Synthesis and structure-activity relationship of theasapogenol galactosides against Magnaporthe oryzae.

Camellia oleifera is expected to provide alternative aglycone to synthesize some saponins similar to that from Schima superba with inhibitory activity against Magnaporthe oryzae. Eight theasapogenol galactosides were synthesized via protection of adjacent hydroxyl groups by a benzylidene for regioselective glycosylation in the multi-hydroxyl sapogenin. Water soluble galactose chain connected far from liposoluble end was a key group in inhibiting the growth of M. oryzea unless theasapogenol was modified by two galactosyl groups or by one galactosyl group and one benzylidene group. The amphoteric characteristics of saponin such as saccharide group number, distance between bipolar groups play an important role in inhibiting mycelium growth of M. oryzae.

A dihydrochalcone derivative and further steroidal saponins from Sansevieria trifasciata Prain.

Phytochemical investigation of the aerial parts of Sansevieria trifasciata, one of the most common Dracaenaceae plants, has resulted in the isolation of a new dihydrochalcone derivative named trifasciatine C (1), four previously unreported steroidal saponins as two pairs of inseparable regioisomers: trifasciatosides K/L (2/3), M/N (4/5), together with the known 1,2-(dipalmitoyl)-3-O-ß-D-galactopyranosylglycerol (6), aconitic acid (7), and 1-methyl aconitic acid (8). Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D nuclear magnetic resonance) and high-resolution electronspray ionization-mass spectrometry, as well as chemical methods and comparison of their spectral data with those of related compounds. Compounds 2/3 and 4/5 were evaluated for their antiproliferative activity on Hela cells, and no significant effect was observed.

ACTIVITY OF BLACKCURRANT AND CHOKEBERRY EXTRACTS AND TWO MAJOR CYANIDIN GLYCOSIDES AGAINST LIPID MEMBRANE OXIDATION AND THEIR BINDING PROPERTIES TO ALBUMIN.

The purpose of this study was to explain how extracts from chokeberry and blackcurrant interact with the lipid phase of biological membrane and with human albumin - the main protein of blood. Aiming at better understanding of the observed biological activity of the extracts, we also conducted experiments with their main components: cyanidin-3-0-galactoside and cyanidin-3-0-ruthinoside. Antioxidant activities of extracts and cyanidin derivatives were investigated with phosphatidy1choline liposomes and AAPH as oxidation inducing factor. Fluorescent probes (merocyanin and N-phenyl-1-naphthylamine) that were located at different depths within the membrane lipid bilayer were also used. The interaction between the compounds and human serum albumin was investigated using natural fluorescence quenching. According to our study it is highly likely that the significant antioxidant activity of chokeberry and blackcurrant extracts (IC50chokeberry = 4.92 pg/mL; IC50blackbcurrant = 7.04 µg/mL) is probably due to cyjanidin's main derivatives, which protect the lipid membrane more than the extracts. In addition, it has been suggested that the compounds are anchored mainly on the membrane surface and rigidify/order the lipids in the membrane. That rigidifying effect is the key factor for understanding their antioxidant properties. Experimental results have proved that all the study compounds quench the fluorescence of HSA through a static mechanism and the main interaction forces are the Van der Waals and hydrogen bonding interactions. The results of the study have improved our knowledge on how to protect membranes against lipid peroxidation using extracts rich in anthocyanins. The results can be relevant to pharmacists and nutritionists.

Acthaside: a new chromone derivative from Acacia ataxacantha and its biological activities.

BACKGROUND: Acacia ataxacantha (Fabaceae), used in traditional medicine grows in the South-West of Bénin. Ethyl acetate extract of the barks of this species was previously reported to display various bioactivities, including antibacterial, antifungal and antioxidant activities. In the present study, we investigate the antimicrobial and antioxidant activities of compound isolated from ethyl acetate extract of Acacia ataxacantha. METHODS: Purification, isolation and structural identification of isolated compound were done using various chromatographic and spectroscopic methods. Antimicrobial activity was investigated using a two-fold serial microdilution method. The inhibitory potency of isolated compound was evaluated by kinetic experiments. The antioxidant activity was also determined using 2, 2-diphenyl-1-picrylhydrazyl. RESULTS: The isolated compound was identified as 7-hydroxy-2-methyl-6-[ß-galactopyranosyl-propyl]-4H-chromen-4-one. As far as we know, this compound, named "acthaside", reported for the first time, was active against all tested microorganisms with minimal inhibitory concentration ranging from 25 to 50 µg/ml. At 50 µl/ml, no growth was observed in almost all tested microbial after 24 h of exposure. The isolated compound had significant antioxidant activity with an IC50 value of 3.61 ± 0.12 µg/ml compared to quercetin (IC50 1.04 ± 0.01 µg/ml). CONCLUSION: The present work demonstrates that the new chromen derivative isolated from A. ataxacantha may help treat bacterial and yeast infections. However, further studies are required to clarify the mechanism of action of this compound.

