Using affinity chromatography, two-dimensional electrophoresis, and MALDI-TOF mass spectrometry, plasminogen isoforms were separated and identified in blood plasma. Healthy donors and patients with prostate cancer in various stages of development were included in the studied sample. With the development of prostate cancer, four additional specific plasminogen isoforms are registered in blood plasma; they are characterized by lower molecular weights and higher pI values compared to isoforms found in the control group.
SHORT COMMUNICATIONSReactions of pyrrolo[2,1-a]isoquinoline-2,3-diones with nitrogen-centered nucleophiles can be accompanied by opening of the pyrrole ring [1,2] or the latter may be conserved [3]. The Knoevenagel condensation of pyrrolo[2,1-a]isoquinoline-2,3-diones with cyanoacetic acid derivatives does not involve opening of the pyrrole ring [4]. The goal of the present work was to synthesize new ylidene derivatives of pyrrolo[2,1-a]-isoquinoline-2,3-diones and study their behavior as dipolarophiles.In continuation of our studies on reactions of pyrrolo[2,1-a]isoquinoline-2,3-dione (I) and its benzofused derivative II with nucleophiles, we examined their condensation with such sulfur-centered nucleophiles as N-substituted rhodanines IIIa and IIIb (Scheme 1). The reactions were carried out in methanol in the presence of a catalytic amount of 40% aqueous potassium hydroxide. The condensation was not accompanied by opening of the pyrrole ring, and the products were the corresponding thiazolidin-5-ylidenesubstituted derivatives IV and V.According to spectral data, compounds IV and V were formed exclusively as E isomers with trans orientation of the carbonyl groups in the pyrrole and thiazolidine rings. The 1 H NMR spectra of IV and V contained no signals assignable to other isomers, and the 1′-H (IV) and 10′-H (V) signals were displaced downfield (δ 7.15 and 7.28 ppm, respectively) due to deshielding effect of the C 4 =O carbonyl group in the rhodanine fragment.The newly formed double C=C bond is a good dipolarophile, so that ylidene derivatives IV and V
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