Glycosidic Formation Research Articles

Study on Antioxidant Activity of Purple Sweet Potato (Ipomoea Batatas) Juice Fermented with Lactobacillus plantarum B1765

Purple sweet potatoes are a source of anthocyanins, which are antioxidants. However, the anthocyanin compounds in purple sweet potatoes are naturally bound in glycosidic form, so their potential as antioxidants is still limited. Fermentation is one method that can be used to degrade glycosidic bonds to liberate free phenolics so that it can increase the antioxidant potential of purple sweet potato. This research aims to study the growth of lactic acid bacteria (LAB), pH, total titratable acid (TAT), phenolic content, anthocyanin content, and antioxidant activity of sweet potato juice (Ipomoea batatas) fermented with Lactobacillus plantarum B1765 starter culture for 0.2, 4,6,8,10,12 and 14 hours. Total LAB was measured using the Total Plate Count (TPC) method, pH was measured using a pH meter, TAT was measured using acid-base titration, total phenolic content (TPC) was measured using the Folline-Ciocalteu method, anthocyanin content used the differential pH method and antioxidant activity was measured using the radical scavenging method 2, 2-diphenyl-1-picrylhydrazyl (DPPH) which is expressed in IC50 values. The results showed that fermentation time affected (p<0.05) total LAB, pH, TAT, phenols, anthocyanin levels, and antioxidant activity in purple sweet potato juice. Total BAL increased to reach an optimum of 2.6 x 108 CFU/mL within 6 hours. However, until the end of fermentation for 14 hours, there was still a decrease in pH to 3.73, an increase in TAT reaching 0.426%, an increase in total phenolics up to 324.21 mg GAE/g, a reduction in anthocyanin levels (13.68 mg/L) and an increase in antioxidant activity with an IC50 of 47 .05 ppm which is classified as very strong. This product meets the Indonesian National Standards for fermented drinks and can potentially be a source of antioxidants.

A review on daidzein as food supplement: Exploring its phytopharmacological and preclinical status

AbstractA natural product is a compound or substance originating from a living organism and found in nature. Daidzein belongs to the class of bioflavonoids, which are plant‐derived compounds with various biological activities. Predominantly exists in soybeans and several legumes in either glycoside or aglycone forms. Its primary chemical constituents include metabolites like equol and trihydroxy isoflavone, generated through the influence of intestinal bacteria. Daidzein has exhibited pharmacological impacts on different ailments, including cardiovascular disease, cancer, diabetes, skin disorders, osteoporosis, and neurodegenerative disorders. Daidzein's mechanisms of action involve interactions with estrogen receptors, as well as its antioxidant and anti‐inflammatory properties, along with its ability to regulate apoptosis and the cell cycle. In efforts to enhance its solubility, stability, bioavailability, and targeting, daidzein has been innovatively formulated into novel dosage forms, including nanoparticles, liposomes, microemulsions, and nanosuspensions. As a promising nutraceutical, daidzein presents multiple health benefits and holds potential for various clinical applications. Additional investigation is required to comprehend the molecular mechanisms of this phenomenon and assess its safety. The purpose of this review is to provide a short description of the therapeutic properties, chemical composition, traditional use, toxicology profile, new insights on the dosage form, and future prospects of daidzein.

Quercetin activates autophagy in the distal ischemic area of random skin flaps through Beclin1 to enhance the adaptability to energy deficiency