[Chemical constituents from the aerial part of Sibiraea angustata].

OBJECTIVE: To study the chemical constituents from the aerial part of Sibiraea angustata. METHODS: The constituents were isolated by various chromatographic techniques (HP-20 macroporous absorption resin, Sephadex LH-20 gel, RP-MPLC and PHPLC)and their structures were determined on the basis of physicochemical properties and their spectroscopic data,as well as literatures. RESULTS: Eleven compounds were separated and identified as p-methoxycinnamic acid(I), protocatechuic aldehyde(II), quercetin(III), isorhamnetin(IV), quercetin 3-O-beta-D-galactopyranoside (V),9-0-[beta-D-glucopyranoside]-3,4,5-trimethoxy cinnamyl alcohol(VI), syringaresinol-4'-O-beta-D-monoglucoside(VII), ntin(VIII), sibiraic acid(IX), sibiscolacton(X), methyl ferulic acid(XI). CONCLUSION: Compounds I-XIII are isolated from the genus of Sibiraea for the first time.

NADES-based extraction optimization and enrichment of Cyanidin-3-O-galactoside from Rhododendron arboreum Sm.: Kinetics and thermodynamics insights.

Cyanidin-3-O-galactoside (Cy3-gal) is the most widespread anthocyanin that has been found to be applicable to nutraceutical and pharmaceutical ingredients. Nevertheless, the process of separation and purification, susceptibilities to heat, and pH inactivation present some limitations. In the present study, natural deep eutectic solvents (NADES) with an ultrasonic-assisted extraction method were briefly studied, and the recovery of Cy3-gal from Rhododendron arboreum was highlighted. The NADES, consisting of choline chloride and oxalic acid (1:1), was screened out as an extractant, and single-factor experiments combined with a two-site kinetic model were employed to describe the extraction process. Further, the work investigated ultrasound-assisted adsorption/desorption to efficiently purify Cy3-gal using macroporous resins. The optimal extraction conditions to attain maximum Cy3-gal yield was 30% water in a 50:1 (mL/g) solvent-to-sample ratio, 11.25 W/cm3 acoustic density, and 50% duty cycle for 16 min of extraction time. Under these conditions, the results revealed 23.07 ± 0.14 mg/g of Cy3-gal, two-fold higher than the traditional solvents. Furthermore, of the different resins used, Amberlite XAD-7HP showed significantly (p < 0.05) higher adsorption/desorption capacities (12.82 ± 0.18 mg/g and 10.97 ± 0.173 mg/g) and recovery (48.41 ± 0.76%) percent over other adsorbents. Experiments on the degrading behavior (40-80 °C) of the recovered Cy3-gal were performed over time, and the first-order kinetic model better explained the obtained data. In conclusion, the study asserts the use of ultrasonication with NADES and XAD-7HP resin for the improved purification of Cy3-gal from the crude extract.

New acylated flavonoid glycosides from flowers of Aerva javanica.

Chromatographic purification of ethyl acetate soluble fraction of the methanolic extract of the flowers of Aerva javanica yielded three new acylated flavone glycosides: kaempferol-3-O-ß-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 â†’ 6)]-galactoside (1), kaempferol-3-O-ß-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 â†’ 6)]-(3″-E-p-coumaroyl)galactoside (2), and kaempferol-3-O-ß-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 â†’ 6)]-(4″-E-p-coumaroyl)galactoside (3), along with p-coumaric acid (4), caffeic acid (5), gallic acid (6), eicosanyl-trans-p-coumarate (7), hexadecyl ferulate (8), and hexacosyl ferulate (9). The compounds 1-9 were characterized using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) and in comparison with the reported data in the literature. Compound 1 showed weak inhibitory activity against enzymes, such as acetylcholinesterase, butyrylcholinesterase, and lipoxygenase with IC50 values 205.1, 304.1, and 212.3 µM, respectively, whereas compounds 2 and 3 were only weakly active against the enzyme acetylcholinesterase.

Discovery and structural characterization of a novel glycosidase family of marine origin.

