneous determination of steviol glycosides in food from stevia by liquid chromatography tandem mass spectrometry (LC-MS/MS)

The objective of this study is to develop a method for determination of steviol glycosides in food&amp;nbsp;using liquid chromatography mass tandem spectrometry. The compounds were extracted from&amp;nbsp;the matrices with methanol at 40&amp;deg;C within 60 minutes, and then determined by LC-MS/MS using&amp;nbsp;C18 column (100 mm x 2.1 mm x 3.5 &amp;micro;m), the MS/MS detector with negative ESI mode. The&amp;nbsp;calibration curves were linear in the range of 0.1 to 20 &amp;mu;g/mL; the RSD was of 1.74 &amp;ndash; 5.01%; and&amp;nbsp;the recovery was in range of 90 &amp;ndash; 105%. The method was applied to analyze 20 food samples&amp;nbsp;collected from markets in Hanoi (including dry stevia rebaudiana, stevia powder, stevia tea and soft drinks). The results showed that the composition of steviol glycosides was different from sample to&amp;nbsp;sample. The most abundant steviol glycosides were stevioside and rebaudioside A.

Effects of β-glucosidase and α-rhamnosidase on the Contents of Flavonoids, Ginkgolides, and Aroma Components in Ginkgo Tea Drink.

Ginkgo tea is a kind of health food produced from Ginkgo biloba leaves. The market of Ginkgo tea encountered many difficulties because of its bad palatability and vague function statement. In this study, two kinds of glycosidase were used to improve the flavor of Ginkgo tea, and three kinds of bioactivities were selected to investigate the health care function of the tea infusion. The aroma components extracted by headspace absorb (HSA) method during the making of Ginkgo tea were analyzed by GC-MS. The flavonoids and ginkgolides released into the tea infusion were studied by HPLC. A combination of β-glucosidase (β-G) and α-rhamnosidase (α-R) was applied during the making of the tea. The contents of characteristic aroma components and the release of total flavonoids and ginkgolides were increased significantly by adding β-G and α-R. The composition of flavone glycosides was changed greatly. The free radical scavenging, inhibition of inflammatory cell activation, and tumor cytotoxicity activities of the tea were demonstrably improved. According to the release of active components, Ginkgo tea can be brewed repeatedly for at least three times. The enzymes used here show potential application prospects in the making of Ginkgo tea or tea drink to get higher contents of flavonoids, ginkgolides, and aroma components.

Влияние повышенных концентраций ионов меди на ростовые характеристики и синтез стероидных гликозидов в суспензионной культуре клеток Tribulus terrestris L.

In order to optimize the productivity of plant cell cultures for pharmacologically valuable compounds(steroidal glycosides), the effect of the elevated concentrations copper ions on growth and biosynthetic characteristics of the suspension culture of Tribulus terrestris L. has been studied. It was shown that the increase in the content of copper ions in nutrient medium by 5-100 times (up to 10 uM) did not practically affect growth characteristics of the cell culture; however, high concentrations (5 and 10 uM) caused a significant (below 50%) decrease in the cell viability. It was proved by UPLC ESI MS that the T. terrestris biomass contains a furostanol glycoside, terrestrinin B, and its 25(R)-stereoisomer. An increase in the concentration of copper ions in the medium provided a significant (up to 3 times) increase in the content of furostanol glycosides in the first cultivation cycle, and this compound was maintained in the next 5-7 cultivation cycles, although its content was 1.5-2 times lower. On the contrary, changes in the hormonal status of the medium (removal of α-NAA) could result in changes in the composition of furostanol glycosides (disappearance or a drastic decrease in the content of terrestrozin N derivatives, the presence of which in this plant cell culture was shown previously). It may be concluded that heavy metals (copper ions) can intensify the formation of steroidal glycosides in T. terrestris cell culture, whereas growth regulators (for example, auxins) can change their qualitative composition. copper ions, steroidal glycosides, plant suspension cell culture, Tribulus terrestris The work was financially supported by the Russian Science Foundation (№ 16-14-00126).

Natural sweeteners: health benefits of stevia

Stevia rebaudiana (Bertoni), a perennial shrub, is the sweetest plant belonging to the Asteraceae family. Stevia leaves are an excellent source of diterpene glycosides stevioside, rebaudioside A-F, dulcoside, and steviolbioside, which are responsible for sweetness and have been utilized commercially for sugar substitution in foods, beverages, and medicines. To the best of our knowledge, a large number of studies have been carried out on composition, health implications, and safety of steviol glycosides. However, commercial production of stevia-incorporated food products needs further research in order to meet the huge global demand. Stevia-incorporated products possess better sweetening potency and maximum consumer acceptability, when compared with other sugar substitutes. Hence, the current research attempts to review the health promoting effects of stevia with special emphasis on its application in the food system. The paper majorly features 1) the anti-hyperglycemic, anti-hypertensive, anti-caries, anti-inflammatory, and anti-cancer benefits of stevia, 2) value-added stevia-incorporated products, e.g. bakery, dairy, and beverages, 3) the effect of incorporation of stevia on physicochemical, rheological, and nutritional food properties, 4) the current status and regulatory perspective of utilizing stevia at national and international level. Due to legislative actions and growing consumer awareness, public interest in natural sweeteners has significantly increased. Since the use of artificial sweetener has recently been questioned, the data the present article provides will be useful for consumers and manufacturers that seek an alternative.

