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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.

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.

The aim of this work is to compare new and traditional extraction methods to obtain silymarin from

Sartans are chemical compounds with antagonistic action towards the AT1 receptors of angiotensin II, a multifunctional peptide with vasoconstrictor action and one of the main peptides responsible for regulating blood pressure. Losartan (progenitor of the group), valsartan, irbesartan, candesartan, eprosartan, telmisartan and a few other compounds belong to this class. The use of sartans, introduced in the mid-90s of the last century, has quickly spread mainly due to the alleged reduction in the incidence of certain adverse effects of varying severity (cough, angioedema) associated with the intake of ACE inhibitors. Their very strong commercial success together with their low metabolic degradation and high environmental persistence has consecrated them as emerging pollutants in just 20 years. This review presents a complete picture of sartans in relation to their chemical structure, chemical-physical properties and by-products in aqueous solutions as well as under oxidative and photodegradative conditions, their environmental presence and knowledge known to date and their fate in wastewater treatment plants.

The aim of this work is to compare new and traditional extraction methods to obtain silymarin from Silybum marianum, a biennial herbaceous plant of the Asteraceae family, present throughout the Mediterranean basin and used to treat several diseases. Silymarin primarily contains flavonolignans and flavonoids and is used in some pharmaceutical preparations to improve of liver function and as a protective against some hepatotoxins. In six extracts obtained by new and traditional extraction methods, the total contents of silymarin and its main flavonolignans, total phenols and condensed tannins were evaluated in addition to their respective antioxidant capacities. By the Naviglio extractor, that is a rapid solid-liquid dynamic extraction method, it is possible to obtain a fraction quantitatively more abundant than other methods, and with a lower content of tannins and phenolic compounds but with a higher content of flavonolignans, rare and expensive, and therefore easier to separate and purify.

Polyphenols are active compounds of the medicinal plants widely distributed in nature. Despite the few and common biosynthetic origins, polyphenols encompass many subclasses of structurally different entities with a variety of pharmacological properties. Many studies suggests that the mechanisms by which plant polyphenols exert their protective actions against various diseases, in part are due to their redox properties. Silibinin belongs to flavonolignan class and is a major component (approximately 30%) of the Silymarin complex extracted from milk thistle [Silybum marianum (L.) Gaertn. Carduus marianus L., Asteraceae]. Silibinin exists as a mixture of two diastereomers: Silybin A and Silybin B. Silibinin has long been studied for a large variety of pharmacological properties ranging from its antioxidant activity to neuroprotective and antiviral activities. Unfortunately, its in vivo applications are rather hampered by its very low bioavailability mainly due to low water solubility. In an attempt to improve its biological properties and facilitate the in vivo applications, we have developed an efficient strategy for the synthesis of Silibinin modified namely Phosphate-Linked Silibinin dimers (PLSd) in which the Silibinin monomer units are linked by phosphodiester bond (Figure). Exploiting the selective protection of Silibinin’s hydroxyl groups, we carried out a synthetic approach using the phosphoramidite chemistry. Water solubility of dimers, radical scavenger activity as well as their ability to react with reactive oxygen species (ROS) were determined. In particular, dimers reactivity with 1O2 and HO∙ was determined by use of Rose Bengal (RB) and hydrogen peroxide (H2O2) as respective ROS sources. For this purpose, laser flash photolysis (LFP) experiments were coupled with a kinetic competition approach. In addition to scavenging activity, the serum stability and cytoprotective (X/XO assay on HepG2 cells) behavior of dimers were evaluated.

In the last years, G-rich oligonucleotides (GROs) able to form G-quadruplexes, have attracted considerable interest in biological and therapeutic fields. G-quadruplex are among the most studied DNA structures because they are thought to be involved in important biological processes such as the modulation of gene expression; in addition they present a large variety of biological properties ranging from anticancer to antiviral activities. In all cases, the G-quadruplex formation is a crucial prerequisite for the biological effects. Recently, we reported the synthesis and full characterization of a mini-library of G quadruplex ODNs carrying aryl groups at the 5’-end through a phosphodiester bond and endowed with prominent anti-HIV activity. In this frame, we report here, the synthesis of new Riboflavin-Nucleoside (RF, Vitamin B) building block in which the ribityl chain is rigidified by 2',4' benzylidene group, the 5'-OH function is protected with DMT group and the 3’ position is functionalized with phosphoramidite. The new Riboflavin building block is incorporated into different ODN sequences able to form Gquadruplex structures using the well known phosphoramidite chemistry. This research project has been encouraged by recent studies on the use of RF as useful tool for both in vivo and in vitro studies: the Riboflavin is internalized through RF transporters and is one of the most efficient natural photosensitizers. Several modified ODN sequences have been synthesized with a solid phase synthetic approach in good yields; their biophysical and biological characterization has been carried out in order to evaluate the effect of RF-nucleotide insertion into G-quadruplex arrangements and their anti-HIV activity.

Potatoes are a staple food for over a billion people worldwide, a primary dietary source of carbohydrates, and a vital crop to the agricultural economy of South America, Africa, East Asia and Central Asia. Potatoes occupy third place (after rice and wheat) on the list of foods on which the world depends for food security. In particular, glyco-alkaloids contents in potatoes are potentially toxic and secondary metabolites such as α-solanine and α-chaconine are reported to be dangerous to human health. This paper describes new methods for α-solanine and α-chaconine reduction in the potato cultivar known as Marabel. The potatoes were incubated at room temperature in the dark for 24 h and the optimal experimental condition was achieved with NaOH solution at pH 12. In the assayed samples, α-solanine and α-chaconine reduction was 43% and 27% respectively. The process proposed here allows to minimize the total content of glyco-alkaloids, with respect to mode of collection, storage and cleaning of Marabel potatoes.