Random flaps are frequently employed in treating substantial skin abnormalities and in surgical tissue-rebuilding interventions. The random flap technique provides flaps of specific dimensions and contours to fit the surgical incision. However, blood supply deficiency and subsequent ischemia-reperfusion injury can cause severe oxidative stress and apoptosis, eventually leading to distal necrosis, which limits the clinical application of the flap. Quercetin (QUE) is primarily found in the glycoside form in many plant parts, such as stem bark, flowers, leaves, buds, seeds, and fruits. Cellular, animal, and clinical studies have demonstrated the antioxidant, anti-apoptosis, anti-inflammatory, and activation of autophagy properties of QUE. In previous studies, high doses of QUE effectively suppressed the survival of human umbilical vein endothelial cells (HUVECs) stimulated by hydrogen peroxide. However, different concentration gradients of QUE on HUVECs revealed a significant protective effect at a concentration of 10 mM. The protective impact of QUE on HUVECs was evaluated using scratch tests, CCK-8 assays, and EDU assays. Simultaneously, a mouse model of random skin flap was created, and the impact of QUE on skin flap survival was examined by intragastric injection. The QUE group showed a significantly larger survival area of the random flap and higher blood flow intensity compared to the control group. Furthermore, the beneficial effects of QUE were reversed by the autophagy inhibitor 3-MA. Therefore, autophagy plays a significant role in the therapeutic benefits of QUE on flap survival.

Antibacterial Potential of Agarwood Leaf Extract (Aguilaria Microcarpa Baill) Against Salmonella Typhi

Aguilaria microcarpa Baill, commonly known as the Agarwood plant, is commonly used as a medicinal plant that is thought to be able to treat certain diseases because it contains chemical compounds in the form of alkaloids, flavonoids, glycosides, and tannins which can act as antioxidants and antibacterials and can be used as raw materials for the medicinal industry natural herbs. Testing in this research nature is semi-quantitative and is laboratory research in testing Aguilaria microcarpa Baill leaf extract based on characterization tests, chemical content tests, and antibacterial potential tests on growth activity of Salmonella typhi with inhibition zone parameters produced by the agar diffusion method. The results showed that Agarwood leaf extract (Aguilaria microcarpa Baill) with concentrations of 3%, 6%, 9%, and 12% w/v had the potential as an antibacterial against growth activity Salmonella thypi. The higher the concentration of the extract tested, the greater the inhibitory activity against bacterial growth. The most effective concentration is at a concentration of 12% w/v with a Sig value. 0.000 < 0.05 (Oneway Anova α = 0.05) in strong category inhibition ( 10 – 20 mm)

Furostanol Saponins and Ecdysteroids from Plants of the Genus Helleborus as Phagostimulants and Predator Deterrents for Larvae of Two Monophadnus Sawfly Species.

Sawfly species of the genus Monophadnus are specialised on Ranunculaceae plants from which the larvae can sequester furostanol saponins into the haemolymph, mainly (25R)-26-[(α-L-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl-O-β-D-glucopyranosyl-(1→3)-O-[6-acetyl-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranoside (compound 1). In this work, TLC, GC-MS, and HPLC-DAD-ESI/MS analyses together with feeding, repeated simulated attacks, and ant deterrence bioassays were conducted to extend the chemoecological knowledge about two sawfly species specialised on H. foetidus L. (Monophadnus species A) and H. viridis L. (Monophadnus species B). Larvae of Monophadnus species B were mostly feeding on the squares treated with the n-butanol fraction from H. foetidus, compound 1 being its primary non-nutritional stimulant. In contrast, all H. viridis fractions stimulated feeding, with n-hexane marginally more active. β-sitosterol within n-hexane was determined as the nutritional stimulant. Quantitative analyses demonstrated that leaves of H. viridis but not H. foetidus contain the ecdysteroids 20-hydroxyecdysone and polypodine B. Moreover, the haemolymph of Monophadnus species B larvae reared on H. viridis contained the glycosides of polypodine B and 20-hydroxyecdysone at a concentration of 2.5 to 6.8 µmol/g fresh weight of haemolymph. This concentration is several thousand times higher than the concentration range of the aglycones in their host plant (3.63 × 10-4 to 2.23 × 10-4 µmol total ecdysteroids/g fresh weight of leaves), suggesting bioaccumulation. The larvae of both species fed on H. foetidus do not show any traces of ecdysteroids in their haemolymph, indicating a facultative role of these compounds in their defence as well as their inability to endogenously synthesise these compounds. The haemolymph containing ecdysteroids was a significant feeding deterrent against Myrmica rubra L. ant workers (one of their natural predators) at 0.8 mg/mL. The larvae kept effective deterrent levels of glycosylated ecdysteroids (≅175 mM) between simulated attacks on days 1 and 2, but the levels clearly decreased on day 3 (≅75 mM). Most larvae (89%) survived a first attack but only 23% a consecutive second one. As a conclusion, we report for the first time that two Monophadnus species feeding on H. viridis sequester phytoecdysteroids into the larval haemolymph in the form of glycosides. In addition, compound 1 possesses defensive and phagostimulant activities, and we present evidence for a combined effect of furostanol saponins and ecdysteroids as repellents against ants.

