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Protein sulfhydryl reactive N-(4-[125I]iodophenethyl)maleimide (IPEM, 5) was obtained from N-[4-(tri-n-butylstannyl)phenethyl]maleimide in 59-100% radiochemical yield. Conjugation of 5 to NR-ML-05 Fab, a murine anti-melanoma antibody Fab fragment that had been previously reduced with dithiothreitol (DTT), was effected in an average of 85% yield. Results from in vitro chemical challenges and serum stability studies on the IPEM conjugate of NR-ML-05 Fab (6) indicated a stable covalent attachment of the radioiodine. A biodistribution study of the IPEM conjugate in tumor-bearing athymic nude mice showed lack of significant accumulation of radioiodine in the thyroid and stomach which was an indication of in vivo stability. The observed uptake in tumor was consistent with that obtained for Chloramine-T- or p-iodobenzoate-labeled NR-ML-05 Fab conjugates.

Astatine-211 labeling of an antimelanoma antibody, NR-ML-05, and its Fab fragment with N-succinimidyl p-[211At]astatobenzoate (2a) has been described. Preparation of the astatinated intermediate 2a was accomplished by distilling astatine-211 from an irradiated bismuth target directly into a reaction mixture containing an organometallic compound, N-succinimidyl p-(tri-n-butylstannyl)benzoate (1), and an oxidant, N-chlorosuccinimide, in 5% HOAc/MeOH. Trapping of distilled astatine as 2a was found to be efficient, resulting in 70-90% yields based on the amount of astatine-211 in the reaction mixture. The dry distillation technique employed gave recoveries of astatine-211 which ranged from 20% to 75%. Conjugation of 2a to NR-ML-05 and its Fab fragment was accomplished in 40-60% yields. The [211At]astatobenzoyl-conjugated antibodies were found to be stable in vitro when challenged by strong denaturants and nucleophilic reagents. Coinjected dual-labeled studies of the 2a astatinated antibodies and the same antibodies labeled with N-succinimidyl p-[125I]iodobenzoate (2b) in athymic mice bearing the human tumor xenograft A375 Met/Mix demonstrated that both radiolabeled antibodies had equivalent tumor localization. Data from the dual-labeled biodistribution of the intact antibody suggests that the astatine is stably attached. Data from the dual-labeled Fab fragment suggests that a portion of the astatine label is released as astatide, either from the astatinated Fab or from a catabolite.

A comparative investigation of the biodistributions of radioiodinated p- and m-iodobenzoyl conjugates of a monoclonal antibody Fab fragment, NR-LU-10 Fab, and the same antibody Fab fragment radioiodinated by the chloramine-T (ChT) method has been carried out in mice. Coinjected, dual-isotope studies in athymic mice with tumor xenografts have demonstrated that there are only minor differences in the in vivo distributions of the iodobenzoyl-labeled Fabs, except in the excretory organs, kidneys, and intestines, where major differences were observed. Similarly, coinjection of either the p-iodobenzoyl or m-iodobenzoyl conjugate of NR-LU-10 Fab with the Fab radioiodinated with ChT/radioiodide into BALB/c mice provided additional data that indicated that the two iodobenzoyl conjugates distributed similar in a number of selected tissues. The tissue-distribution differences of the regioisomeric iodobenzoyl conjugates in relation to the ChT-radioiodinated Fab were large for the stomach and neck, consistent with previous studies. The most notable difference between the two iodobenzoyl conjugates was the kidney activity, where the m-iodobenzoyl conjugate was similar to the directly labeled Fab, but the p-iodobenzoyl-conjugated Fab was higher by nearly a factor of 2.

A confirmation procedure is described for detection of residues of six tetracyclines in bovine milk, and oxytetracycline in shrimp. Residues are extracted from milk or shrimp tissue using metal chelate affinity chromatography. The extracts are desalted, further concentrated using polymeric solid-phase extraction, and chromatographed on a polymeric reversed-phase column. Analysis is by methane negative ion chemical ionization on a quadrupole mass spectrometer using a particle beam interface. Data are acquired in partial scan mode, monitoring from m/z 378 to m/z 480. The procedure was validated with control milk and shrimp, fortified milk (30 ng/ml) and shrimp (100 ng/g), and milk and tissue from animals treated with the drugs.