The genomic data on heterotrophic marine bacteria suggest the crucial role that microbes play in the global carbon cycle. However, the massive presence of hypothetical proteins hampers our understanding of the mechanisms by which this carbon cycle is carried out. Moreover, genomic data from marine microorganisms are essentially annotated in the light of the biochemical knowledge accumulated on bacteria and fungi which decompose terrestrial plants. However marine algal polysaccharides clearly differ from their terrestrial counterparts, and their associated enzymes usually constitute novel protein families. In this study, we have applied a combination of bioinformatics, targeted activity screening and structural biology to characterize a hypothetical protein from the marine bacterium Zobellia galactanivorans, which is distantly related to GH43 family. This protein is in fact a 1,3-α-3,6-anhydro-l-galactosidase (AhgA) which catalyses the last step in the degradation pathway of agars, a family of polysaccharides unique to red macroalgae. AhgA adopts a ß-propeller fold and displays a zinc-dependent catalytic machinery. This enzyme is the first representative of a new family of glycoside hydrolases, especially abundant in coastal waters. Such genes of marine origin have been transferred to symbiotic microbes associated with marine fishes, but also with some specific human populations.

Triterpene galactosides of the pouoside class and corresponding aglycones from the sponge Lipastrotethya sp.

Nine new triterpene galactosides and aglycones, along with three known compounds from the rare pouoside class, were isolated from the tropical sponge Lipastrotethya sp. collected from Micronesia. The structures of these new compounds were determined by combined spectroscopic methods and designated as pouosides F-I (4, 8, 10, and 12) and pouogenins A-E (5-7, 9, and 11). The absolute configurations of the asymmetric centers and the cyclohexenone moiety, which had been previously undetermined, were assigned by NOESY analyses and Mosher's methods. Several of these compounds exhibited weak cytotoxicity against the K562 cell line.

Depsitinuside: a new depside galactoside from an endophytic fungus isolated from Viburnum tinus.

Chromatographic purification of the extract of an endophytic fungal culture yielded depsitinuside (1), a new phenolic ester together with ergosterol (2) and (22E,24S)-24-methyl-5-α-cholesta-7,22-diene-3ß,5,6ß-triol (3). The structure of 1 was elucidated based on 1D, 2D NMR spectroscopy and high-resolution mass spectrometry, whereas the known compounds (2 and 3) were identified by (1)H NMR, mass spectrometry, and in comparison with the literature values. Compound 1 was evaluated for its enzyme inhibitory potential against acetylcholinesterase, butyrylcholinesterase and lipoxygenase, and was found inactive (10%-40% inhibition at a concentration of 2 mg/ml).

One new galloyl glycoside from fresh leaves of Psidium guajava L.

To investigate the chemical constituents of Psidium Guajava L, the EtOH/H2O extract of the fresh leaves was subjected to various chromatography. Five constituents with galloyl moiety were isolated and elucidated as 1-O-(1, 2-propanediol)-6-O-galloyl-beta-D-glucopyranoside (1), gallic acid (2), ellagic acid (3), ellagic acid-4-O-beta-D-glucopyranoside (4) and quercetin-3-O-(6"-galloyl) beta-D-galactopyranoside (5) by spectroscopic methods, including 2D NMR and HR-ESI-MS spectrometry as well as by comparison with published data. Compounds 4 and 5 were obtained from P. guajava for the first time, and compound 1 is a new polyhydroxyl compound.

Discovery of anthocyanins from cranberry extract as pancreatic lipase inhibitors using a combined approach of ultrafiltration, molecular simulation and spectroscopy.

Obesity is a chronic disease that has been causing serious problems all over the world. However, there is a lack of available therapeutic approaches to treat obesity. The FDA-approved drug orlistat has severe side effects, such as abdominal pain, flatulence and oily stool. As the therapeutic target of orlistat is pancreatic lipase, there is an urgent need for discovery of new pancreatic lipase inhibitors from natural sources that have reduced side effects compared with orlistat. In this study, ultrafiltration in combination with molecular simulation and spectroscopy was reported as an effective approach for identifying new pancreatic lipase inhibitors from anthocyanin-rich berry sources. Using this approach, four monomeric anthocyanins cyanidin-3-O-arabinoside (C3A), cyanidin-3-O-galactoside (C3Ga), peonidin-3-O-arabinoside (Pn3A) and peonidin-3-O-galactoside (Pn3Ga) from cranberries were discovered as potent pancreatic lipase inhibitors. These four cranberry anthocyanins were shown to form hydrophobic interactions and hydrogen bonds with pocket amino acid residues in molecular docking and molecular dynamics simulations. C3A showed greater impact on secondary structures of the enzyme and showed higher binding capacity with the enzyme compared with C3Ga, Pn3A and Pn3Ga as observed by CD and fluorescence spectroscopy. The structure-activity relationships were then investigated and summarized as both the structures of the B ring and glycosyl group were related to the inhibitory activities of anthocyanins. In short, our results suggested that cranberry anthocyanins could be developed as food supplements to facilitate the prevention and treatment of obesity.

