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Palladium acetate was supported on amorphous silica with the aid of an ionic liquid, [bmim]PF6. The immobilized catalyst was highly efficient in promoting the Mizoroki−Heck reaction without a ligand in n-dodecane for at least six reuses, in 89~98% yields. The TON and TOF reached 68 400 and 8000, respectively.

In the presence of a catalytic amount of lithium amide, the reaction of oxophorone with electron-deficient olefins afforded bicyclo[2.2.2]octane-2,5-dione derivatives in high yields. The reaction proceeds autocatalytically by an enolate of bicyclo[2.2.2]octane-2,5-dione, generated by an initial domino Michael reaction.

A phytotoxin, solanapyrone E, has been synthesized from the decalone prepared by the domino Michael reaction of the kinetic enolate of optically pure acetylcyclohexene with methyl crotonate. After several transformations on the decalone ring, condensation of a methyl acetoacetate equivalent installed a pyrone moiety and introduction of a hydroxymethyl unit into the pyrone ring furnished solanapyrone E.

The syntheses of 7-sila-7H-dibenzo[c,g]fluorenes 1 were effected via dilithiation of 2,2‘-dibromo-1,1‘-binaphthyl (2) followed by cyclization of the resulting dianion with dihalosilanes:  Me2SiCl2, Ph2SiCl2, and Ph2SiF2. The X-ray structural analysis of 7-sila-7,7-diphenyl-7H-dibenzo[c,g]fluorene (1b) provided the first geometrical parameters of the 7-sila-7H-dibenzo[c,g]fluorene derivative in which the silole skeleton was found to be twisted in the C2 symmetrical conformation due to the significant steric repulsion of the binaphthyl group fixed within the van der Waals radii. The photophysical study and semiempirical PM3 calculation suggested the presence of significant σ*−π* conjugation in the LUMO of the 7-sila-7H-dibenzo[c,g]fluorene 1 like a silole.

Brominative Si−Si cleavage of 3,4-disila-3,3,4,4-tetramethyl-3,4-dihydrodibenzo[c,g]phenanthrene (3a), LiAlH4 reduction of the resulting dibromide, and fluorination of the dihydride 14a thus gave 2,2‘-bis(fluorodimethylsilyl)-1,1‘-binaphthyl (7a) in high yield as the first isolated and fully characterized 2,2‘-bis(halosilyl)-1,1‘-binaphthyl. Similar conversion of the more sterically hindered 3,4-disila-3,3-dimethyl-4,4-diphenyl-3,4-dihydrodibenzo[c,g]phenanthrene (3b) also gave the corresponding bishydrosilane 14b. However, subsequent fluorination did not give the desired bisfluorosilane 7b but rather the hydrolyzed siloxane 6b. The syntheses of the disilanylene-bridged precursors 3 were effected via bis-silylation reactions of 2,2‘-dibromo-1,1‘-binaphthyl (DBBN, 2) with dihalodisilanes ClMe2SiSiMe2Cl, ClMe2SiSiPh2Cl, FMe2SiSiPh2F, and FPh2SiSiPh2F. Although ClMe2SiSiMe2Cl predominately gave the disilanylene-bridged product 3a, XMe2SiSiPh2X (X = F, Cl) produced not only the disilanylene-bridged product 3b but also the dimethylsilylene-bridged product 8a. FMe2SiSiPh2F served better in preparation of the desired 3b than ClMe2SiSiPh2Cl. The sterically hindered FPh2SiSiPh2F did not give silylation products. The X-ray structural analyses of 3a and 3b provided the first geometrical parameters of the 2,2‘-disilanylene-bridged 1,1‘-binaphthyl derivatives. In comparison with the acyclic analogues and less sterically hindered disilanylene-bridged biaryls such as 2,2‘-bis(trimethylsilyl)-1,1‘-binaphthyl ((±)-1a), (R)-(−)-2,2‘-bis(dimethylphenylsilyl)-1,1‘-binaphthyl ((R)-(−)-1b), dibenzo-1,1,2,2-tetramethyl-1,2-disilacyclohexa-3,5-diene (12), and dithienodisilacyclohexadiene 13 the disilanylene-bridged binaphthyls 3 were found to be highly strained due to the steric repulsion of the binaphthyl groups fixed in a narrow angle.

