In previous communications (l-3) it has been demonstrated that the antibiotic activity (4) produced by heating n-penicillamine (II) hydrochloride hydrate with 2-benzyl-4-methoxymethylene-5(4)-oxazolone (I) in pyridine is due to the synthesis of benzylpenicillin. Because of these results there can be little doubt that, when oxazolones substituted with other groups in the 2 position are condensed...

Oxazolone (OXA) is a potent contact allergen in man, and it is used as a model Th1-allergen to test (Q)SAR's and screening assays for allergenic potential of chemicals. However, it elevates serum IgE levels and Thelper2 cytokines at relatively low doses in test animals, suggesting that it has also respiratory allergenic potential. The lack of human data on respiratory allergenic potential of OX...

A murine model of immune responsiveness had been adapted to study anergic conditions associated with neoplasia. Marked anergy observed in mice bearing L1210 leukemia and P-388 lymphoma is contrasted to the minimal immune depression associated with B-16 melanotic melanoma and Sarcoma 180J. The ability of N,N-bis(2-chloroethyl)-N-nitrosourea chemotherapy to reduce tumor burden without prolonged s...

The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S a)-Binap·AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high e...

Continuous cultures of T cells from the lymph nodes of mice sensitized to the contact sensitizers 4-ethoxymethylene-2-phenyl oxazolone or picryl chloride have been established. For continuous proliferation, the lines required specific antigen, syngeneic antigen-presenting cells, and growth factors from the supernatant of concanavalin-A-stimulated lymphoid cultures. Cells from the lines showed a...