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A reduced proteasome activity tiles excessive amyloid growth during the progress of protein conformational diseases (PCDs). Hence, the development of safe and effective proteasome enhancers represents an attractive target for the therapeutic treatment of these chronic disorders. Here we analyze two natural diastereoisomers belonging to the family of flavonolignans, Sil A and Sil B, by evaluating their capacity to increase proteasome activity. Enzyme assays carried out on yeast 20S (y20S) proteasome and in parallel on a permanently "open gate" mutant (α3ΔN) evidenced that Sil B is a more efficient 20S activator than Sil A. Conversely, in the case of human 20S proteasome (h20S) a higher affinity and more efficient activation is observed for Sil A. Driven by experimental data, computational studies further demonstrated that the taxifolin group of both diastereoisomers plays a crucial role in their anchoring to the α5/α6 groove of the outer α-ring. However, due to the different stereochemistry at C-7" and C-8" of ring D, only Sil A was able to reproduce the interactions responsible for h20S proteasome activation induced by their cognate regulatory particles. The provided silybins/h20S interaction models allowed us to rationalize their different ability to activate the peptidase activities of h20S and y20S. Our results provide structural details concerning the important role played by stereospecific interactions in driving Sil A and Sil B binding to the 20S proteasome and may support future rational design of proteasome enhancers.

Gymnema sylvestre is a commonly used herb in Ayurvedic medicine. The demand for its extracts in the commercial and pharmaceutical fields has been steadily increasing in recent years. Its extracts are used to treat various ailments as well as for their antimicrobial properties. This study has evaluated the antimicrobial effects of different G. sylvestre extracts and of eight triterpenes isolated from the most active extract on six bacterial poultry pathogens i.e. Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterobacter aerogenes. In particular, it has been evaluated the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of all extracts and isolated triterpenes. Finally, the cytotoxicity activity of triterpenes was evaluated by MTT assay and their antioxidant activity in basal and oxidant conditions by DCFH-DA assay.

Introduction: Artemisia annua is a small herbaceous plant belonging to the Asteraceae family declared therapeutic by the World Health Organisation, in particu- lar for its artemisinin content, an active ingredient at the base of most antimalarial treatments, used every year by over 300 million people. In the last years, owing to low artemisinin content, research of new ways to increase the yield of the plant matrix has led to the use of the total extract taking advantage from the synergic and stabilising effects of the other components. Objective: In this work we evaluated and compared the content of artemisinin and scopoletin in extracts of A. annua collected in the Campania Region (southern Italy), by two different extraction processes. Methodology: Artemisia annua plants were extracted by traditional maceration (TM) in hydroalcoholic solution as a mother tincture prepared according to the Euro- pean Pharmacopeia and by pressurised cyclic solid–liquid (PCSL) extraction, a new generation method using the Naviglio extractor. Results: The results showed that the PCSL extraction technique is more effective than traditional methods in extracting both phytochemicals, up to 15 times more, reducing the extraction times, without using solvents or having risks for the opera- tors, the environment and the users of the extracts. Conclusion: The Naviglio extractor provides extracts with an artemisinin and scopoletin content eight times higher than the daily therapeutic dose, which should be evaluated for its stability over time and biological properties for possible direct use for therapeutic purposes.

Gymnema sylvestre has been used in Asian traditional medicine for its anti-microbial, anti-hypercholesterolemic, hepatoprotective and sweet suppressing properties and activities. G. sylvestre has also been used extensively in chewing gum, as a health food for preventing obesity and diabetes, and as a tea. This study has evaluated the total phenolic content and antioxidant activity of the aqueous and organic G. sylvestre extracts and their sub-fractions for the initial characterization of the biological properties of the isolated compounds. An in vivo cell model was used to calculate the concentration inhibiting cell growth by 50% and the ability to exert antioxidant activity. All compounds inhibit cell growth in a dose-dependent manner, with an IC 50 value ranging between 29 and 1462 μM. The effects on intracellular ROS levels are extremely variable, but it is of interest that some of the compounds appear to display an antioxidant effect.