The Effect of Coconut Jelly with Stevia as a Natural Sweetener on Blood Glucose, Insulin and C-Peptide Responses in Twelve Healthy Subjects.

Coconut jelly is a popular dessert among Asian people. However, it contains high levels of sugar. The recent patents on steviol glycoside (WO2015014969A1), steviol glycoside compositions for oral ingestion or use (WO2017095932A1) and sweetener composition for preventing and improving obesity, containing glycolysis inhibitor ingredient (EP2756764B1) help to select the sweetener for development of coconut jelly. Therefore, the purposes of this study were to develop a healthier coconut jelly formula by using stevia as a natural sweetener as well as to investigate the short-term effects of Modified Coconut Jelly (MCJ) compared to Control Formula (CCJ) consumption on glycemic and insulin responses in twelve healthy participants. The sensory evaluation found that MCJ with 50% sugar replacement using stevia obtained the highest acceptability score compared to other formulas. In a cross-over design, participants were required to consume MCJ and CCJ containing 50 g of available carbohydrates. Blood samples were collected at 0 (baseline), 30, 60, 90 and 120 minutes for postprandial blood glucose, insulin, and C-peptide. The incremental Areas Under the Curve (iAUC) of blood glucose and insulin of MCJ had a lower trend than CCJ by 15.7 and 5.4 percent, respectively. MCJ consumption had blood glucose slowly decline after 60 to 120 minute. MCJ tended to decrease in postprandial blood glucose level without inducing insulin secretion. This might be an effect of stevia. Nutrient composition is lower in total sugar and higher in fiber, which has been reported as antihyperglycemia in humans. Therefore, MCJ might be an optional food product for healthy people or patients with Non-Communicable Diseases (NCDs) such as diabetes mellitus.

Simultaneous quantification of six phenylethanoid glycosides in some Turkish Scutellaria species by a new HPLC-DAD method

A new HPLC-DAD method was developed and validated for simultaneous determination of six main phenylethanoid glycosides (calceolarioside D, neocalceolarioside D, verbascoside, isoverbascoside, leucoseptoside A and martynoside) in the aerial parts of four Scutellaria L. taxa from flora of Turkey. All standard compounds showed a good linearity (R2 > 0.999) in a relatively wide concentration range (1–120 μg/mL). The LOD of the compounds was in the range of 0.104–1.295 μg/mL and the LOQ was in the range of 0.450–2.536 μg/mL. The recoveries of the selected compounds were calculated in the range of 97.46–117.85%. The amounts of the phenylethanoid glycosides showed variation in the extracts. The developed method was found to be accurate, precise and reproducible, and successfully applied to identify and quantify the phenylethanoid glycoside composition of Scutellaria species.

Evaluation of phytochemical components of various parts of Cola millenii K. Schum

Abstract This study is aimed at evaluating the qualitative and quantitative phytochemical composition of various parts (leaf, stem bark, root, seed and pulp) of Cola millenii a medicinal plant of southwestern Nigeria. The bioactive ingredients were extracted using water, ethanol and n-hexane in a solvent-percolation protocol. The qualitative phytochemical screening result revealed the presence of alkaloids, saponins and tannins in all the parts of the plant analyzed. Glycosides was found in only the seed and pulp extracts while only the seed, leaf and stem bark contain terpenoids. Also, flavonoids were found in pulp extract only whereas, anthraquinones were not found in all the plant parts. In the quantitative analyses aqueous extracts of the pulp parts contained higher saponins (1.81%), tannins (0.77%) and flavonoids (1.12%) followed by seed aqueous extract which had 0.62%, 0.51%, 0.70% and 0.47% composition of alkaloids, saponins, glycosides and terpenoids respectively. In ethanol extract, pulp extract also had higher percentage of alkaloids (1.72%), saponins (2.24%), tannins (1.15%) and flavonoids (1.21%) compared to other parts of the plant however, glycosides was found in higher percentage in seed extracts (1.10 %) than in pulp (0.21%). Moreover, in n-hexane extracts of the plant parts, pulp extracts revealed higher percentage of alkaloids (1.71%), saponins (1.40%) and flavonoids (0.93%) followed by stem bark extract whereas glycosides was present in higher percentage in seed (0.82%) than pulp extracts (0.38%). In all, the pulp and seed extracts of the plant contained more phytochemicals than other parts screened. Moreover, pulp extracts contain higher percentage of these phytochemicals than the other parts except glycosides and terpenoids which were more abundant in seed extracts than the other parts. Among different solvents used for extraction in the series, ethanol had the highest extraction capacity in pulp, leaf and stem bark extracts while n-hexane had the best extraction capacity in the seed extract. Thus, C. millenii may possess medicinal properties which may be expeditiously utilized in the pharmaceutical industry.

