scholarly journals Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

2017 ◽  
Vol 13 ◽  
pp. 2138-2145 ◽  
Author(s):  
Joana M Pais ◽  
Maria João Barroca ◽  
Maria Paula M Marques ◽  
Filipe A Almeida Paz ◽  
Susana S Braga
Keyword(s):  
Inclusion Compound ◽  
Antioxidant Properties ◽  
Physicochemical Analysis ◽  
Water Soluble ◽  
Solid Inclusion ◽  
Human Consumption ◽  
X Ray Diffraction ◽  
Wide Range ◽  
Soluble Solid ◽  
Cp Mas Nmr

Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host–guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

scholarly journals Antioxidant Properties of Fullerene Derivatives Depend on Their Chemical Structure: A Study of Two Fullerene Derivatives on HELFs

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Vasilina Sergeeva ◽  
Olga Kraevaya ◽  
Elizaveta Ershova ◽  
Larisa Kameneva ◽  
Elena Malinovskaya ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Chemical Structure ◽  
Antioxidant Properties ◽  
Water Soluble ◽  
Lung Fibroblasts ◽  
Human Embryonic Lung ◽  
Fullerene Derivatives ◽  
The Past ◽  
Wide Range ◽  
Short Times

Oxidative stress is a major issue in a wide number of pathologies (neurodegenerative, cardiovascular, immune diseases, and cancer). Because of this, the search for new antioxidants is an important issue. One of the potential antioxidants that has been enthusiastically discussed in the past twenty years is fullerene and its derivatives. Although in aqueous solutions fullerene derivatives have shown to be antioxidants, their properties in this regard within the cells are controversially discussed. We have studied two different water-soluble fullerene C60 and C70 derivatives on human embryonic lung fibroblasts at a wide range of concentrations. Both of them cause a decrease in cellular ROS at short times of incubation (1 hour). Their prolonged action, however, is fundamentally different: derivative GI-761 causes secondary oxidative stress whereas derivative VI-419-P3K keeps ROS levels under control values. To gain a better understanding of this effect, we assessed factors that could play a role in the response of cells to fullerene derivatives. Increased ROS production occurred due to NOX4 upregulation by GI-761. Derivative VI-419-P3K activated the transcription of antioxidant master regulator NRF2 and caused its translocation to the nucleus. This data suggests that the antioxidant effect of fullerene derivatives depends on their chemical structure.

scholarly journals Cyclodextrin-Efavirenz Complexes Investigated by Solid State and Solubility Studies

Proceedings ◽  
2020 ◽  
Vol 78 (1) ◽  
pp. 15
Author(s):  
Susana Santos Braga ◽  
Karyna Lysenko ◽  
Firas El-Saleh ◽  
Filipe A. Almeida Paz
Keyword(s):  
Solid State ◽  
Transcriptase Inhibitor ◽  
Water Soluble ◽  
Short Paper ◽  
Solid Inclusion ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Co Precipitation ◽  
Reverse Transcriptase Inhibitor

This short paper investigates the solubilizing ability of various cyclodextrins with efavirenz as well as the formation of solid inclusion complexes of efavirenz with β-CD and γ-CD. (1) Background: Efavirenz is a non-nucleoside reverse transcriptase inhibitor used as first-line treatment for adult and pediatric human immunodeficiency virus type 1 infection (HIV-1). Belonging to class II of Biopharmaceutical Classification System (BCS), efavirenz is poorly water-soluble. Inclusion into cyclodextrins is a possible strategy for increasing its solubility. (2) Methods: Solubility modulation was investigated by the phase solubility method; inclusion of efavirenz with β- and γ-cyclodextrins was attempted by co-dissolution with co-precipitation; the precipitates were studied by DSC, FT-IR, powder X-ray diffraction and optical microscopy. (3) Results: Solid state analysis of the precipitates shows evidence of separate recrystallization of β-cyclodextrin and efavirenz, whereas in the case of γ-cyclodextrin, a single new phase was observed. (4) Conclusion: Results show that the cavity of β-cyclodextrin is too narrow to accommodate efavirenz and only γ-cyclodextrin, the largest of native cyclodextrins, is able to form a true inclusion complex with this bulky guest.

scholarly journals Inclusion Compound of Efavirenz and γ-Cyclodextrin: Solid State Studies and Effect on Solubility