During the lipidomic analysis of red blood cell membranes, the distribution and percentage ratios of the fatty acids are measured. Since fatty acids are the key constituents of cell membranes, by evaluating their quantities it possible to understand the general health of the cells and to obtain health indicators of the whole organism. However, because the analysis is precise, it is necessary to ensure that the blood does not undergo significant variations between the point of collection and analysis. The composition of the blood may vary dramatically weeks after collection, hence, here an attempt is made to stabilize these complex matrixes using antioxidants deposited on the paper cards on which the blood itself is deposited.

The biological relevance of tetramolecular G-quadruplexes especially as anti-HIV agents has been extensively reported in the literature over the last years. In the light of our recent results regarding the slow G-quadruplex folding kinetics of ODNs based on d(TGGGAG) sequence, here we report a systematic anti-HIV screening to investigate the impact of the G-quadruplex folding on their anti-HIV activity. In particular, varying the single stranded concentrations of ODNs, it has been tested a pool of ODN sample solutions with different G-quadruplex concentrations. The anti-HIV assays have been designed favouring the limited kinetics involved in the tetramolecular G4-association based on the d(TGGGAG) sequence. Aiming to determine the stoichiometry of G-quadruplex structures in the same experimental conditions of the anti-HIV assays, a native gel electrophoresis was performed. The gel confirmed the G-quadruplex formation for almost all sample solutions while showing the formation of high order G4 structures for the more concentrated ODNs solutions. The most significant result is the discovery of a potent anti-HIV activity of the G-quadruplex formed by the natural d(TGGGAG) sequence (IC50 = 14 nM) that, until now, has been reported to be completely inactive against HIV infection.

New silibinin phosphodiester glyco-conjugates were synthesized by efficient phosphoramidite chemistry and were fully characterized by 2D-NMR. A wide-ranging study focused on the determination of their pKa and E° values as well as on their radical scavenging activities by different assays (DPPH, ABTS+ and HRSA) was conducted. The new glyco-conjugates are more water-soluble than silibinin, and their radical scavenging activities are higher than those of silibinin. The conjugation therefore improves both the water solubilities and antioxidant activities of the flavonolignan moieties. The serum stability was evaluated under physiological conditions, and the glyco-conjugates degraded with half-lives of 40-70 h, making them useful in pro-drug approaches. We started by treating androgen-dependent prostate cancer (PCa) LNCaP cells and then expanded our studies to androgen-independent PCa PC3 and DU145 cells. In most cases, the new derivatives significantly reduced both total and live cell numbers, albeit at different levels. Anti-HIV activities were evaluated and the glucosamine-phosphate silibinin derivative showed higher activity (IC50 = 73 μM) than silibinin.

International audience; By exploiting the regioselective protection of the hydroxyl groups of silibinin along with the well-known phosphoramidite chemistry, we have developed an efficient strategy for the synthesis of new silibinin-modified species, which we have named Phosphate-Linked Silibinin Dimers (PLSd), in which the monomer units are linked by phosphodiester bonds. The antioxidant abilities of the new PLSd were estimated on HepG2 cells using DPPH free radical scavenging and xanthine/xanthine oxidase assays. The new phosphate-metabolites showed a higher anti-oxidant activity than the silibinin, as well as very low toxicity. The ability to scavenge reactive oxygen species (ROS) such as singlet oxygen () and hydroxyl radical () reveals that the two dimers are able to scavenge about two times more effectively than silibinin. Finally, solubility studies have shown that the PLSd present good water solubility (more than 20 mg·L−1) under circumneutral pH values, whereas the silibinin was found to be very poorly soluble (less than 0.4 mg·L−1) and not stable under alkaline conditions. Together, the above promising results warrant further investigation of the future potential of the PLSd as anti-oxidant metabolites within the large synthetic polyphenols field.

