Aqua-(μ-cone-26,28-dibut-oxy-25,27-bis-{N-[5-(dimethyl-amino)-naphthalene-1-sulfon-yl]carbamoylmeth-oxy}-5,11,17,23-tetra-kis-(1,1-dimethyl-eth-yl)calix[4]arene(2-))disodium acetonitrile tetra-solvate.

The structure of the title complex, [Na(2)(C(80)H(98)N(4)O(10)S(2))(H(2)O)]·4CH(3)CN, obtained after crystallization from aceto-nitrile, contains two formula units in the asymmetric unit (Z' = 2) and an estimated four mol-ecules of acetonitrile per calixarene moiety. It is unusual for two Na(+) ions to occupy the lower rims of the cone calix[4]arene, as in this case, with one Na(+) ion forming two O→ Na(+) coordinate bonds with the two but-oxy groups and four such bonds with the two N-dansyl carboxamide groups, forming six dative bonds between Na(+) and O. On the other hand, the other Na(+) ion forms only five O→Na(+) coordinate bonds on the far end of the calix[4]arene lower rim, bringing the two dansyl groups in close proximity with each other.

New fluorogenic dansyl-containing calix[4]arene in the partial cone conformation for highly sensitive and selective recognition of lead(II).

A new efficient and highly selective fluorescent chemosensor for determination of Pb (2+) has been obtained by covalent attachment of two pendent proton-ionizable dansylcarboxamide groups to the calix[4]arene preorganized in the partial cone conformation. This geometry of the calixarene moiety was chosen on the basis of the prior (1)H NMR study of conformations adopted by the flexible dansyl-containing prototype upon complexation with lead ion. In acidic MeCN-H2O (1:1 v/v) solutions, the partial cone fluoroionophore allowed for detection of Pb (2+) at the levels as low as 2.

Effective therapy of murine models of human leukemia and lymphoma with radiolabeled anti-CD30 antibody, HeFi-1.

CD30 is a member of the TNF receptor superfamily. Overexpression of CD30 on some neoplasms versus limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise.

A dendrimer-based nanosized contrast agent dual-labeled for magnetic resonance and optical fluorescence imaging to localize the sentinel lymph node in mice.

Purpose: To preoperatively and intraoperatively localize the sentinel lymph node (SLN), a single hybrid probe for MR and near infrared (NIR) optical imaging was synthesized and tested.

Materials And Methods: A macromolecular MR/NIR optical contrast agent was synthesized based on a approximately 191 gadolinium-labeled contrast agent using generation-6 polyamidoamine dendrimer (G6), which is also labeled with 2 Cy5.5, an NIR fluorophore.

Optical determination of thallium(I) and cesium(I) with a fluorogenic calix[4]arenebis(crown-6 ether) containing one pendent dansyl group.

A fluorogenic derivative of 1,3-alternate calix[4]arenebis(crown-6) (1) containing a dansyl group in the proton-ionizable side arm has been employed in selective sensing of Tl+ and Cs+ at low concentration levels in MeCN-H2O (1:1) mixed solvent. Optical recognition of these two metal cations by 1 occurs in contrasting modes. On the basis of the results of fluorescence, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 1H NMR studies, Tl+ and Cs+ react with 1 via formation of 1:1 complexes that differ in coordination arrangement around the metal ion.

The anti-CD25 monoclonal antibody 7G7/B6, armed with the alpha-emitter 211At, provides effective radioimmunotherapy for a murine model of leukemia.

Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise. alpha-Particles are very attractive for cancer therapy, especially for isolated malignant cells, as is observed in leukemia, because of their high linear energy transfer and short effective path length. We evaluated an anti-CD25 [interleukin-2 receptor alpha (IL-2R alpha)] monoclonal antibody, 7G7/B6, armed with (211)At as a potential radioimmunotherapeutic agent for CD25-expressing leukemias and lymphomas.

Dendrimer-based nanoprobe for dual modality magnetic resonance and fluorescence imaging.

