Stanisław Ryng

Immunomodulating action and structure-activity relationships of substituted phenylamides of 5-amino-3-methylisoxazole-4-carboxylic acid.

A series of 5‐amino‐3‐methylisoxazole‐4‐carboxylic acid amides has been prepared by condensation of 5‐amino‐3‐methylisoxazole‐4‐carboxylic acid with ethyl chloroformate. The resulting mixed anhydride undergoes condensation with appropriate phenylamides to form the corresponding amides 6‐16. The compounds obtained were evaluated for their immunological activities in cultures of human peripheral blood mononuclear cells (PMBC). We found that the activities of the compounds in the proliferation test and in the lipopolysaccharide (LPS)‐induced cytokine production in PBMC cultures were differential. The stimulatory or inhibitory effects depended strongly on the origin and location of substituents in the phenyl ring which is described in the discussion and was supported by QSAR studies.

The isoxazole heterocyclic system: synthesis of a new model structure in immunosuppressing agents

AbstractA new lead structure in the isoxazole heterocyclic system showing immunosuppressing activity is described. Synthesis, spectral and X-ray data giving evidence of the structures of these compounds are presented. X-ray studies were carried out on compounds I C18H22N4O4 with a = 9.606(3), b = 9.813(3), c = 9.849(3)Å, α = 87.28(3), β = 79.06(3). γ = 80.89(3)° Z = 2, and space group

Restoration of immune system function is accelerated in immunocompromised mice by the B-cell-tropic isoxazole R-11

P\bar 1

The effect of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide on lymphocyte subsets and humoral immune response in SRBC-immunized mice

; and II C14H15N4O3Cl with a = 7.090(3), b = 16.807(3), c = 12.925(3)Å, β = 104.41(3)°, Z = 4 and space group P21/n.

DFT study of a novel lead structure in the isoxazole heterocyclic system

Abstract We describe a convenient and general method for preparation of 5-amino-3-methyl-4-isoxazolecarboxylic acid amides and hydrazides from 5-amino-3-methyl-4-isoxazolecarboxylic acid azide. In this reaction, the acyl azide reacts with amines without Curtius rearrangement.

Synthesis and X-ray structure of new 5-amino-methyl-4-isoxazolecarboxylic acid azides

BACKGROUND Restoration of impaired immune response in immunocompromised patients is a crucial problem. In this study we evaluated the efficacy of isoxazole R-11 in reconstitution of the immune response in immunosuppressed mice. METHODS Mice were given a sublethal dose (250 mg/kg b.w.) of cyclophosphamide (CP). The cellular immune response to ovalbumin (OVA) and the humoral immune response to sheep erythrocytes (SRBC) were generated. R-11 was administered at repetitive, intraperitoneal doses (20 μg/mouse) until determination of the immune responses: 7 and 15 doses on alternate days for cellular and humoral immune response, respectively. For phenotypic studies R-11 was given per os, at a single dose of 20 μg/mouse. The ability of R-11 to affect interleukin- 6 (IL-6) production was determined in the whole human blood cell culture. RESULTS R-11 increased the content of CD19+ cells in the spleens and lymph nodes with a concomitant decrease of CD3+ and CD4+ cells. The compound significantly accelerated restoration of both cellular and humoral immune responses, elevated the numbers of circulating leukocytes and splenocytes and normalized the blood cell picture. Supplementary experiments showed that R-11 was not toxic with regard to human peripheral blood mononuclear cells (PBMC) and that it upregulated IL-6 production in blood cell culture stimulated with lipopolysaccharide (LPS). CONCLUSIONS We demonstrated that R-11 is likely a B-cell tropic agent which can restore both cellular and humoral immune responses in immunocompromised mice and may have a potential to be applied in therapy of immunocompromised patients.

Anti-inflammatory properties of an isoxazole derivative – MZO-2

Abstract The aim of this study was to determine the immunomodulatory activity of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide in vitro. This compound was used for the synthesis of a series of 5-amino-3-methyl-4-isoxazolecarboxylic acid semicarbazides and thiosemicarbazides with documented immunotropic activity. The performed measurements assessed the cytotoxic effect of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide on the murine macrophages (cell line J774E.1) and lymphoblasts (cell line D10.G4.1), the influence of this compound on the proliferation of murine lymphocytes isolated from peripheral lymphatic organs and murine peritoneal macrophages stimulated with mitogens (concanavalin A(ConA), lipopolysaccharide (LPS), phytohemagglutinin A (PHA)). Moreover, the production of tumor necrosis factor (TNF)-α and interleukin (IL)-1β by the murine peritoneal macrophages stimulated with LPS from Escherichia coli was assessed. It was found that 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide displayed no cytotoxic effects in the murine J774E.1 and D10.G4.1 cell lines in a wide range of concentrations (0.5–200 μg/ml). Furthermore, the compound stimulated proliferation of lymphocytes isolated from the spleen and mesenteric lymph nodes when used alone and in combination with mitogens (ConA and PHA). This effect was stronger in the nonstimulated cells, and it followed a dose–response relationship. The same phenomenon was observed for the proliferation of the murine peritoneal macrophages. The investigated hydrazide, at the highest used concentration of 150 μg/ml, increased the LPS-induced production of IL-1β and did not affect the level of TNF-α. These results confirmed the immunomodulatory properties of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide and indicated that this compound could be useful in further research aimed at finding novel functional drugs.

Immune function in cyclophosphamide-treated mice is restored by the T-cell-tropic isoxazole derivative R-13

Abstract 5-Amino-3-methyl-4-isoxazolecarboxylic acid hydrazide is a non-cytotoxic synthetic isoxazole derivative with considerable immunomodulatory properties demonstrated in in vitro experiments. The aim of this study was to investigate the influence of this compound, depending on the dosage and schedule of treatment, on lymphocyte subsets in non-immunized mice and humoral immune response in SRBC (sheep red blood cells)-immunized mice. An analysis of lymphocyte subsets was carried out by flow cytometry, using specific monoclonal antibodies stained with fluorescein isothiocyanate (FITC) or phycoerythrin (PE). In the SRBC-immunized mice, the influence of the compound on the humoral response was determined, depending on the time of administration relative to the antigen. The number of plaque forming cells (PFC) was determined by a local hemolysis technique in an agar gel. Total and 2-mercaptoethanol resistant serum agglutination titers were defined by active hemagglutination test carried out on microplates. The investigated hydrazide was able to modulate the percentage and absolute number of T lymphocyte subsets in the thymus, and T and B lymphocytes in the peripheral lymphatic organs. It also enhanced humoral immune response in SRBC-immunized mice by increasing the number of cells producing hemolytic anti-SRBC antibodies (PFC) and by augmenting the level of total and 2-mercaptoethanol resistant hemagglutinin. The present study showed modulatory effects of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide on lymphocyte subsets and humoral immune response in mice. This compound could be potentially useful for the treatment of autoimmune diseases, infections or as an adjuvant for boosting the efficacy of vaccines.