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 519
Author(s):  
Susana Santos Braga ◽  
Firas El-Saleh ◽  
Karyna Lysenko ◽  
Filipe A. Almeida Paz
Keyword(s):  
Solid State ◽  
Inclusion Compound ◽  
Aqueous Solubility ◽  
Variation Method ◽  
Solid Inclusion ◽  
Antiretroviral Drug ◽  
Immunodeficiency Virus ◽  
Ft Ir ◽  
Cp Mas Nmr

Efavirenz is an antiretroviral drug of widespread use in the management of infections with human immunodeficiency virus type 1 (HIV-1). Efavirenz is also used in paediatrics, but due to its very poor aqueous solubility the liquid formulations available resort to oil-based excipients. In this report we describe the interaction of γ-cyclodextrin with efavirenz in solution and in the solid state. In aqueous solution, the preferential host–guest stoichiometry was determined by the continuous variation method using 1H NMR, which indicated a 3:2 host-to-guest proportion. Following, the solid inclusion compound was prepared at different stoichiometries by co-dissolution and freeze-drying. Solid-state characterisation of the products using FT-IR, 13C{1H} CP-MAS NMR, thermogravimetry, and X-ray powder diffraction has confirmed that the 3:2 stoichiometry is the adequate starting condition to isolate a solid inclusion compound in the pure form. The effect of γ-cyclodextrin on the solubility of efavirenz is studied by the isotherm method.

C-H bond Activation/Arylation over Arene-Ruthenium(II)-picolinate Complexes: Synthesis, Structure and Catalytic Activity

2017 ◽  
Author(s):  
Chinky Binnani ◽  
Rohit K. Rai ◽  
Deepika Tyagi ◽  
Shaikh M Mobin ◽  
Sanjay Kumar Singh
Keyword(s):  
Catalytic Activity ◽  
Bond Activation ◽  
Ruthenium Catalysts ◽  
Molecular Structures ◽  
Water Soluble ◽  
Aryl Halides ◽  
Donor Ligands ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Wide Range

<p>A series of water soluble arene-ruthenium(II) complexes [(<i>η</i><sup>6</sup>-arene)RuCl(κ<sup>2</sup>-L)]<sup>n+</sup> (n = 0, 1) (<b>[Ru]-1</b> – <b>[Ru]-12</b>) containing pyridine based N,O or N,N ligands (<b>L1-L6</b>) were synthesized and employed for the catalytic C-H bond activation/ arylation of 2-phenylpyridine with aryl halides in water. Efficient C-H bond activation/ arylation of a wide range of substituted 2-phenylpyridines and aryl halides were achieved to afford corresponding mono and biarylated products. Exploring the reactivity of the synthesized complexes, our investigation with ruthenium catalysts inferred that pyridine based N,O donor ligands afforded enhanced catalytic activity compared to those obtained with the iminopyridine (N,N donor) ligands. Further, mass spectrometric investigations, during the catalytic and controlled reaction conditions, evidenced the presence of the crucial cycloruthenated species {(<i>η</i><sup>6</sup>-<i>p</i>-cymene)Ru(<i>κ</i><sup>2</sup>-<i>CN</i>-phenylpyridine)}<sup>+</sup> (m/z [M<sup>+</sup>] 390.0), along with a ligand coordinated species, {(<i>η</i><sup>6</sup>-<i>p</i>-cymene)Ru(<b>L1</b>)(<i>κ</i><sup>2</sup>-<i>CN</i>-phenylpyridine)}<sup>+</sup> (m/z [M<sup>+</sup>]+Na 539.0), suggesting the important role such intermediate species in C-H bond activation reactions. Moreover, molecular structures for few of the representative complexes were also authenticated by single crystal X-ray diffraction studies.</p>

scholarly journals Structure Analysis and Antioxidant Activity of a Novel Polysaccharide from Katan Seeds

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Imen Trabelsi ◽  
Sirine Ben Slima ◽  
Naourez Ktari ◽  
Mohamed Bouaziz ◽  
Riadh Ben Salah
Keyword(s):  
High Performance ◽  
Antioxidant Properties ◽  
Water Soluble ◽  
Uv Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
1H Nuclear Magnetic Resonance ◽  
Soluble Polysaccharide ◽  
Promising Source ◽  
Layer Chromatography