Comparison of primary and secondary metabolites and antioxidant activities by solid-state fermentation of Apios americana Medikus with different fungi

This study compared the nutritional components, isoflavones, and antioxidant activities by solid-sate fermentation of Apios americana Medikus (AAM) with seven different fungi. The total fatty acid contents increased from 120.5 mg/100 g (unfermented AAM, UFAAM) to 242.0 to 3167.5 mg/100 g (fermented AAM, FAAM) with all fungi. In particular, the values of total fatty acids were highest (26.3-fold increase) in the FAAM with Monascus purpureus. The amount of total free amino acids increased from 591.69 mg/100 g (UFAAM) to 664.38 to 1603.07 mg/100 g after fermentation except for Monascus pilosus and Lentinula edodes. The total mineral contents increased evidently after fermentation with M. purpureus, F. velutipes, and Tricholoma matsutake (347.36 → 588.29, 576.59, and 453.32 mg/100 g, respectively). The UFAAM predominated isoflavone glycosides, whereas glycoside forms were converted into aglycone forms after fermentation by fungi. The bioconversion rates of glycoside to aglycone were excellent in the FAAM with M. pilosus, M. purpureus, F. velutipes, and T. matsutake (0.01 → 0.69, 0.50, 0.27, and 0.31 mg/g, respectively). Furthermore, the total phenolic contents, total flavonoid contents, and antioxidant activities by the abovementioned FAAM were high except for L.edodes. This FAAM can be used as a potential food and pharmaceutical materials.

Synthesis of plyphenol-containing cationic linear and dendrimeric peptides with anti-oxidant activity

Natural polyphenols are of great interest from the point of view of their use for the pharmacological control of oxidative stress and many diseases. However, the low bioavailability and rapid metabolism of polyphenols in the form of glycosides or aglycones stimulates the search for effective means of delivery into systemic circulation. Conjugation of polyphenols with cationic amphiphilic peptides can result in compounds with strong antioxidant activity and the ability to cross biological barriers. Such compounds may be in demand as drugs for antioxidant therapy, including for the treatment of viral, oncological and neurodegenerative diseases due to the diverse range of biological activities inherent in polyphenols and peptides. In this work, cationic linear and dendrimer amphiphilic cationic peptides were synthesized by the solid phase method, and a number of peptides were conjugated to gallic acid (Ga). Ga is a non-toxic natural phenolic acid and an important functional element of many flavonoids with high antioxidant activity. It was shown that the resulting Ga-peptide conjugates exhibited antioxidant (antiradical) activity that was 2-3 times higher than that of ascorbic acid. Other tests indicated that the addition of Ga did not affect the toxicity and hemolytic activity of the conjugates. Ga-modified peptides stimulated the transmembrane transfer of the pGL3 plasmid encoding the luciferase reporter gene; however, the addition of Ga to the N-terminus of the peptide reduced its transfection activity. Some of the resulting compounds had noticeable inhibitory activity against theE. сoli-Dh5α strain.

Acid-hydrolyzed phenolic extract of parsley (Petroselinum crispum L.) leaves inhibits lipid oxidation in soybean oil-in-water emulsions

The antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 ℃, TPC was 716.92 ± 24.43 µmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 µmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods.