A monoclonal antibody against the murine T-cell antigen Thy 1.1 was radioiodinated using N -succin-imidyl p -iodobenzoate (PIP) in an attempt to decrease deiodination of the labeled antibody. The biodistribution of the PIP labeled antibody was compared to Iodogen labeled antibody in Thy 1.1 + lymphoma bearing AKR/Cum mice, where the antibody was tumor specific, and AKR/J mice where the antibody reacted with both tumor and normal T-cells. PIP labeling resulted in decreased iodine concentrations in stomach and salivary gland as compared to Iodogen labeling. There was little difference in radioiodine concentrations between the two preparations in tumor, lymphoid tissues or other organs. These results suggest deiodination of intact antibody plays little role in the clearance of radioiodinated anti-Thy 1.1 antibody from tissues.

Vinyl radiohalogenated small molecules as shown in formulas I and II: ##STR1## wherein *X is a radiohalogen, C═C is a double bonded set of sp2 hybridized carbon atoms, and substituents R1, R2, and Y are as defined below. R1 and R2 are substituents independently selected from among hydrogen; alkyl or substituted alkyl, provided that any sp2 or sp carbon atom substituted on the alkyl is separated from C═C by at least one fully substituted sp3 carbon atom; aryl or substituted aryl, provided that the aryl is bonded directly to C═C; heteroalkyl, provided, first, that no heteroatom of the heteroalkyl bonds directly to C═C and, second, that any sp2 or sp hybridized carbon bonded to a heteroatom of the heteroalkyl is not bonded directly to or otherwise conjugated with C═C and, third, that where a single sp3 carbon intervenes between C═C and an sp2 or sp carbon bonded to a heteroatom that intervening sp3 carbon must be fully substituted; heteroaryl, provided that a heteroatom of the heteroaryl is not bonded directly with C 50 C; mixed alkylaryl, provided first, that no heteroatom is bonded to C═C and, second that either an aryl moiety of the mixed alkylaryl is directly bonded to C═C or that any aryl moiety is separated from C═C by at least one sp3 carbon atom and, where only one sp3 hybridized carbon atom intervenes between C═C and an aryl moiety, that intervening sp3 carbon must be fully substituted. Y is substituent containing any of the groups described above for R1 and R2, except that Y cannot be hydrogen, and bearing a functional group suitable for binding to protein under conditions that preserve the biological activity of the protein. The compounds of formulas I and II can be coupled to proteins such as monoclonal antibodies ot provide reagents for diagnostic and therapeutic applications. Also metalated precursors of compounds I and II, as well as radiophormaceutical reagent kits containing any of the subject small molecules.

The development of monoclonal antibodies of high affinity and selectivity for tumor antigens has supported the development of radiolabeled antibodies for diagnostic localization and targeted delivery of therapeutic radionuclides. Several radionuclide chelating agent systems have been developed for indium-111 and technetium-99m that have shown good sensitivity and specificity for tumor detection in patients. Feasibility for therapy has been shown in animal models and a few patient studies with iodine-131 and yttrium-90. This review covers selection of radionuclides and chemistry of antibody radiolabeling.

Synthesis of methyl 4-tri-n-butylstannylbenzoate (1) was accomplished by reaction of methyl 4-bromobenzoate with hexabutylditin and palladium catalyst. Transmetallation of 1 with mercuric acetate yielded the corresponding arylmercuric acetate 4 which was readily converted to aryl mercuric halides 2a and 2b. Reaction of arylmercuric bromide 2b with diborane or catecholborane produced arylboronic acid 3 in high yield. Iodinations of 1. 2a and 3 were studied using N-chlorosuccinimide/NaI at the 10% and 100% stoichiometric amounts of NaI with Na125I added to monitor the course of the reaction.

Quatre catalyseurs (Me 2 AlCl=SnCl 4 >EtAlCl 2 >Et 2 AlCl) pour la cyclisation d'aldehydes olefiniques par un mecanisme Prins interne ont ete compares en utilisant des systemes qui conduisent a des cycles a 5 chainons selon des processus ene de types I et II