Because plants are estimated to produce over 200,000 metabolites, research into new natural substances that can be used in the pharmaceutical, agrochemical and agro-industrial production of drugs, biopesticides and food additives has grown in recent years. The global market for plant-derived drugs over the last decade has been estimated to be approximately 30.69 billion USD. A relevant specific example of a plant that is very interesting for its numerous pharmacological properties, which include antidiabetic, anticarcinogenic, and neuroprotective effects is Gymnema sylvestre, used as a medicinal plant in Asia for thousands of years. Its properties are attributed to triterpenoidic saponins. In light of the considerable interest generated in the chemistry and pharmacological properties of G. sylvestre triterpenes and their analogues, we have undertaken this review in an effort to summarise the available literature on these promising bioactive natural products. The review will detail studies on the isolation, chemistry and bioactivity of the triterpenoids, which are presented in the tables. In particular the triterpenoids oxidised at C-23; their isolation, distribution in different parts of the plant, and their NMR spectral data; their names and physico-chemical characterisation; and the biological properties associated with these compounds, with a focus on their potential chemotherapeutic applications.

The pharmacological relevance of ODNs forming G-quadruplexes as anti-HIV agents has been extensively reported in the literature over the last few years. Recent detailed studies have elucidated the peculiar arrangement adopted by many G-quadruplex-based aptamers and provided insight into their mechanism of action. In this review, we have reported the history of a strong anti-HIV agent: the 6-mer d(TGGGAG) sequence, commonly called “Hotoda’s sequence„. In particular, all findings reported on this sequence and its modified sequences have been discussed considering the following research phases: (i) discovery of the first 5′-modified active d(TGGGAG) sequences; (ii) synthesis of a variety of end-modified d(TGGGAG) sequences; (iii) biophysical and NMR investigations of natural and modified Hotoda’s sequences; (iv); kinetic studies on the most active 5′-modified d(TGGGAG) sequences; and (v) extensive anti-HIV screening of G-quadruplexes formed by d(TGGGAG) sequences. This review aims to clarify all results obtained over the years on Hotoda’s sequence, revealing its potentiality as a strong anti-HIV agent (EC50 = 14 nM).

New phosphorylating reagents 1 and 2 were prepared in three steps from 4-hydroxybenzaldehyde. They showed good efficiency in the solid phase synthesis of 5′-phosphate monoester nucleosides. End-phosphate DNA sequence synthesis demonstrated the efficiency of the new reagents ( 1 and 2 ) according to the general procedure of automated DNA synthesis. The oxidation of P(III) to P(V) and the removal of benzyl protecting groups were achieved in a single step by treatment with a 0.02 M I 2 /pyridine/H 2 O solution. Due to this one-pot treatment, it is possible to use the phosphorylating reagents ( 1 and 2 ) for the synthesis of base-sensitive ODNs. The reagents 1 and 2 are unique among phosphorylating reagents.

In recent years, many studies have highlighted the consistent finding of tramadol (TRA) in the effluents from wastewater treatment plants (WTPs) and also in some rivers and lakes in both Europe and North America, suggesting that TRA is removed by no more than 36% by specific disinfection treatments. The extensive use of this drug has led to environmental pollution of both water and soil, up to its detection in growing plants. In order to expand the knowledge about TRA toxicity as well as the nature of its disinfection by-products (DBPs), a simulation of the waste treatment chlorination step has been reported herein. In particular, we found seven new by-products, that together with TRA, have been assayed on different living organisms (Aliivibrio fischeri, Raphidocelis subcapitata and Daphnia magna), to test their acute and chronic toxicity. The results reported that TRA may be classified as a harmful compound to some aquatic organisms whereas its chlorinated product mixture showed no effects on any of the organisms tested. All data suggest however that TRA chlorination treatment produces a variety of DBPs which can be more harmful than TRA and a risk for the aquatic environment and human health.