Optimising the recovery of phenolic compounds and antioxidant activity from orange peels through solid-state fermentation

It is widely recognised that orange peels contain a considerable quantity of phenolics, primarily in the form of glycosides. The process of fermentation holds potential as a viable method for extracting phenolic compounds and facilitating their biotransformation into novel metabolites. The aim of this study was to assess the enhanced release of phenolic compounds through the process of solid-state fermentation of orange peels using microorganisms. Following a 6-day incubation period, the methanol extract obtained from the sample fermented with starter Banh men exhibited the highest concentration of total phenolic compounds (17.57 ± 0.34 mg GAE/g DW) and demonstrated the most significant DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (55.03%). The Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis revealed that the predominant phenolic compounds in all fermented samples were flavonoid aglycones, specifically naringenin, hesperetin, and nobiletin. Conversely, in the unfermented orange peels, the major compound observed was the glycoside derivative hesperidin.

Antioxidant and anti‑inflammatory effects of esculin and esculetin (Review).

Fraxinus chinensis Roxb is a deciduous tree, which is distributed worldwide and has important medicinal value. In Asia, the bark of Fraxinus chinensis Roxb is a commonly used traditional Chinese medicine called Qinpi. Esculetin is a coumarin compound derived from the bark of Fraxinus chinensis Roxb and its glycoside form is called esculin. The aim of the present study was to systematically review relevant literature on the antioxidant and anti-inflammatory effects of esculetin and esculin. Esculetin and esculin can promote the expression of various endogenous antioxidant proteins, such as superoxide dismutase, glutathione peroxidase and glutathione reductase. This is associated with the activation of the nuclear factor erythroid-derived factor 2-related factor 2 signaling pathway. The anti-inflammatory effects of esculetin and esculin are associated with the inhibition of the nuclear factor κ-B and mitogen-activated protein kinase inflammatory signaling pathways. In various inflammatory models, esculetin and esculin can reduce the expression levels of various proinflammatory factors such as tumor necrosis factor-α, interleukin (IL)-1β and IL-6, thereby inhibiting the development of inflammation. In summary, esculetin and esculin may be promising candidates for the treatment of numerous diseases associated with inflammation and oxidative stress, such as ulcerative colitis, acute lung and kidney injury, lung cancer, acute kidney injury.

The Effect of Fermented Jicama Extract with Lactobacillus plantarum B1765 as the Culture Starter on the Product Quality and Flavonoid Contents

Jicama (Pachyrhizus erosus) is a functional food containing phenolic compounds, with the main compounds being flavonoids. However, the presence of polyphenol oxidase and the structure of flavonoid compounds are still bound in the form of glycosides, so the bioactivity of jicama is not maximized. This study aims to determine the effects of jicama extract fermentation on product quality and increased flavonoid content in jicama. Fermentation was performed for 0, 12, 24, and 36 hours with 5% (v/v) of the starter culture, Lactobacillus plantarum B1765, at 37ºC. The result showed that fermentation times could increase Total Lactic Acid Bacteria (LAB), Total Tertitrable Acid (TTA), Total Phenolic Content (TPC), and Total Flavonoid Content (TFC). It also influenced a decrease in pH. The total LAB count was determined using the Total Plate Count method, the Total Tertitrable Acid was determined using acid-base titration, and the pH was determined using a pH meter. Total Phenolic Content was measured using the Folin-Ciocalteu method, and Total Flavonoid Content was measured using AlCl3 and potassium acetate. The analysis of the data revealed that jicama extract fermented optimum after 24 hours, with a total LAB count of 9.7x107±0.31 CFU/mL, a pH value of 4.21±0.22, a TTA of 0.376±0.025%, but TPC and TFC still increasing until 24 hours of fermentation to 16.22±0.312 mg GAE/g, and of 29.01±0.641 mg QE/g respectively. Fermentation of jicama extract with Lactobacillus plantarum B1765 increased total phenolic and total flavonoid contents and could be used as a functional food product.

