THE SPECIFIC PHOTODYNAMIC EFFECTS OF MONOCLONAL ANTIBODIES CONJUGATED WITH HEMATOPORPHYRIN DERIVATIVE ON GASTRIC CANCER IN VITRO AND IN VIVO

Murine monoclonal antibody (MoAb) BB4.3, raised against the human gastric cancer cell line BGC823, was puriffied with Protein A-Sepharose CL-4B affinity chromatography and identified as IgG2a. It was then conjugated with a hematoporphyrin derivative (HPD) by using carbodiimide. The qualitative analysis of this conjugate showed that the amount of free HPD was negligible and there were no IgG aggregates among the conjugates. The conjugate retained both the antibody and photochemical activity of HPD.In vitro, the phototoxic effect of this HPD-BB4.3 conjugate on target cells was about 15 times higher than that of free HPD. The quality of selective photocytotoxicity was proven by the greater cytotoxi-city this conjugate showed than that of corresponding normal mouse IgG (NIgG) conjugated with HPD. It showed less cytotoxicity to colon cancer cell line B-80 (negative reaction to MoAb BB4.3) than to BGC825. Moreover, its cytotoxicity to BGC823 cells could be blocked specifically by excess BB4.3 antibody, but not by another MoAb 3G9, which combines with BGC823 at different binding sites from MoAb BB4.3.Nude mice inoculated with 2 × 10- BGC823 cells were given HPD-BB4.3, HPD, HPD-NIgG, HPD plus BB4.3 and PBS, respectively then exposed to light. Four out of six animals treated with the HPD-BB4.3 conjugate remained tumor-free for a long period. Although two developed tumors, there was a significant difference between the HPD-BB4.3-treated group and all the control groups in tumor induction time, tumor growth rate, and survival time (p<0.001). The HPD-BB4.3 conjugate inhibited the growth of established tumors by more than 40% in comparison with control groups (p<0.05).

A STUDY ON THE STRUCTURAL EFFECT OF DOUBLE BRIDGES CONJUGATED SYSTEMS I.CARBONYL-IMINO SYSTEM

The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation.

Electron Correlation Effects in Polaron-Pair Recombination in Conjugated Polymers

Within a Su-Schriffer-Heeger model modified to include electron-electron interaction and an external electric field, we investigate the dynamics of oppositely charged polarons in a polymer chain in the presence of both electron-phonon and electron-electron interactions under the influence of an external electric field. We adopt a multi-configurational time-dependent Hartree-Fock method for the time-dependent Schrodinger equation and the Newtonian equation of motion for a lattice. Our results show that the on-site Coulomb interaction is of fundamental importance and favors the recombination between the pairs of polarons, and the yield of excitons depends crucially on the strength of the on-site Coulomb interaction U. Furthermore, the influence of the nearest neighbor interaction V is also discussed.

Quadruple[6]Helicene Featuring Pyrene Core:Unraveling Contorted Aromatic Core with Larger Effective Conjugation

Multiple helicenes display distinct aromatic cores characterized by highly twisted rings that are shared or fused with constituent helicene moieties.Diversifying these aromatic cores unlocks avenues for creating multiple helicenes with distinct properties and topologies.Herein we report the synthesis of a quadruple[6]helicene featuring pyrene as the aromatic core.The synthesis involved key steps of the annulativeπ-extension reaction and Scholl reaction.By extending multiple helicenes along the axial direction,the degree of contortion of the aromatic core can be controlled from nearly flat to highly twisted.Notably,quadruple[6]-helicene exhibits a significant red-shift of 0.49 eV compared to quadruple[4]-helicenes,of which the red-shift arises from bothπ-extension and augmented effective conjugation due to enhanced twisting.Quantum chemical calculations demonstrate that the degree of contortion in the pyrene core adeptly governs the energy levels of the HOMO and LUMO,which offers an alternative strategy beyond mere enlargement of theπbackbone.An intriguing serendipitous finding reveals the formation of one-molecule-thick supramolecular homochiral nanosheets through selfinterlocking interactions of enantiomers in single crystals,a rare packing motif for multiple helicenes.

DFT Study on the Antioxidant Activity of a Modeled p-Terphenyl Derivative

Relationships between the structure characteristics of natural p-terphenyl com- pounds isolated from three edible mushrooms （Thelephora ganbajun, Thelephora aeronautical, and Boletopsis grisea） indigenous to China and their mechanism of antioxidant activity were studied. Geometry structures of terphenyl molecule and four corresponding radicals, bond dissociation energy （BDE）, frontier orbitals （HOMO and LUMO） and single electron density were calculated using DFT methods （B3LYP/6-311G＊＊）. The computational results which are consistent with the experimental data well show that terphenyl molecule scavenges DPPH radical by hydrogen abstract mechanism and the high antioxidant activity depends on the substitution position of hydroxyls. Two active 7-, 8-hydroxyls facilitate the hydrogen abstraction due to the intramolecular hydrogen bond and the resonance effect makes 4-hydroxyl radical more stable.