A novel PAMAM dendrimer-based nanoprobe for dual magnetic resonance and fluorescence imaging modalities was synthesized. Fluorescence studies revealed that Gd(III) complexation to the probe has no effect on the quantum yield; however, increases in the dye content resulted in partial quenching. The potential of the new nanoprobe, G6-(Cy5.

Preparation and in vivo evaluation of a novel stabilized linker for 211At labeling of protein.

Significant improvement of in vivo stability of 211At-labeled radioimmunoconjugates achieved upon employment of a recently reported new linker, succinimidyl N-2-(4-[211At]astatophenethyl)succinamate (SAPS), prompted additional studies of its chemistry. The 211At radiolabeling of succinimidyl N-2-(4-tributylstannylphenethyl)succinamate (1) was noted to decline after storage at -15 degrees C for greater than 6 months. Compound 1 was found to degrade via a ring closure reaction with the formation of N-2-(4-tributylstannylphenethyl)succinimide (3), and a modified procedure for the preparation of 1 was developed.

Effective treatment of a murine model of adult T-cell leukemia using 211At-7G7/B6 and its combination with unmodified anti-Tac (daclizumab) directed toward CD25.

Adult T-cell leukemia (ATL) consists of an overabundance of T cells, which express CD25. Therapeutic efficacy of astatine-211 ((211)At)-labeled murine monoclonal antibody 7G7/B6 alone and in combination with daclizumab was evaluated in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice given injections of MET-1 human T-cell leukemia cells. Daclizumab and 7G7/B6 are directed toward different epitopes of CD25.

Novel fluorogenic calix[4]arene-bis(crown-6-ether) for selective recognition of thallium(I).

A new fluorogenic, dansyl group-containing derivative of 1,3-alternate calix[4]arene-bis(crown-6-ether) provides optical recognition of Tl+ with selectivity over many other metal cations, including Na+, K+, Ca2+, Ag+, Hg2+ and Pb2+, and embodies the first example of a calixarene-based fluorescent Tl+-chemosensor.

Preparation and in vivo evaluation of novel linkers for 211At labeling of proteins.

The syntheses, radiolabeling, antibody conjugation and in vivo evaluation of new linkers for (211)At labeling of monoclonal antibodies are described. Syntheses of the N-succinimidyl esters and labeling with (211)At to form succinimidyl 4-methoxymethyl-3-[(211)At]astatobenzoate (9) and succinimidyl 4-methylthiomethyl-3-[(211)At]astatobenzoate (11) from the corresponding bromo-aryl esters is reported. Previously reported succinimidyl N-{4-[(211)At]astatophenethyl}succinamate (SAPS) is employed as a standard of in vivo stability.

Rigid versus flexible: how important is ligand "preorganization" for metal ion recognition by lower rim-functionalized calix[4]arenes?

For an assessment of the outcomes from use of an appropriately "preorganized" calixarene-based ionophore versus its conformationally mobile prototype, solvent extraction propensities of flexible calix[4]arene di-[N-(X-sulfonyl)carboxamides] for alkali, alkaline earth metal cations, Pb2+, Ag+ and Hg2+ are compared with those for seven new rigid analogs fixed in the cone, partial cone and 1,3-alternate conformations. For each of the metal ions, the preferred calix[4]arene conformation was determined from the NMR spectra for the metal salt of the flexible ligand. Except for Ag+, flexible calix[4]arene di-[N-(X-sulfonyl)carboxamides] were found to provide greater metal ion extraction efficiency and better selectivity than the corresponding "preorganized" ionophores.

New Proton-Ionizable Lariat Ethers with Picrylamino-Type Side Arms and Their Alkali Metal Salts. Synthesis and Structural Studies(1).

Twelve novel proton-ionizable dibenzo lariat ethers with picrylamino-type sidearms attached to the central carbon of a three-carbon bridge have been prepared in high yields by a three-step synthesis from the lariat ether alcohols via the corresponding lariat ether mesylates and amines. Structural studies conducted in solution by (1)H NMR spectroscopy and in the solid state by X-ray diffraction show that the picrylamino-type lariat ethers are preorganized for metal ion complexation with the sidearms oriented toward the macrocyclic polyether cavities due to intramolecular NH.O bonding.