The methanol extracts of the aerial part of four ethnomedicinal plants of Mediterranean region, two non-seed vascular plants, Equisetum hyemale L. and Phyllitis scolopendrium (L.) Newman, and two Spermatophyta, Juniperus communis L. (J. communis) and Cotinus coggygria Scop. (C. coggygria), were screened against four human cells lines (A549, MCF7, TK6 and U937). Only the extracts of J. communis and C. coggygria showed marked cytotoxic effects, affecting both cell morphology and growth. A dose-dependent effect of these two extracts was also observed on the cell cycle distribution. Incubation of all the cell lines in a medium containing J. communis extract determined a remarkable accumulation of cells in the G2/M phase, whereas the C. coggygria extract induced a significant increase in the percentage of G1 cells. The novelty of our findings stands on the observation that the two extracts, consistently, elicited coherent effects on the cell cycle in four cell lines, independently from their phenotype, as two of them have epithelial origin and grow adherent and two are lymphoblastoid and grow in suspension. Even the expression profiles of several proteins regulating cell cycle progression and cell death were affected by both extracts. LC-MS investigation of methanol extract of C. coggygria led to the identification of twelve flavonoids (compounds 1-11, 19) and eight polyphenols derivatives (12-18, 20), while in J. communis extract, eight flavonoids (21-28), a alpha-ionone glycoside (29) and a lignin (30) were found. Although many of these compounds have interesting individual biological activities, their natural blends seem to exert specific effects on the proliferation of cell lines either growing adherent or in suspension, suggesting potential use in fighting cancer.

To investigate what properties make tetramolecular G-quadruplex ODNs good anti-HIV aptamers, we studied the stoichiometry and the self-assembly kinetics of the highly active 5'-end modified G-quadruplexes based on the d(TGGGAG) sequence. Our results demonstrate that the 5'-end conjugation does not necessarily increase the folding rate of the G-quadruplex; indeed, it ascribes anti-HIV activity. Unexpectedly, the G4-folding kinetics of the inactive G4 is similar to that of the 5'-end modified sequences. ESI-MS studies also revealed the formation of higher order G4 structures identified as octameric complexes along with tetramolecular G-quadruplexes.

We describe the facile syntheses of new modified oligonucleotides based on d(TG3AG) that form bimolecular G-quadruplexes and possess a HEG loop as an inversion of polarity site 3'-3' or 5'-5' and aromatic residues conjugated to the 5'-end through phosphodiester bonds. The conjugated hairpin G-quadruplexes exhibited parallel orientation, high thermal stability, elevated resistance in human serum and high or moderate anti-HIV-1 activity with low cytotoxicity. Further, these molecules showed significant binding to HIV envelope glycoproteins gp120, gp41 and HSA, as revealed by SPR assays. As a result, these conjugated hairpins represent the first active anti-HIV-1 bimolecular G-quadruplexes based on the d(TG3AG) sequence. publisher: Elsevier articletitle: Hairpin oligonucleotides forming G-quadruplexes: New aptamers with anti-HIV activity journaltitle: European Journal of Medicinal Chemistry articlelink: http://dx.doi.org/10.1016/j.ejmech.2014.10.030 content_type: article copyright: Copyright © 2014 Elsevier Masson SAS. All rights reserved. ispartof: European Journal of Medicinal Chemistry vol:89 pages:51-8 ispartof: location:France status: published

b ) Tecno-Bios srl, Piazza San G. Moscati, I-82030 Apollosa (BN) c ) Dipartimento di Farmacia - via D. Montesano 49, I-80131, Napoli d ) AIPRAS Onlus-Associazione Italiana per la Promozione delle Ricerche sullAmbiente e la Salute umana-Via Nazionale 50, I-82030 Dugenta (BN) Silibinin, the major flavonolignan of silymarin, displays a broad spectrum of biological features that are generally ascribed to its antioxidant properties. Silibinin occurs in two diastereoisomeric forms, i.e., silybins A and B, in a ratio of ca. 1 : 1. With a simple and robust purification method, it is now possible to obtain silybins A and B in pure forms, in g-scale amounts, and within a short period of time. Herein, we describe an efficient synthesis strategy to obtain a variety of new and more H2O-soluble derivatives from the single silybins in which the 9''-OH group was converted to a sulfate, N3, phosphodiester, or NH2 group via a solution-phase approach. Thus, eight new compounds have been synthesized, purified by HPLC analysis, and characterized by NMR and MS analyses. To conduct experiments to clarify the many biological properties of pure silibinin diastereoisomers and their derivatives, the synthetic compounds were tested by using the DPPH assay to evaluate their antioxidant activities. The results, even if only for a small number of derivatives, revealed that some of these compounds are much more active than their parent compounds. It is also interesting to consider the synergetic effects.