Isolation of the protein tyrosine phosphatase 1B inhibitory metabolite from the marine-derived fungus Cosmospora sp. SF-5060.

In the course of bioassay-guided study on the EtOAc extract of a culture broth of the marine-derived fungus Cosmospora sp. SF-5060, aquastatin A (1) was isolated as a protein tyrosine phosphatase 1B (PTP1B) inhibitory component produced by the fungus. The compound was isolated by various chromatographic methods, and the structure was determined mainly by analysis of NMR spectroscopic data. Compound 1 exhibited potent inhibitory activity against PTP1B with IC(50) value of 0.19muM, and the kinetic analyses of PTP1B inhibition by compound 1 suggested that the compound is inhibiting PTP1B activity in a competitive manner. Aquastatin A (1) also showed modest but selective inhibitory activity toward PTP1B over other protein tyrosine phosphatases, such as TCPTP, SHP-2, LAR, and CD45. In addition, the result of hydrolyzing aquastatin A (1) suggested that the dihydroxypentadecyl benzoic acid moiety in the molecule is responsible for the inhibitory activity.

Aquastatin A, a new inhibitor of enoyl-acyl carrier protein reductase from Sporothrix sp. FN611.

Bacterial enoyl-acyl carrier protein (ACP) reductase has been confirmed as a novel target for antibacterial drug development. In this study, we determined that a fungal metabolite from Sporothrix sp. FN611 potently inhibited the enoyl-ACP reductase (FabI) of Staphylococcus aureus. Its structure identified the metabolite as aquastatin A by the MS and NMR data. Aquastatin A inhibited S. aureus FabI with an IC(50) of 3.2 microM. It also prevented the growth of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration of 16-32 microg/ml. Aquastatin A also exerted an inhibitory effect against the FabK isoform, an enoyl-ACP reductase of Streptococcus pneumoniae, with an IC(50) of 9.2 microM. The degalactosylation of aquastatin A did not affect the FabI and FabK-inhibitory or antibacterial activities, thereby suggesting that the sugar moiety within its molecular structure was not involved in these activities. The inhibitory effects of aquastatin A and its degalactosylated derivative on enoyl-ACP reductases and bacterial viability are reported for the first time in this study; these effects point to the potential that aquastatin A may be developed into a new broad-spectrum antibacterial and anti-MRSA agent.

Purification and characterization of neoagarotetraose from hydrolyzed agar.

Whitening effect, tyrosinase inhibitions, and cytotoxicity of neoagarotetraose were measured after purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, melanin content of neoagarotetraose-treated cells was as same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of 1 micron/ml and similarly inhibited at 10 and 100 microg/ml compared to those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at 1 microg/ml, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed similar IC(50) (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that neoagarotetraose generated from agar by recombinant beta-agarase might be a good candidate as a cosmetic additive for whitening effect.

Coumarin glycosides from Euphorbia soongarica (Boiss).

Two new coumarin glycosides (1 and 2), along with six known compounds (3-8), were isolated from the roots of Euphorbia soongarica. The structures of two new compounds were elucidated as aesculetin-6-O-(6'-O-galloyl)-beta-D-galactopyranoside (1) and fraxetin-8-O-(6'-O-galloyl)-beta-D-galactopyranoside (2) by spectral methods and chemical evidences.

Constituents from the seeds of Brucea javanica with inhibitory activity of Tobacco mosaic virus.

Three new constituents were obtained along with 10 known compounds from the seeds of Brucea javanica. The structures of these compounds were determined based on spectral and chemical evidence. These new compounds included a monoterpenoid glycoside and two sesquiterpenes. Bioactivity screening of these constituents showed that compounds 1, 3, 8, 9, and 13 with obvious activities in inhibiting multiplication of the Tobacco mosaic virus.

Stereochemistry and glycosidic linkages of C3-glycosylations affected the reactivity of cyanidin derivatives.