The naturally occurring guaianolides, namely mokko lactone (1), dehydrocostus lactone (2), eremanthin (3), and related guaianolides, 16, 17, 21, 22, 28−31, 33, 36, 37, and 39, have been synthesized starting from l-α-santonin in an effort to examine their structure−activity relationship as inhibitors of the killing function of cytotoxic T lymphocytes (CTL) and the induction of intercellular adhesion molecule-1 (ICAM-1). It was observed during the present study that the guaianolides possessing an α-methylene γ-lactone moiety, i.e., 2, 3, 30, 33, 37, and 39, exhibited significant inhibitory activity toward the killing function of CTL and the induction of ICAM-1.

A new synthesis of 3(2H)-furanones from 4-hydroxy-2-alkyn-1-one derivatives via CO2 mediated bond reorganization has been developed to the preparation of an antitumor agent, geiparvarin and a constituent of flavors, 2,5-dimethyl-3(2H)-furanone.

The syntheses of (−)-7βH-eudesmane-4α,11-diol (2) and (+)-ent-7βH-eudesmane-4α,11-diol (ent-2) were carried out starting from (−)- and (+)-dihydrocarvones. As a result, the structure, including absolute configuration, of the naturally occurring eudesmane-4,11-diol isolated from Pluchea arguta was determined to be (+)-ent-7βH-eudesmane-4α,11-diol (ent-2).

UC 729-6, a 6-thioguanine-resistant human lymphoblastoid B-cell line, was fused with normal and malignant human lymphocytes. Parent UC 729-6 cells were diploid with a 21p+ marker chromosome, expressed surface and cytoplasmic IgM kappa, and doubled every 17 hr. The resulting human-human hybridomas were pseudotetraploid containing the 21p+ marker, doubled every 20-30 hr, and secreted 3-9 micrograms of human Ig per ml per 10(6) hybrid cells for greater than 9 months in continuous culture. Human Ig-secreting hybridomas were generated in 88% (14/16) of the fusions carried out and were cloned by limiting dilution (one cell per three wells) without the use of feeder layers. The mean fusion frequencies (number of wells, plated at 10(5) cells per well, showing hybrid growth per 10(6) lymphocytes fused) of UC 729-6 with normal lymphocytes ranged from 0.45 to 2.9 and with malignant B lymphocytes, from 3 to 10. Analysis of the human-human hybridomas derived from lymphocytes isolated from regional draining lymph nodes of cancer patients revealed several that secreted human monoclonal antibody that reacted by an enzyme immunoassay with some carcinoma cell lines but not with normal fibroblast cell lines. These data suggest that (i) UC 729-6 can be fused with human lymphocytes to generate stable human-human hybridomas, some of which secrete antibody reactive to human cell surface antigens, and (ii) UC 729-6 can be used to rescue Ig from nonsecretory malignant B cells and thereby allow for the production of anti-idiotype antibodies.

Retinol, a morphogen, has been shown to induce morphological changes in vascular endothelial cells, accompanied by an acute and specific accumulation of an 80-kDa protein; purification and characterization of this retinol-induced protein (RIP) have revealed that it is a transglutaminase. Endothelial cells from bovine carotid artery were cultured, treated with retinol, and examined for changes in morphology and protein profiles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of extracts prepared from retinol-treated cells which had undergone a remarkable change in shape (from a cobblestone-like to a spindle-like shape) indicated that the retinol-induced morphological change is accompanied by a marked increase of an 80-kDa protein. Similar changes were also induced by retinoic acid. The 80-kDa RIP was purified by anion exchange and hydroxyapatite column chromatography. Amino acid sequencing of tryptic fragments of the purified RIP revealed a high degree of homology between the sequence of bovine RIP and that of guinea pig liver transglutaminase, suggesting that RIP is a transglutaminase. This was confirmed by activity measurements; RIP exhibited transglutaminase activity, and an antiserum against RIP immunoprecipitated the activity. These results suggest that transglutaminase plays important roles in the maintenance of morphology and the control of endothelial cell functions.