Identification of Terpene Lactones and Flavonol Glycosides in Preparations Based on Ginkgo Biloba Extract and a New Way of Semi-Quantitative Determination of Flavonol Glycosides by 1H NMR Spectroscopy

The composition of terpen lactones and flavonol glycosides of commercial preparation series based on Ginkgo biloba extracts was investigated by 1H NMR spectroscopy. The content of individual terpen lactones was determined using DMSO-d6 and acetone-d6 solvents. The effect of the structure of flavonol glycosides on the signal of the hydroxyl proton at a position 5 of the ring A was examined. A new approach was proposed for semiquantitative determination of the total amount of flavonol glycosides by the integral intensity of this signal, which is a superposition of the singlets in the region of 12.5–12.65 ppm of individual flavonoids in DMSO-d6. Since the corresponding signals of aglycones (quercetin, kaempferol, isorhamnetin), which are minor components of the Ginkgo biloba extracts, appear separately in a slightly different region (12.45–12.48 ppm), the proposed method can also be used for detecting adulteration of Ginkgo biloba extracts by means of the addition into them of relatively cheap aglycones or rutin as well as for assessment of the content of flavonoids of similar structure in some types of plant raw materials.

Examination of Glycoside Hydrolysis Methods for the Determination of Terpenyl Glycoside Contents of Different Hop Cultivars

The essential oil fraction of hops clearly plays a significant and important role in their contribution to the aroma of beer, yet the potential role of water-soluble flavor precursors in hops is much less certain. The study presented herein investigated a range of glycoside hydrolysis techniques on the aqueous extracts of “spent” hops obtained after supercritical CO2 extraction of hop pellets. A range of enzyme treatments, acid hydrolysis, and yeast fermentations were compared with each other and against an untreated control by measuring the volatile aroma composition of the spent hop treatments using stir-bar sorptive extraction and gas chromatography–mass spectrometry. In general, the enzyme systems show promise for investigating the broad range of glycosides in hops and offer a similar scale of aglycone delivery as yeast fermentations, whereas acid hydrolysis may offer a relatively quick gauge of total content of glycosidically bound terpene alcohols. Eighteen different hop varieties were examined for glycoside composition using one of the enzyme techniques. Selection was based on their genetic similarity or dissimilarity (pedigree), importance to the brewing community, and input from brewers, hop researchers, and hop breeders. Clear differences were apparent in the terpene alcohols following glycoside hydrolysis across these hop varieties, most notably with Columbus and Centennial hops. However, because of the high usage levels used in this study (50 g of spent hops/L of buffer), brewers are cautioned against overstating the importance of the glycoside fraction to the overall aroma of hops in beer.

Variations in the chemical composition and content of salicylic glycosides in the bark of Salix purpurea from natural locations and their significance for breeding

Willow bark is one of the few plant raw materials which contain natural active substances that have analgesic, fever-reducing, anti-inflammatory and anti-rheumatic effects. Salix purpurea, listed as widespread and common in many countries, belongs to the willow species with the highest content of salicylic compounds. The chemical composition and content of major salicylic glycosides (SGs) in the bark of S. purpurea genotypes from natural locations were investigated in this study to evaluate their applicability for pharmaceutical processing and creative breeding. Secondary metabolites were analyzed in bark extracts from 91 genotypes of S. purpurea selected from natural locations. The bark of all analyzed genotypes contained salicylic glycosides: salicin, salicortin and tremulacin; flavanones: naringenin 5-O-glucoside, naringenin 7-O-glucoside, naringenin, chalcone isosalipurposide and flavan-3-ol: catechin. Picein and populin were detected in 10% of the studied genotypes. The SG content of purple willow bark ranged from 3.04 to 10.96, pointing to high variations between S. purpurea genotypes. This study provides valuable breeding material and offers attractive prospects for the breeding of new and improved willow varieties. Varieties with the most desirable traits, grown under controlled conditions, can supply high-quality herbal materials for the pharmaceutical industry.

Effect of different drying methods on the composition of steviol glycosides in Stevia rebaudiana Bertoni leaves

Abstract Drying techniques can modify the composition of certain plant compounds. Therefore, the aim of the study was to assess the effect of different drying methods on steviol glycosides in Stevia rebaudiana Bertoni leaves. Four different drying methods were applied to Stevia rebaudiana Bertoni leaves, which were then subjected to aqueous extraction. Radiation or convection drying was performed in stoves at 60°C, whereas shade or sun drying methods were applied at 29.7°C and 70% of relative humidity. Stevioside, rebaudioside A, rebaudioside B, rebaudioside C, rebaudioside D, dulcoside A, and steviolbioside were quantified by a validated HPLC method. Among steviol glycosides, the content (g 100 g−1 dry basis) of stevioside, rebaudioside A, rebaudioside B, and rebaudioside C varied according to the drying method. The total glycoside content was higher in sun-dried samples, with no significant differences compared to shade or convection drying, whereas radiation drying adversely affected the content of rebaudioside A and rebaudioside C (p &lt;0.01) and was therefore a method lowering total glycoside content. The effect of the different drying methods was also reflected in the proportion of the sweetener profile. Convection drying could be suitable for modern food processing industries while shadow or sun drying may be a low-cost alternative for farmers.