In the present work, a novel water-soluble polysaccharide (LWSP) was purified from Katan seeds. Polysaccharide was structurally characterized by NMR spectroscopic analysis, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FTIR) analysis, X-ray diffraction (XRD), and UV absorption. TLC and HPLC showed that LWSP was a polysaccharide consisted mainly of glucose, mannose, xylose, and arabinose. The FTIR spectrum and UV absorption proved polysaccharide characteristic of LWSP. According to XRD, LWSP presented a semicrystalline behavior. The molecular weight was estimated as 64.56 kDa. Results obtained through 13C and 1H nuclear magnetic resonance (NMR) indicated that LWSP is consisted of four monosaccharide residues with α and β anomers. Physicochemical and antioxidant properties of LWSP were also investigated. Results revealed that LWSP exhibited interesting 1,1-diphenyl-2-picrylhydrazyl (DPPH) ( I C 50 = 4.48  mg/ml) and chelating activity ( I C 50 = 4.79  mg/ml), and it displayed moderate reductive capacities. Overall, the findings suggested that LWSP is a promising source of natural additives in various industries fields.

scholarly journals Absolute Configuration of Mycosporine-Like Amino Acids, Their Wound Healing Properties and In Vitro Anti-Aging Effects

Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 35 ◽  
Author(s):  
Maria Orfanoudaki ◽  
Anja Hartmann ◽  
Mostafa Alilou ◽  
Thomas Gelbrich ◽  
Patricia Planchenault ◽  
...  
Keyword(s):  
Amino Acids ◽  
Wound Healing ◽  
Absolute Configuration ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Aging Effects ◽  
Wide Range ◽  
Glycation End Products ◽  
Collagenase Inhibition

Mycosporine-like amino acids (MAAs) are water-soluble metabolites, reported to exhibit strong UV-absorbing properties. They have been found in a wide range of marine organisms, especially those that are exposed to extreme levels of sunlight, to protect them against solar radiation. In the present study, the absolute configuration of 14 mycosporine-like-amino acids was determined by combining the results of electronic circular dichroism (ECD) experiments and that of advanced Marfey’s method using LC-MS. The crystal structure of a shinorine hydrate was determined from single crystal X-ray diffraction data and its absolute configuration was established from anomalous-dispersion effects. Furthermore, the anti-aging and wound-healing properties of these metabolites were evaluated in three different assays namely the inhibition of collagenase, inhibition of advanced glycation end products (AGEs) and wound healing assay (scratch assay).

C-H bond Activation/Arylation over Arene-Ruthenium(II)-picolinate Complexes: Synthesis, Structure and Catalytic Activity

2017 ◽  
Author(s):  
Chinky Binnani ◽  
Rohit K. Rai ◽  
Deepika Tyagi ◽  
Shaikh M Mobin ◽  
Sanjay Kumar Singh
Keyword(s):  
Catalytic Activity ◽  
Bond Activation ◽  
Ruthenium Catalysts ◽  
Molecular Structures ◽  
Water Soluble ◽  
Aryl Halides ◽  
Donor Ligands ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Wide Range

<p>A series of water soluble arene-ruthenium(II) complexes [(<i>η</i><sup>6</sup>-arene)RuCl(κ<sup>2</sup>-L)]<sup>n+</sup> (n = 0, 1) (<b>[Ru]-1</b> – <b>[Ru]-12</b>) containing pyridine based N,O or N,N ligands (<b>L1-L6</b>) were synthesized and employed for the catalytic C-H bond activation/ arylation of 2-phenylpyridine with aryl halides in water. Efficient C-H bond activation/ arylation of a wide range of substituted 2-phenylpyridines and aryl halides were achieved to afford corresponding mono and biarylated products. Exploring the reactivity of the synthesized complexes, our investigation with ruthenium catalysts inferred that pyridine based N,O donor ligands afforded enhanced catalytic activity compared to those obtained with the iminopyridine (N,N donor) ligands. Further, mass spectrometric investigations, during the catalytic and controlled reaction conditions, evidenced the presence of the crucial cycloruthenated species {(<i>η</i><sup>6</sup>-<i>p</i>-cymene)Ru(<i>κ</i><sup>2</sup>-<i>CN</i>-phenylpyridine)}<sup>+</sup> (m/z [M<sup>+</sup>] 390.0), along with a ligand coordinated species, {(<i>η</i><sup>6</sup>-<i>p</i>-cymene)Ru(<b>L1</b>)(<i>κ</i><sup>2</sup>-<i>CN</i>-phenylpyridine)}<sup>+</sup> (m/z [M<sup>+</sup>]+Na 539.0), suggesting the important role such intermediate species in C-H bond activation reactions. Moreover, molecular structures for few of the representative complexes were also authenticated by single crystal X-ray diffraction studies.</p>

scholarly journals Control of Pharmaceutical Cocrystal Polymorphism on Various Scales by Mechanochemistry: Transfer from the Laboratory Batch- to the Large-Scale Extrusion Processing