Metabolic changes and isoflavone biotransformation in natto for improved nutritional distribution and bioavailability

We used LC-MS to identify the metabolic changes in soybean fermented by Bacillus subtilis DC-15 to comprehend the biochemical alterations. Total 650 distinct metabolites were observed, with amino acids, dipeptides, fatty acids, small molecule sugars, and isoflavones having the largest abundances. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the primary metabolic pathways involved during the fermentation of soybeans were related to amino acid metabolism, including beta-alanine metabolism, phenylalanine metabolism, glycine, serine, and threonine metabolism. In the gastric phase, the maximum amount of soy isoflavones was successfully converted from its glycoside form (50.04 μg/mL) to the aglycone form (104.07 μg/mL). The distribution of protein and lipid particles in natto during various stages of digestion showed changes from aggregated particles to more scattered particles. For the future development and enhancement of fermented soybean products, our metabolomic data can shed light on activated biochemical pathways and changes in metabolic pattern.

Spatial and Temporal Disparity Analyses of Glycosylated Benzaldehyde and Identification and Expression Pattern Analyses of Uridine Diphosphate Glycosyltransferase Genes in Prunus mume.

The species Prunus mume consists of uniquely aromatic woody perennials with large amounts of free aromatic substances in the flower cells. Uridine diphosphate glycosyltransferase (UGT) modifies these free aromatic substances into water-soluble glycoside-bound volatiles (GBVs) which play an important role in regulating the use of volatiles by plants for information exchange, defense, and stress tolerance. To investigate the changes in the glycosidic state of aromatic substances during the flowering period of P. mume and discern the location and expression of glycoside synthesis genes, we extracted and enzymatically hydrolyzed GBVs of P. mume and then utilized gas chromatography-mass spectrometry (GC-MS) to characterize and analyze the types and contents of GBV glycosides. Further, we identified and classified the members of the UGT gene family of P. mume using the bioinformatic method and analyzed the correlation between the expression of the UGT family genes in P. mume and the changes in glycosidic content. The results showed that the benzenoids were the main aromatic substance that was glycosylated during flowering in P. mume and that glycosidic benzaldehyde was the most prevalent compound in different flower parts and at different flowering stages. The titer of glycoside benzaldehyde gradually increased during the bud stage and reached the highest level at the big bud stage (999.6 μg·g-1). Significantly, titers of glycoside benzaldehyde significantly decreased and stabilized after flowering while the level of free benzaldehyde, in contrast, significantly increased and then reached a plateau after the flowering process was completed. A total of 155 UGT family genes were identified in the P. mume genome, which were divided into 13 subfamilies (A-E, G-N); according to the classification of Arabidopsis thaliana UGT gene subfamilies, the L subfamily contains 17 genes. The transcriptome analysis showed that PmUGTL9 and PmUGTL13 were highly expressed in the bud stage and were strongly correlated with the content of the glycosidic form of benzaldehyde at all stages of flowering. This study provides a theoretical basis to elucidate the function of UGT family genes in P. mume during flower development, to explore the mechanism of the storage and transportation of aromatic compounds in flower tissues, and to exploit industrial applications of aromatic products from P. mume.

Ethylene-responsive VviERF003 modulates glycosylated monoterpenoid synthesis by upregulating VviGT14 in grapes.