The inhibitory effect of a-tocopherol, ß-carotene, 2?-O-glycosyl isovitexin (2?-O-GIV), and butylated hydroxytoluene (BHT) on malonaldehyde (MA) formation from ?3 polyunsaturated fatty acids (PUFA) was determined by gas chromatography. The levels of MA formed from 1 mg each of octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) upon oxidation with Fenton's reagent were 29.8±1.5, 17.2±1.5, and 22.0±0.7 nmol, respectively. BHT was most effective toward protecting all three ?3 PUFA, whereas ß-carotene did not exhibit any inhibitory effect. 2?-O-GIV inhibited MA formation from EPA and DHA by 56 and 43%, respectively, showing the second greatest inhibitory activity after BHT. a-Tocopherol inhibited MA formation from ODTA and DHA by 67 and 28%, respectively, but it did not show any activity toward EPA oxidation. The naturally occurring antioxidant, 2?-O-GIV, may be useful to prevent oxidation of ?3 PUFA.

A novel electrochemically induced cis-to-trans isomerization process involving amphiphilic azobenzene derivatives in Langmuir−Blodgett monolayer films at electrode/electrolyte interfaces was examined using electrochemical and UV−visible absorption measurements. This isomerization proceeds electrostatically, i.e., with no Faradaic current and no discernible features in the double-layer capacitive charging current, when relatively positive electrode potentials are applied to the monolayer film. This electrostatically induced process is rather slow (first-order rate constants in the 10^-2−10^-1 s^-1 range over the potential range of +0.65 to +0.85 V vs Ag/AgCl, respectively), but the highest rate constant measured (at +0.85 V vs Ag/AgCl) represents an increase of approximately 3 orders of magnitude compared to that of the thermal isomerization process. Surprisingly, the activation energy for the electrostatic process was found to be essentially potential independent and nearly the same as that for thermal isomerization. The rate constants for the cis-to-trans isomerization obtained at given potentials were also found to depend sensitively on details of the molecular structure, such as the length of the alkyl chain connecting the carboxyl group to the azo group (spacer) and the length of the alkyl tail, which implies that the isomerization reaction involves an interaction between the intrinsic electric field of the molecules in the highly ordered film and the relatively strong electric field associated with the electrical double layer at the electrode surface.

Abstract: Antibodies in both their free and immobilized state have been the object of considerable industrial and academic interest. A variety of methods are used for preparing and immobilizing antibodies. Applications for monoclonal antibodies include the preparation of therapeutics, diagnostics, and in affinity fractionation. Recent US patents on monoclonal and immobilized antibodies and scientific literature on monoclonal antibodies are surveyed. A description of these patents and a list of references are given.

Conditioned medium from the Con A-treated mouse helper T-cell clone Ly1+2-/9 contains activities that enhance the production of IgA by mouse B cells and induce human cord blood cells to form eosinophil colonies. We have isolated a cDNA sequence that expresses IgA-enhancing factor and eosinophil colony-stimulating factor activities from a cDNA library prepared from activated Ly1+2-/9 cells. Based on homology with the mouse cDNA sequence, a human cDNA sequence coding for an interleukin with IgA-enhancing factor and eosinophil colony-stimulating factor activities was isolated from a cDNA library prepared from a human T-cell clone stimulated with anti-T3 antibody and phorbol 12-myristate 13-acetate. DNA sequence analyses revealed that mouse and human cDNA clones encode proteins of 133 and 134 amino acids, respectively, that are identical to cDNA clones encoding the T-cell replacing factor I and B-cell growth factor II activities. These results establish that a single cDNA clone encodes a protein that acts as a growth and differentiation factor for both B cells and eosinophils.