2018 ◽  
Author(s):  
Tomislav Stolar ◽  
Stipe Lukin ◽  
Martina Tireli ◽  
Irena Sović ◽  
Bahar Karadeniz ◽  
...  
Keyword(s):  
Vitamin C ◽  
Mechanochemical Synthesis ◽  
Large Scale ◽  
Antioxidant Properties ◽  
In Situ Monitoring ◽  
Human Consumption ◽  
Continuous Manufacturing ◽  
X Ray Diffraction ◽  
X Ray

<p>We demonstrate a controllable mechanochemical synthesis of cocrystal polymorphs of ascorbic acid (vitamin C) and nicotinamide (vitamin B3) on different scales and without using bulk solvents. Next to the previously described polymorph of the 1:1 cocrystal, which is one of the first cocrystals approved for human consumption, we report here a new, thermodynamically more stable polymorph detected during in situ synchrotron powder X-ray diffraction monitoring of milling reactions. The new polymorph is currently available exclusively by mechanochemical synthesis, and its crystal structure was determined from powder X-ray diffraction data. Laboratory in situ monitoring by Raman spectroscopy provided direct insight into the cocrystals formation and was further used to optimize the manufacturing procedure. Sub-gram synthesis using laboratory mixer mill was transferred to the 10 g scale on a planetary ball mill and continuous manufacturing using a twin-screw extruder. Both cocrystal polymorphs perform excellently in tableting, thus alleviating the notoriously poor compactible properties of vitamin C, while the mechanochemical cocrystallization does not harm its antioxidant properties.<b></b></p>

scholarly journals Control of Pharmaceutical Cocrystal Polymorphism on Various Scales by Mechanochemistry: Transfer from the Laboratory Batch- to the Large-Scale Extrusion Processing

2018 ◽  
Author(s):  
Tomislav Stolar ◽  
Stipe Lukin ◽  
Martina Tireli ◽  
Irena Sović ◽  
Bahar Karadeniz ◽  
...  
Keyword(s):  
Vitamin C ◽  
Mechanochemical Synthesis ◽  
Large Scale ◽  
Antioxidant Properties ◽  
In Situ Monitoring ◽  
Human Consumption ◽  
Continuous Manufacturing ◽  
X Ray Diffraction ◽  
X Ray

<p>We demonstrate a controllable mechanochemical synthesis of cocrystal polymorphs of ascorbic acid (vitamin C) and nicotinamide (vitamin B3) on different scales and without using bulk solvents. Next to the previously described polymorph of the 1:1 cocrystal, which is one of the first cocrystals approved for human consumption, we report here a new, thermodynamically more stable polymorph detected during in situ synchrotron powder X-ray diffraction monitoring of milling reactions. The new polymorph is currently available exclusively by mechanochemical synthesis, and its crystal structure was determined from powder X-ray diffraction data. Laboratory in situ monitoring by Raman spectroscopy provided direct insight into the cocrystals formation and was further used to optimize the manufacturing procedure. Sub-gram synthesis using laboratory mixer mill was transferred to the 10 g scale on a planetary ball mill and continuous manufacturing using a twin-screw extruder. Both cocrystal polymorphs perform excellently in tableting, thus alleviating the notoriously poor compactible properties of vitamin C, while the mechanochemical cocrystallization does not harm its antioxidant properties.<b></b></p>

Microsponges: An Overview

2017 ◽  
Vol 4 (4) ◽  
Author(s):  
Hamid Hussain ◽  
Divya Juyal ◽  
Archana Dhyani
Keyword(s):  
Controlled Release ◽  
Delivery System ◽  
Oral Delivery ◽  
Active Agent ◽  
Topical Delivery ◽  
Water Soluble ◽  
Wide Range ◽  
Porous Beads

Microsponge and Nanosponge delivery System was originally developed for topical delivery of drugs can also be used for controlled oral delivery of drugs using water soluble and bioerodible polymers. Microsponge delivery system (MDS) can entrap wide range of drugs and then release them onto the skin over a time by difussion mechanism to the skin. It is a unique technology for the controlled release of topical agents and consists of nano or micro porous beads loaded with active agent and also use for oral delivery of drugs using bioerodible polymers.

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