Development of Aldehyde Hyaluronic Acid - N,O-Carboxymethyl Chitosan based Hydrogel for Intraperitoneal Antiadhesion Application

Intraperitoneal adhesion is a serious case that often occurs with a prevalence of 90-97 % after undergoing gynecological surgery and laparotomy. This study aims are to characterized the hydrogel and identified the optimal composition of Hyaluronic acid (HA) - N, O-carboxymethyl chitosan (NOCC) as an anti-adhesion biomaterial barrier. The synthesis method involved firstly the synthesis of aldehyde derivative of hyaluronic acid (AHA) and also the conversion of chitosan into its derivative, N,O-carboxymethyl chitosan. These two compounds were mixed in various compositions and crosslinked to form N, O-carboxymethyl chitosan (NOCC) /AHA. Fourier-transform infrared spectroscopy has confirmed that the functional groups found -C = O stretching at 1644 cm-1 indicating the hyaluronic acid and carboxymethyl group (-CH2COOH) in 1380 cm-1 which indicate the presence of chitosan. The crosslink is evidenced by the group C = N stretching at a wavenumber of about 1630 cm-1. The best composition of intraperitoneal anti-adhesion is the ratio of hyaluronic acid: chitosan at 30:10 mg/ml. The swelling test is showed a swelling ratio of around 211.8 % in accordance with the standard as intraperitoneal anti-adhesion. Hydrogel has a degradation rate up to 86.87 % on day 10, and this is in accordance with the standard as intraperitoneal anti-adhesion. Cytotoxicity assay showed that hydrogel was nontoxic with a percentage of 92.9 % cell viability. The newly developed hyaluronic acid-carboxymethyl chitosan has characteristics that conform to the criteria of an intraperitoneal anti-adhesion.

New Z-chalcones obtained from aloe-emodin: Synthesis, characterization and photophysical properties

Three new Z-chalcone derivatives were synthesized under stereoselective conditions by condensation between an aldehyde derivative (prepared from aloe-emodin) and an acetophenone, using potassium hydroxide in dimethyl sulfoxide/H2O at room temperature. The Z configuration of the chalcone derivatives was established by nuclear magnetic resonance (NMR) studies. Photophysical properties related to the UV-Vis absorption/emission spectra and molar extinction coefficients (ε) in different solvents were determined.

Oxidation of 5-methylaminomethyl uridine (mnm5U) by Oxone Leads to Aldonitrone Derivatives

Oxidative RNA damage is linked to cell dysfunction and diseases. The present work focuses on the in vitro oxidation of 5-methylaminomethyl uridine (mnm5U), which belongs to the numerous post-transcriptional modifications that are found in tRNA. The reaction of oxone with mnm5U in water at pH 7.5 leads to two aldonitrone derivatives. They form by two oxidation steps and one dehydration step. Therefore, the potential oxidation products of mnm5U in vivo may not be only aldonitrones, but also hydroxylamine and imine derivatives (which may be chemically more reactive). Irradiation of aldonitrone leads to unstable oxaziridine derivatives that are susceptible to isomerization to amide or to hydrolysis to aldehyde derivative.

SYNTHESIS, CHARACTERISATION, ANTIOXIDANT AND ANTICANCER EVALUATION OF NOVEL FLAVONE-4-OXIMES

A series of novel flavone-4-oximes were synthesized by the oximation of substituted flavones. The synthesized compounds were characterized by various spectrochemical methods including IR, MS and NMR spectroscopy. Out of the 14 test compounds screened for their antioxidant activity, compounds such as JGS-VI (a N,N dimethyl benzaldehyde derivative) and JGS-VII (a 3,4 dimethoxy benzaldehyde derivative) exhibited antioxidant activity comparable to that of ascorbic acid and quercetin as standards following DPPH method. Compounds such as JGS-II (a p-fluoro benzaldehyde derivative), JGS-IV (a p-methyl benzaldehyde derivative) and JGS-V (a thiophene-2-aldehyde derivative) exhibited antioxidant activity among all the test compounds screened against ABTS. However, none of them showed any significant scavenging activity against nitric oxide scavenging assay in the concentration range of 200 μM-25μM. Further, anti-cancer potency for all the test compounds were evaluated by MTT assay against two different cell lines namely MCF-7 and Hep-G2. Compounds such as JGS-I (a p-chloro benzaldehyde derivative), JGS-II (a p-fluoro benzaldehyde derivative), JGS-IV, JGS-V (a thiophene -2-aldehyde derivative), JGS-VI and JGS-IX (a 3,4 chloro benzaldehyde derivative) exhibited activity better than the rest of the test compounds tested against MCF-7 cell lines. Compounds such as JGS-VI, JGS-VII, JGS-VIII (a p-bromo benzaldehyde derivative) and JGS-IX exhibited anti-cancer activity better than other test compounds tested against Hep-G2 cell lines. Thus, a few of the synthesized test compounds could become promising anti-cancer agents.

Divergent synthesis of various iminocyclitols from d-ribose

A very efficient route to the diastereoselective synthesis of polyhydroxy pyrrolidines, piperidines and azepanes from an aldehyde derivative of ribose is reported.

Synthesis of New Hexakis-Heterocyclic Compounds and their Use in the Formation and Stabilization of Au and Ag Nanoparticles

The stabilization of nanoparticles in solution is a challenge of major proportions, and avoiding the formation of aggregates and eventual coalescence of particles is directly linked to the conservation of its unique properties. In this work, we reported the synthesis of two hexakis-heterocyclic compounds, containing the tetrazole or 2-amino-1,3,4-thiadiazole group, respectively. The hexa-heterocyclic compounds were used in the synthesis and stabilization of Au and Ag nanoparticles. To obtain these molecules was used phosphonitrilic chloride trimer compound as core, which reacted with phenols properly substituted in theparaposition with either cyano or aldehyde group. The cyano group was successfully converted to the corresponding tetrazole using a 1,3-dipolar cycloaddition reaction with ammonium azide generatedin situ. In the case of aldehyde derivative, it was converted to the corresponding thiosemicarbazone, which was further cyclized using FeCl3. Compounds were characterized by RMN and IR spectroscopy. The UV-Vis spectroscopy was used for nanoparticles analysis.