New silibinin glyco-conjugates have been synthesized by efficient method and in short time. Exploiting our solution phase strategy, several structurally diverse silibinin glyco-conjugates (gluco, manno, galacto, and lacto-) were successfully realized in very good yields and in short time. In preliminary study to evaluate their antioxidant and neuroprotective activities new derivatives were subjected to DPPH free radical scavenging assay and the Xanthine oxidase (XO) inhibition models assay. Irrespective of the sugar moiety examined, new glyco-conjugates are more than 50 times water-soluble of silibinin. In the other hand they exhibit a radical scavenging activities slightly higher than to silibinin and XO inhibition at least as silibinin. (C) 2014 Elsevier Ltd. All rights reserved.

In the literature there are hundreds of articles, the first dating back to 1866 and the last to 2014, on gymnemic acid, isolated from Gy mnema sylvestre, from its isolation to the determination of its biological activities. Gymnemic acid has a CAS number but its structure is not specified. Studies during the second half of the 1970s clearly demonstrated that what was being referred to as gymnemic acid is actually a very complex mixture of dozens of substances, belonging to different classes of natural compounds. This plant, whose infusions or complex mixtures of its metabolites are the basis for many formulas sold in pharmacies and by herbalists, has anti-diabetic and slimming effects. It is certainly misleading to talk about gymnemic acid as a specific molecule. There may be doubts about the exact composition of the products, and consequently about their origin and the claimed effects.

Novel conjugated G-quadruplex-forming d(TG(3)AG) oligonucleotides, linked to hydrophobic groups through phosphodiester bonds at 5'-end, have been synthesized as potential anti-HIV aptamers, via a fully automated, online phosphoramidite-based solid-phase strategy. Conjugated quadruplexes showed pronounced anti-HIV activity with some preference for HIV-1, with inhibitory activity invariably in the low micromolar range. The CD and DSC monitored thermal denaturation studies on the resulting quadruplexes, indicated the insertion of lipophilic residue at the 5'-end, conferring always improved stability to the quadruplex complex (20 < Delta Tm < 40 degrees C). The data suggest no direct functional relationship between the thermal stability and anti-HIV activity of the folded conjugated G-quartets. It would appear that the nature of the residue at 50 end of the d(TG(3)AG) quadruplexes plays an important role in the thermodynamic stabilization but a minor influence on the anti-HIV activity. Moreover, a detailed CD and DSC analyses indicate a monophasic behaviour for sequences I and V, while for ODNs (II-IV) clearly show that these quadruplex structures deviate from simple two-state melting, supporting the hypothesis that intermediate states along the dissociation pathway may exist. (C) 2014 Elsevier Ltd. All rights reserved.

"Chemically modified siRNAs were synthesized to enhance the corresponding silencing activities. The introduced modifications endowed siRNAs with high silencing effect, long RNAi persistence and better serum resistance. The-oretical data allowed to correlate the observed siRNAs interfering performance with the peculiar interactions with PAZ." Chemically modified siRNAs were synthesized to enhance the corresponding silencing activities. The introduced modifications endowed siRNAs with high silencing effect, long RNAi persistence, and better serum resistance. Theoretical data allowed us to correlate the observed siRNAs interfering performance with the peculiar interactions with PAZ. © 2012 American Chemical Society.