The impact of glycosylation on anthocyanin stability has largely been associated with sugar type, site, and size, with glycosyl stereochemistry being under-explored. Seven cyanidin-3-glycosides were isolated by HPLC, diluted in pH 1-9, mixed with bisulfite or ascorbic acid at pH 3, and stored for 8 weeks (25 °C, dark). Spectral changes, half-lives, and bleaching rates were determined. Cyanidin-3-galactoside was more reactive (susceptible to hydration and bleaching) than cyanidin-3-glucoside. The 1 → 2 disaccharides exhibited greater λvis-max (≤16 nm), resistance to hydration, and bleaching compared to 1 → 6 disaccharides.The 1 → 6 disaccharides had similar λvis-max (∼2 nm) to the monosaccharides but slightly improved resistance to hydration and bleaching. The tri-glycosylated anthocyanin had the greatest stability and its spectral and bleaching characteristics was intermediate to 1 → 2 and 1 → 6 disaccharides. The 1 → 2 disaccharides generally exhibited lower half-lives compared to monosaccharides; whereas, 1 → 6 disaccharides exhibited higher stability. These findings highlight the role of glycosyl assembly on anthocyanin reactivity and stability.

Simultaneous quantitative analysis of 11 flavonoid derivatives with a single marker in persimmon leaf extraction and evaluation of their myocardium protection activity.

An improved, reliable and comprehensive method for assessing the quality of the ethyl acetate extract from persimmon leaves (EAPL) and its commercial preparation, Naoxinqing (Brain and Heart Clear capsules), has been developed and validated. Based on HPLC-DAD-ESI-Q-TOF-MS analysis, myricetin-3-O-ß-D-galactoside (1), myricetin-3-O-glucoside (2), quercetin-3-O-ß-D-galactoside (3), quercetin-3-O-ß-D-glucoside (4), quercetin-3-O-(2″-O-galloyl-ß-D-galactoside) (5), quercetin-3-O-(2″-O-galloyl-ß-D-glucoside) (6), kaempferol-3-O-ß-D-galactoside (7), kaempferol-3-O-ß-D-glucoside (8), kaempferol-3-O-(2″-O-galloyl-ß-D-galactoside) (9), kaempferol-3-O-(2″-O-galloyl-ß-D-glucoside) (10), quercetin (11) and kaempferol (12) were identified from 15 batch samples. A HPLC fingerprint analytical method was established. All compounds, with the exception of compound 2, were simultaneously quantified by the single standard to determine multi-components (SSDMC) method, using kaempferol-3-O-ß-D-glucoside as the internal standard. The rate of analysis was found to be faster with the SSDMC method than with current acid hydrolysis method (Pharmacopoeia of the People's Republic of China 2015 edition) and the results were more intuitive and reliable. Three-dimensional principal component analysis revealed that there were similar characteristics in persimmon leaf from same district. Analysis of the myocardial cell protection activity of 11 monomeric compounds showed that compounds 12, 11 and 10 were the main active ingredients that produce pharmacologic functions in EAPL. Among these compounds, the bioactive constituent of myricetin-3-O-ß-D-galactoside was determined for the first time in Diospyros khaki. Thus, we have established an effective assessment method that can be applied to the comprehensive quality evaluation of EAPL extract and Naoxinqing capsule.

Cyanidin-3-O-galactoside-enriched Aronia melanocarpa extract attenuates weight gain and adipogenic pathways in high-fat diet-induced obese C57BL/6 mice.

: Aronia melanocarpa are a rich source of anthocyanins that have received considerable interest for their relations to human health. In this study, the anti-adipogenic effect of cyanidin-3-O-galactoside-enriched Aronia melanocarpa extract (AM-Ex) and its underlying mechanisms were investigated in an in vivo system. Five-week-old male C57BL/6N mice were randomly divided into five groups for 8-week feeding with a control diet (CD), a high-fat diet (HFD), or a HFD with 50 (AM-Ex 50), 100 (AM-Ex 100), or 200 AM-Ex (AM-Ex 200) mg/kg body weight/day. HFD-fed mice showed a significant increase in body weight compared to the CD group, and AM-Ex dose-dependently inhibited this weight gain. AM-Ex significantly reduced the food intake and the weight of white fat tissue, including epididymal fat, retroperitoneal fat, mesenteric fat, and inguinal fat. Treatment with AM-Ex (50 to 200 mg/kg) reduced serum levels of leptin, insulin, triglyceride, total cholesterol, and low density lipoprotein (LDL)-cholesterol. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that AM-Ex suppressed adipogenesis by decreasing CCAAT/enhancer binding protein , peroxisome proliferator-activated receptor , sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor gamma coactivator-1, acetyl-CoA carboxylase 1, ATP-citrate lyase, fatty acid synthase, and adipocyte protein 2 messenger RNA (mRNA) expressions. These results suggest that AM-Ex is potentially beneficial for the suppression of HFD-induced obesity by modulating multiple pathways associated with adipogenesis and food intake.