Terpenoids are important contributors to the aroma of grapes and wines. Grapes contain terpenoids in both volatile free form and non-volatile glycosidic form, with the latter being more abundant. Glycosylated terpenoids are deemed as latent aromatic potentials for their essential role in adding to the flowery and fruity bouquet of wines. However, the transcriptional regulatory mechanism underlying glycosylated terpenoid biosynthesis remains poorly understood. Our prior study identified an AP2/ERF transcription factor, VviERF003, through DNA pull-down screening using the promoter of terpenoid glycosyltransferase VviGT14 gene. This study demonstrated that both genes were co-expressed and synchronized with the accumulation of glycosylated monoterpenoids during grape maturation. VviERF003 can bind to the VviGT14 promoter and promote its activity according to yeast one-hybrid and dual-luciferase assays. VviERF003 upregulated VviGT14 expression in vivo, leading to increased production of glycosylated monoterpenoids based on the evidence from overexpression or RNA interference in leaves, berry skins, and calli of grapes, as well as tomato fruits. Additionally, VviERF003 and VviGT14 expressions and glycosylated monoterpenoid levels were induced by ethylene in grapes. The findings suggest that VviERF003 is ethylene-responsive and stimulates glycosylated monoterpenoid biosynthesis through upregulating VviGT14 expression.

Use of Novel Homochiral Thioureas Camphor Derived as Asymmetric Organocatalysts in the Stereoselective Formation of Glycosidic Bonds.

We synthesized six new camphor-derived homochiral thioureas 1-6, from commercially available (1R)-(-)-camphorquinone. These new compounds 1-6 were evaluated as asymmetric organocatalysts in the stereoselective formation of glycosidic bonds, with 2,3,4,6-tetra-O-benzyl-D-glucopyranosyl and 2,3,4,6-tetra-O-benzyl-D-galactopyranosyl trichloroacetimidates as donors, and several alcohols as glycosyl acceptors, such as methanol, ethanol, 1-propanol, 1-butanol, 1-octanol, iso-propanol, tert-butanol, cyclohexanol, phenol, 1-naphtol, and 2-naphtol. Optimization of the asymmetric glycosylation reaction was achieved by modifying reaction conditions such as solvent, additive, loading of catalyst, temperature, and time of reaction. The best result was obtained with 2,3,4,6-tetra-O-benzyl-D-galactopyranosyl trichloroacetimidates, using 15 mol% of organocatalyst 1, in the presence of 2 equiv of MeOH in solvent-free conditions at room temperature for 1.5 h, affording the glycosidic compound in a 99% yield and 1:73 α:β stereoselectivity; under the same reaction conditions, without using a catalyst, the obtained stereoselectivity was 1:35 α:β. Computational calculations prior to the formation of the products were modeled, using density functional theory, M06-2X/6-31G(d,p) and M06-2X/6-311++G(2d,2p) methods. We observed that the preference for β glycoside formation, through a stereoselective inverted substitution, relies on steric effects and the formation of hydrogen bonds between thiourea 1 and methanol in the complex formed.