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.

Polyphenols are active compounds of the medicinal plants widely distributed in nature. Despite the few and common biosynthetic origins, polyphenols encompass many subclasses of structurally different entities with a variety of pharmacological properties. Many studies suggest that the mechanisms by which plant polyphenols exert their protective actions against various diseases, are in part due to their redox properties.1Silibinin belongs to flavonolignan class, it is a major component of the Silymarin complex extracted from the milk thistle (Silybum marianum). Silibinin has long been studied for its large variety of pharmacological properties ranging from the antioxidant activity to neuroprotective and antiviral activities. In order to expand the repertoire of the modified Silibinins with high molecular diversity and good water solubility, here, we present a new and efficient method for the synthesis of dimers and trimers of the Silibinin, in which the monomer units are linked by phosphodiester bond Exploiting the selective protection of the Silibinin hydroxyl groups, we carried out a new synthetic approach using the well-established phosphoramidite chemistry. Aiming at the discovery of new pharmacological activities of these molecules, the water solubility, the radical scavenger activity by DPPH test, as well as, their ability to scavenge different reactive oxygen species (1O2 and HO●) have been studied. Additionally, the serum stability and cytoprotective behaviour (X/XO assay on HepG2 cells) of dimers have been evaluated. The combination of both striking antioxidant ability and high water solubility, makes these molecules, promising synthetic metabolites for future therapeutic applications.

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.

Two new compounds (1, 2) and 16 apocarotenoids (3-18) were isolated from the weed Chenopodium album. The structures of new apocarotenoids were determined to be (3R,6R,7E,9E,11E)-3-hydroxy-13-apo-alpha-caroten-13-one (1) and (6S,7E,9E,11E)-3-oxo-13-apo-alpha-caroten-13-one (2) by spectroscopic, NMR, and MS analysis. Five of the known compounds (5, 6, 13, 15, and 17) were previously reported only as synthetic compounds. Effects of these compounds on germination and growth of Lactuca sativa (lettuce) were studied in the 10(-4)-10(-7) M concentration range.

Gymnema sylvestre R. Br. is one of the most important medicinal plants that grows in tropical forests in India and South East Asia. Its active ingredients and extracts of leaves and roots are used in traditional medicine to treat various ailments and they are present in the market for pharmaceutical and parapharmaceutical products. Commercial products based on substances of plant origin that are generally connoted as natural have to be subjected to monitoring and evaluation by health authorities for their potential impacts on public health. The monitoring and evaluation of these products are critical because the boundary between a therapeutic action and a functional or healthy activity has not yet been defined in a clear and unambiguous way. Therefore, these products are considered borderline products, and they require careful and rigorous studies, in order to use them as complement and/or even replacement of synthetic drugs that are characterized by side effects and high economic costs. This review explores the traditional uses, chemical composition and biological activity of G. sylvestre extracts, providing a general framework on the most interesting extracts and what are the necessary studies for a complete definition of the range of activities.

In the literature there are hundreds of articles, the first dating back to 1866 and the last to 2014, on gymnemic acid, isolated from Gymnnema 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.

A new and preparative oxidation of silibinin has been developed to give access to two different silibinin derivatives known for their enhanced antioxidant properties. Conventional heating methods were compared with results obtained from microwave (MW) heating. The base-catalysed oxidation of silibinin under MW heating is a very efficient method for the preparation of 2,3-dehydrosilybin and a related silybin rearrangement product. This latter compound shows enhanced radical scavenging properties. Optimised conditions were used to prepare 2,3-dehydrosilybins A and B from optically pure silybins A and B. An efficient, preparative purification method was also developed to enable isolation of different products in high purity. (C) 2013 Elsevier Ltd. All rights reserved.

Rat thyroid cells (FRTL5), transfected with thc sequence coding for rat insulin-like growth factor II (IGF-II) presented mRNA specific for the transfected IGF-II in most of the clones obtained (Tr clones). Tr7 and Tr12 cells maintained their ability to respond to thc mitogenic effect of thyrotropin (TSH), while either exogenous IGF-I or IGF-II or insulin failed to stimulate their proliferation. In the absence of exogenous mitogens the Tr7 and Tr12 clones vigorously incorporated [H-3]thymidine into DNA. This activity was significantly inhibited by sm1.2, a monoclonal antibody against rat IGF-II. Tr7 and Tr12 clones possess type I IGF receptors, known to mediate the mitogenic effect of IGF-II, with affinity similar to those present on the membrane of the parental cells but with reduced capacity. Finally, media conditioned by Tr7 and Tr12 increase basal thymidine incorporation in quiescent FRTRL5 cells and amplify that induced by TSH. Endogenous IGFs may play an important role in the regulation of thyroid cell proliferation by modulating the mitogenic effect of TSH and by supporting TSH-independent growth.

Investigation of the organic extract of Aptenia cordifolia leaves revealed six new oxyneolignans named apteniols A–F. The structures were determined by means of spectroscopic methods. The C6C3 units are linked by an oxygen atom at C4–C4′ or C4–C2′ and they are dihydrophenylpropanoid acid units. Their effects on germination and growth of Lactuca sativa L. have been studied in the range concentration 10−4–10−7 M.

Seven cinnamic acid amides have been isolated from Chenopodium album. The structures have been attributed by means of their spectral data. One of them, N-trans-4-O-methylferuloyl 4'-O-methyldopamine, is described for the first time. Their effects on germination and growth of dicotyledons Lactuca sativa L. (lettuce) and Lycopersicon esculentum L. (tomato) and of monocotyledon Allium cepa L. (onion) as standard target species have been studied in the range concentration 10(-4)-10(-7) M.