Synthesis and characterization Some of heterocyclic compounds from Nitrogen derivative

This paper involves the synthesis of new oxazepine derivatives by multi-reaction steps. The first step synthesis azo derivative from 2-naphthol with 3-aminoacetophenone. The second step was the condensation reaction between ketone group of the azo compound and different primary aromatic amines (4-amino phenol, 3-nitro aniline and 4-methyl aniline) to yiled new azo Schiff base compounds (S1-S3) respectively. In the final step, Oxazepine compounds (L1-L3)and (L4-L6)were prepared from reaction imine compounds (S1-S3) with maleic and phthalic anhydride in toluene as solvent. All these derivatives were characterized by melting point, FTIR, HNMR and 13CNMR.

Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

Canine visceral leishmaniasis: successful chemotherapy induces macrophage antileishmanial activity via the L-arginine nitric oxide pathway.

Following successful chemotherapy in canine visceral leishmaniasis, monocyte-derived macrophages can induce antileishmanial activity via a gamma interferon-dependent mechanism in the presence of autologous lymphocytes. The killing of leishmania correlated with the induction of the NO synthase pathway, because it correlated with the generation of nitrogen derivative production and was abrogated in the presence of NG-monomethyl-L-arginine, a competitive inhibitor of the NO synthase pathway. The level of L-citrulline in serum, which was produced after activation of the NO synthase pathway, was markedly enhanced in dogs receiving successful chemotherapy. Taken together, these data indicate that following successful chemotherapy of visceral leishmaniasis, leishmania parasites are killed by macrophages activated by gamma interferon-producing lymphocytes via an NO-dependent mechanism.