Synthesis of New Glycosylamine Derivatives based on Carbohydrates

Background: Glycosylamine play an important role in living organisms. Most plants store their chemical resources in the form of inactive glycosides, which are broken down and con-verted into sugar in the body of herbivores by hydrolyzing enzymes. Glycosylamine are obtained from the secondary metabolism of plants and consist of two parts. One part of it contains sugar like glucose and is inactive in most substances, and has a good effect on the solubility of the glycosyla-mine derivatives and its absorption and even its transfer from one organ to another. The therapeutic effect is related to the second part, which is called aglycan (or aglucan). Glycosylamine derivatives form a large group of valuable medicinal substances, which at the same time include some of the most dangerous and toxic substances in nature. These substances are present in many groups of flowering plants. Glycosides are made in different ways in different metabolic pathways. These materials have a complex and special chemical structure and leave special effects on the human body. Glycosylamine derivatives are called O-glycosid, N-glycosid, S-glycosid in terms of atoms coupling to anomeric carbon. Carbohydrate esterification reaction to prepare new glycosylamine derivatives is one of the most important carbohydrate reactions. The anomeric position of carbohy-drates with strong leaving groups is very important for the preparation of glycosides. Preparation of glycosylamine derivatives based on acetylated carbohydrates is the main purpose of this article. Dif-ferent carbohydrates were acetylated under mild conditions and high yields. The anomeric position was deacetylated by a magnesium oxide heterogeneous catalyst in methanol solvent. In order to pre-pare new glycosides acetylated/ deacytylated carbohydrate reacted with N-Methyl-(naphtha-2-ylmethoxy)amine. The final product was identified by various spectroscopic methods. Methods: Anhydrous sodium acetate (4 g) and α-D-glucose (28 mg, 5 g) were mixed. The mixture was transferred to a 200 ml Round-bottom flask . Acetic acid (260 mg, 25 ml) was added to the reaction mixture. The reaction mixture was heated in a boiling water bath for 2 h until complete dissolution of the glucose. Then 100 ml of ice was added. After 1 hour, White crystals formed and were washed with cold water. And then 1 mol of glucose pentaacetate per 50 ml of methanol was dissolved by a magnetic stirrer. After thatMgO (0.2gr) was added to the reaction mixture. The re-action mixture was refluxed at room temperature within 4-5 hours. After 5 hours, the solvent was removed and separated by chromatography. It is then washed with hexane and crystallized by ether-hexane. And the final step reacted with N-Methyl- (naphtha-2-ylmethoxy) amine in order to prepare new glycosylamine derivatives. Results: Magnesium oxide in methanol solvent is one of the best effective catalysts in the deacetyla-tion of the anomer position of acetylated carbohydrates. It is done under ambient temperature and in very easy conditions and makes carbohydrates susceptible to extensive chemical reactions. One of these reactions is the formation of glycosides. Various carbohydrates are acetylated by acetic anhy-dride in the presence of sodium acetate, and the anomeric position is deacetylated by a heterogeneous catalyst. In order to prepare N-glycoside, the glycosides are reacted with N-alkoxy N-methylglycosyl amine. The final products are identified by various spectroscopic methods. Conclusion: Glucose, mannose, for example, were acetylated by acetic anhydride in the presence of sodium acetate. And the anomeric position of pentaacetate glucose was selectively deacetylated with magnesium oxide in a methanol solvent. Then, the reaction for the preparation of glycosylamine de-rivatives was carried out under very mild and easy conditions. The aminoglycosides synthesized in this article are used as raw materials for the synthesis of a wide range of antibacterials.

An evaluation of the antioxidant potential and in vitro enzyme inhibition profile of selected bryophytes from Northeast Anatolia (Türkiye)

Interest in the use of bryophytes in pharmaceutical, cosmetic, and food industrial applications is growing worldwide due to their secondary metabolites. In this study, n-hexane crude extracts and further fractions (aqueous, ethyl acetate and n-butanol) of aqueous ethanol (80:20, ethanol:H2O, v/v) were obtained from five different bryophytes (Pellia epiphylla, Conocephalum conicum, Porella platyphylla, Plagiomnium cuspidatum and Mnium spinulosum) collected from Trabzon, Türkiye. The total phenolic compound (TPC) content, antioxidant capacity (AC) and enzyme inhibition activity (acetylcholine esterase, butyrylcholine esterase, tyrosinase, α-amylase and α-glucosidase) of the extracts and fractions were species-specific and varied significantly between the crude extracts and fractions. Among the different bryophytes, Porella platyphylla and Pellia epiphylla in n-butanol and Plagiomnium cuspidatum and Mnium spinulosum in ethyl acetate fraction exhibited the highest TPC contents and AC values. The contents of phenolic acids liberated in free, ester and glycoside forms were also species-specific. p-Hydroxybenzoic acid (p-HBA) in free form in P. cuspidatum and P. platyphylla, p-coumaric acid (p-CoA) in ester form and m-hydroxybenzoic acid (m-HBA) in glycoside form in M. spinulosum were the major phenolic acids in the bryophytes. The n-hexane extracts of the bryophytes, in particular M. spinulosum, had IC50 values ​​almost 100 times lower than acarbose. This suggests that M. spinulosum in particular may represent a possible candidate for the production of new antidiabetic agents. Communicated by Ramaswamy H. Sarma

Identification of Genes Responsible for the Synthesis of Glycitein Isoflavones in Soybean Seeds.

