Search results for "CHEMICALS"
showing 10 items of 991 documents
Enantioselective sensing of dicarboxylates. Influence of the stoichiometry of the complexes on the sensing mechanism
2009
Two new cyclohexane-based thiourea chiral ligands have been synthesized in their enantiomerically pure forms. Both the ability of these ligands in the complexation of chiral dicarboxylates and their sensing properties have been studied. The influence of the stoichiometry of the formed complexes on the fluorescent properties of the systems has been established. The effect of additional substitution in the cyclohexyl moiety was considered by comparing the properties of the newly prepared ligands with those of similar compounds previously described.
Resveratrol, a chemopreventive agent, disrupts the cell cycle control of human SW480 colorectal tumor cells
2002
Resveratrol is a natural polyphenolic compound produced by a number of plants and found in high amount in peanuts, seeds, grapes or berries as source of human nutrition. Epidemiological studies strongly suggest that resveratrol may act as a cancer chemopreventive compound. The mechanism by which resveratrol inhibits cell proliferation was studied in human colorectal tumor SW480 cell line. The results show that resveratrol strongly inhibits cell proliferation at the micromolar range in a time- and dose-dependent manner. Resveratrol appears to block the cell cycle at the transition --> G2/M since inhibition of [(3)H]-thymidine incorporation is not observed, while there is an increase of the c…
Phytochemical Constituents, Antioxidant Activity, and Toxicity Assessment of the Aerial Part Extracts from the Infraspecific Taxa of Matthiola frutic…
2021
In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC–PDA/ESI–MS and SPME–GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative–quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe2+ chelating activ…
Phytochemical profile and bioactivity of traditional ayurvedic decoctions and hydro-alcoholic macerations of Boerhaavia diffusa L. and Curculigo orch…
2015
Decoctions (DECs) and hydro-alcoholic extracts (HEs) prepared from roots of Boerhaavia diffusa L. (Nyctaginaceae) and Curculigo orchioides Gaertn. (Hypoxidaceae) were phytochemically characterised by HPLC-DAD and profiled for their antioxidant, antigenotoxic and cytotoxic activities. B. diffusa DEC was rich in ferulic acid and vanillin, while the HE also contained boeravinone B and eupalitin. Both C. orchioides HE and DEC displayed the main occurrence of orcinol-β-d-glucoside and curculigoside A. Antioxidant activity was assayed through spectrophotometric DPPH, ABTS and β-carotene bleaching test, and using (HP)TLC bioautographic strategies. For both crude drugs, HE was the best performing p…
Development of stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles and its analytical application to the determination of…
2014
A novel microextraction technique combining the principles of stir bar sorptive extraction (SBSE) and dispersive micro-solid phase extraction (DμSPE) is presented. The main feature of the method is the use of a neodymium-core stirring bar physically coated with a hydrophobic magnetic nanosorbent. Depending on stirring speed, the magnetic sorbent either acts as a coating material to the stir bar, thus affording extraction alike SBSE, or as a dispersed nanosorbent medium for the collection and extraction of the target analytes, in close analogy to DμSPE. Once the stirring process is finished, the strong magnetic field of the stir bar prevails again and rapidly retrieves the dispersed MNPs. Al…
Anisotropic lattice distortions in biogenic calcite induced by intra-crystalline organic molecules.
2006
9 pages; International audience; We have performed precise structural measurements on five different calcitic seashells by high-resolution X-ray powder diffraction on a synchrotron beam line and by laboratory single crystal X-ray diffraction. The unit cell parameters a and c of biogenic calcite were found to be systematically larger than those measured in the non-biogenic calcite. The maximum lattice distortion (about 2.10(-3)) was detected along the c-axis. Under heat treatment above 200 degrees C, a pronounced lattice relaxation was observed, which allowed us to conclude that anisotropic lattice swelling in biogenic calcite is induced by organic macromolecules incorporated within the sing…
The ethnobotany, phytochemistry, and biological properties of Nigella damascena – A review
2022
This review is a systematic scientific work on medicinal and traditional use, on the chemical composition of specialized metabolites, volatile and non-volatile, on aspects related to toxicology and phytotherapy of Nigella damascena L. The genus Nigella (Ranunculaceae) is distributed throughout the Mediterranean basin, extending to northern India, and has been divided into three sections. Nigella damanscena L. is traditionally used as an ingredient in food, for example, as flavouring agents in bread and cheese, but is also known in folk medicine, used to regulate menstruation; for catarrhal affections and amenorrhea; as a diuretic and sternutatory; as an analgesic, anti-oedematous, and antip…
Unraveling the interaction between doxorubicin and DNA origami nanostructures for customizable chemotherapeutic drug release
2021
We thank Dr H. Häkkänen for technical assistance and S. Julin for the 24HB DNA origami design. We acknowledge the provision of facilities and technical support by Aalto University Bioeconomy Facilities and OtaNano – Nanomicroscopy Center (Aalto-NMC). The research was carried out under the Academy of Finland Centres of Excellence Programme (2014–2019). Academy of Finland [308578 to M.A.K.]; Deutsche Forschungsgemeinschaft [Emmy Noether Programme to A.H.-J., SFB1032 (Project A06) to T.L.]; Emil Aaltonen Foundation [to H.I. and V.L.]; Jane and Aatos Erkko Foundation [to J.A.I. and V.L.]; Sigrid Jusélius Foundation [to V.L.]; Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Sc…
PLGA nanoparticles are effective to control the colonic release and absorption on ibuprofen.
2018
The oral controlled release (CR) formulations have become more important in recent years. Among them, the polymeric nanoparticles have been thoroughly studied during the last decades, consequently they are extensively employed for a broad range of applications and drugs. The objective of this research was to develop polymeric nanoparticles (NPs) of ibuprofen with poly(lactic-co-glycolic) acid (PLGA) as polymer, and to test their applicability for oral CR formulations development. Different proportions of drug/polymer were employed to develop the ibuprofen NPs and their in vitro release profiles were analysed. The in situ segmental permeability of ibuprofen was tested in Wistar rat and demon…
Selected Secondary Plant Metabolites for Cancer Therapy
2015
Secondary plant metabolites reveal numerous biological activities making them attractive as resource for drug development of human diseases. As the majority of cancer drugs clinically established during the past half century is derived from nature, cancer researchers worldwide try to identify novel natural products as lead compounds for cancer therapy. Natural products are considered as promising cancer therapeutics, either as single agents or in combination protocols, to enhance the antitumor activity of additional therapeutic modalities. Most natural compounds exert pleotrophic effects and modulate various signal transduction pathways. A better understanding of the complex mechanisms of a…