Theoretical Study of the Isomerization Reaction of 1-3 H Transfer on Formamidine Substituted by Halogen

The ab initio method has been used to study the 1-3 H transfer reaction on formamidine substituted by halogen. The calculation results show that the substituted halogen has two effects on the 1-3 H transfer reaction: decreasing the activation energy and stabilizing the C=N double bond owing to the conjugative effect of p-π-p of products and transition states.

Influence of Mg/Al Molar Ratio on the Structures and Properties of Ru-Mg Alx Catalysts for Isomerization Linoleic Acid

With the knowledge on the significant effect of basic site and Ru on the catalytic performance of heterogeneous catalysts in the isomerization of linoleic acid to conjugated linoleic acid,a series of Ru-Mg Alx compounds with different basicity have been prepared by controlling the Mg/Al molar ratio. The results showed the catalysts with different basicity markedly influence the structure,the Ru dispersion,properties and catalytic performances for the isomerization reaction. The strong basic site is conductive to the high yield of CLA products. The strong basic site and the well-dispersion RuO2synergetic catalysis for the isomerization reaction,basic site and the well-dispersion RuO2synergetic effect are possibly via a Mg-O-Ru linkage.

STRUCTURAL EFFECT IN FORKED CONJUGATIVE SYSTEMS——BIFURCATION-TYPE OF FORKED POLYENIC NITRILES,CARBOXYLIC ACIDS AND ESTERS

Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano and carboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon the introduction of an electron-attractive branching group, just like the case of introducing an electron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the corresponding forked compounds, the equivalent △Ns for a branching group may be calculated with accuracy. Based on the value of this equivalent, the substituentnature of the structural effect of the branching group has been inferred. The electronic absorption maxima for four series of the forked compounds have been cal-culated by means of the extended homologous equation for the corresponding linear compounds.With an appropriate correction for the positional effect of the substituent equivalent, the cal-culated wavelengths agree generally with experimental data within ± 7nm.

Studies on the effect of opposite terminal groups in phenylpolyenic conjugative systems

Seven homologous series p-A=B-C_6H_4(CH=CH)_nX=Y (A=B: NO_2, X=Y: CHO, COMe, CN, NO_2; A=B: CN, X=Y: CHO, CN; A=B: H, X=Y: NO_2) were synthesized, the effect of opposite terminal groups in phenylpolyenic conjugative systems has been studied by means of UV, XPS, ^(13) C NMR and quantum chemical calculation. The results show that: 1. There exists the effect of opposite terminal groups exists in phenylpolyenic and other aromatic conjugative systems. 2. When A=B and X=Y are the same, the group (-X=Y) connected at polyenic chain is a terminal group, while the other is an opposite terminal group. When the two groups are different, the one with weaker conjugative power plays the role of the opposite terminal group. 3. The effect of opposite terminal groups increases successively in the order of CN, COMe, CHO, NO_2 and can be quantita- tively described with substitute equivalent △N_s. Theλ_(max) of compound containing an opposite terminal group can be calculated by the homologous equation 10^(-4) =a+b/(1/2)^(2/N＇^(-S)_a), most of the calculated values are in agreement with experiment results.

A Series of Soluble Planar Oligorylenes up to Hexarylene

Preparation of large rylenes often needs the use of solubilizing groups along the rylene backbone,which results in the distortion of the skeleton and thus broadening of the absorption spectrum.In this work,we successfully synthesized 2,5,8,16,19,22-hexakis[2,6-bis(tri-fluoromethyl)phenyl]hexarylene(H)by using an oxidative fusion reaction of perylene trimer in 5%yield.The product is soluble in common organic solvents and could be purified with column chromatography.Single-crystal X-ray diffraction analysis revealed that the hexarylene core is not disturbed by the substituents very much and is almost planar.The longest absorption of H exhibits a sharp peak at 831 nm and an on-set at 875 nm in toluene with a small full-width-at-half-maximum(FWHM)of 660 cm^(-1).The molar extinction coefficient is as large as 131,000 M^(-1)cm^(-1).The substituents could not perturb the electronic properties of the hexarylene because aryl groups are perpendicular to the hexarylene core and the carbon atoms at 2,5,16,19-positions have negligible coeffi-cients on its HOMO and LUMO,estimated by theoretical calculations.As a result,the hexarylene having less absorption at the visible light region was stable enough in solution under the LED room light for more than 1 week.This strategy gives a useful guideline to establish the near-infrared materials that exhibit stability under ambient conditions.

Synthesis, electrostructure and spectral property of oligo-(phenylene vinylenes) with different chain lengths

The syntheses of a series of oligo (phenylene vinylenes) (OPVs) were described. The extended π-chains were built up by sequences of Wittig reactions. Their electronic structures were systematically studied with absorption spectra, photo-luminescent spectra. The influences of the effective conjugation length on the performance of the light emitting devices were investigated.