Soybean (Glycine max (L.) Merrill) isoflavones are among the most important secondary metabolites, with functional benefits for human health. Soybeans accumulate three aglycone forms of isoflavones: genistein, daidzein, and glycitein. Soybean landrace Kumachi-1 does not accumulate malonylglycitin at all. Gene structure analysis indicated that Glyma.11G108300 (F6H4) of Kumachi-1 has a 3.8-kbp insertion, resulting in a truncated flavonoid 6-hydroxylase (F6H) sequence compared to the wild-type sequence in Fukuyutaka. Mapping experiments using a mutant line (MUT1246) with a phenotype similar to that of Kumachi-1, with a single-nucleotide polymorphism (SNP) in F6H4, revealed co-segregation of this mutation and the absence of glycitein isoflavones. We also identified a mutant line (K01) that exhibited a change in the HPLC retention time of glycitein isoflavones, accumulating glycoside and malonylglycoside forms of 6-hydroxydaidzein. K01 contains an SNP that produces a premature stop codon in Glyma.01G004200 (IOMT3), a novel soybean isoflavone O-methyltransferase (IOMT) gene. We further analyzed transgenic hairy roots of soybeans expressing Glyma.11G108300 (F6H4) and Glyma.01G004200 (IOMT3). Those overexpressing F6H4 accumulated malonylglycoside forms of 6-hydroxydaidzein (M_6HD), and co-expression of F6H4 and IOMT3 increased the level of malonylglycitin but not of M_6HD. These results indicate that F6H4 and IOMT3 are responsible for glycitein biosynthesis in soybean seed hypocotyl.

Synthesis and Biological Properties of Polyphenol-Containing Linear and Dendrimeric Cationic Peptides.

Natural polyphenols are promising compounds for the pharmacological control of oxidative stress in various diseases. However, low bioavailability and rapid metabolism of polyphenols in a form of glycosides or aglycones have stimulated the search for the vehicles that would provide their efficient delivery to the systemic circulation. Conjugation of polyphenols with cationic amphiphilic peptides yields compounds with a strong antioxidant activity and ability to pass through biological barriers. Due to a broad range of biological activities characteristic of polyphenols and peptides, their conjugates can be used in the antioxidant therapy, including the treatment of viral, oncological, and neurodegenerative diseases. In this work, we synthesized linear and dendrimeric cationic amphiphilic peptides that were then conjugated with gallic acid (GA). GA is a non-toxic natural phenolic acid and an important functional element of many flavonoids with a high antioxidant activity. The obtained GA-peptide conjugates showed the antioxidant (antiradical) activity that exceeded 2-3 times the antioxidant activity of ascorbic acid. GA attachment had no effect on the toxicity and hemolytic activity of the peptides. GA-modified peptides stimulated the transmembrane transfer of the pGL3 plasmid encoding luciferase reporter gene, although GA attachment at the N-terminus of peptides reduced their transfection activity. Several synthesized conjugates demonstrated the antibacterial activity in the model of Escherichia coli Dh5α growth inhibition.

Thiourea-Cu(OTf)2/NIS-synergistically promoted stereoselective glycoside formation with 2-azidoselenoglycosides or thioglycosides as donors.

A novel promoter system for glycosylation is described. A catalytic amount of thiourea and Cu(OTf)2 together with a slight excess of N-iodosuccinimide synergistically promotes glycosylation at room temperature. The combination of reagents applies to some 2-azidoselenoglycoside and thioglycoside donors. A wide range of alcoholic acceptors underwent smooth conversion to O-(2-azido)glycosides with good stereoselectivities. In addition, the value of this method has been highlighted by its convenient operation and outstanding functional group compatibility.