Synthesis and Photodynamic Activity of Peri-xanthenoxanthene Derivatives.

Photodynamic therapy (PDT) is a modern cancer therapy. But it is still difficult to obtain ideal photosensitizers. We synthesized six new peri-xanthenoxanthene derivatives rapidly and efficiently using solid-phase carbon-bath microwave irradiation technology, and investigated their in vitro photodynamic antitumor activity with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our results showed that all compounds exhibited extremely low dark cytotoxicity and good phototoxicity against four human cancer cell lines. In particular, compound 3c showed the best in vitro PDT activity against Hela cells and Bel-7402 cells with IC50 values of 91 and 74 nmol/L, respectively. Its value of 1-octanol/water partition coefficient (log Kow) was 0.5309, suggesting that it is a promising photosensitizer for PDT due to its low dark cytotoxicity, high phototoxicity, and potential water solubility.

[Study on Glycosides Constituents from Guangdong Liangcha Granules(II)].

OBJECTIVE: To study the glycosides from Guangdong Liangcha Granules. METHODS: The chemical constituents were isolated by various chromatographic techniques and the structures of chemical constituents were identified by spectroscopic analysis and literature. RESULTS: Six compounds were isolated and identified as ilexoside B (1), asprellanosides B (2), asprellanoside A (3), 4', 5 ,7 -tri- hydroxyflavone-6-O-ß3-D-glucopyranosyl ester(4), isoviolanthin (5),3-O-methy-lellagic acid 4'-O-rhamnopyranoside (6). CONCLUSION: Compounds 1 - 5 are firstly obtained from Guangdong Liangcha Granules.

3-[(E)-1-(Benzyl-oxyimino)-eth-yl]-7-(3-methyl-but-2-en-yloxy)-2H-chromen-2-one.

In the title compound, C(23)H(23)NO(4), the dihedral angle beween the chromen-2-one ring system and the benzene ring is 69.73 (10)° and the mol-ecule adopts an E conformation with respect to the C=N double bond. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds occur, generating R(2) (2)(12) loops.

Design, synthesis and biological evaluation of hydroxy- or methoxy-substituted phenylmethylenethiosemicarbazones as tyrosinase inhibitors.

A series of hydroxy- or methoxy-substituted phenylmethylenethiosemicarbazones were designed, synthesized and evaluated as mushroom tyrosinase inhibitors. The results demonstrated that most of target compounds had remarkable inhibitory activities on mushroom tyrosinase. Interestingly, compound 2h was found to be the most potent tyrosinase inhibitor with IC50 value of 0.18 microM. The possible interaction mode between compound 2h and tyrosinase was proposed. In addition, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of select compounds (IC50<10.0 microM) were also investigated. Compounds 2d, 2e, 2h, 2i and 2l exhibited more potent DPPH radical scavenging activity than well-known antioxidants ascorbic acid (Vc) and tertiary butyl hydroquinone (TBHQ). These results suggested that such compounds might be utilized for the development of new candidate for treatment of dermatological disorders.

Optical behaviors of conjugated-chain compounds containing benzene and furan units.

Thirteen conjugated-chain compounds which contain benzene and furan units were prepared, their optical behaviors, including UV-vis absorption coefficient (epsilon), absorption wavelengths (lambdaa), fluorescence emission wavelengths (lambdae), and quantum yields (Phi) were measured. Meanwhile, their LUMO and HOMO energy were determined by cyclic voltammetry and their second-order polarizations (betaxxx) values were determined by solvatochromic method, respectively. The results showed that this kind of compounds possess a shorter lambdaa (320-365 nm) and performance a higher Phi values, especially for 2aa, 2ab, 2ac and 2bb, their Phi values are all more than 90%. These compounds, except 2db, showed a higher betaxxx values in DMSO, especially for 2dc (75.77x10(-30) m5 C-1) and 2dd (83.32x10(-30) m5 C-1), than that 10-methyl-acridone (6.578x10(-30) m5 C-1) or 10-benzylacridone (6.845x10(-30) m5 C-1) in DMSO did, and second harmonic generation value of 10-methylacridone and 10-benzylacridone in powder are, respectively, 1.381 and 1.861 times of that value of urea. The betaxxx values and Phi values determined for these compounds in this work were lower than these values which were desired in the original work, this phenomena was explained from their molecular structures. This work confirmed that as these compounds performance shorter lambdaa and higher Phi values, they could be good blue-color optical materials for some fields, such as OLED materials, two-photo absorption materials, fluorescent dyes.

Bidirectional iterative synthesis of alternating benzene-furan oligomers towards molecular wires.

Reaction of propargylic dithioacetal 2a with BuLi gives the sulfur-substituted allenyllithium 3a which is allowed to react with a dialdehyde to yield the corresponding alternating benzene-furan oligoaryls 6. Functional group transformation converts the ester groups in 6 to dialdehyde 8 which can be used for the synthesis of higher homologues towards molecular wires. A combination of this furan annulation, Heck reaction and Sonogashira coupling leads to a variety of benzene-furan-alkene/alkyne conjugated oligomers of precise length.

Study on the second-order optical behavior of 4-(substituted-benzylidene)-2-phenyl-4H-oxazol-5-one.

The maximum absorption wavelengths (lambda(a-max)), absorption coefficient (epsilon), maximum emission wavelengths (lambda(e-max)) of 4-benzo[1,3]dioxol-5-ylmethylene-2-phenyl-4H-oxazol-5-one (1), 4-(3,4-dimethoxybenzylidene)-2-phenyl-4H-oxazol-5-one (2) and 4-(3,4,5-trimethoxy-benzylidene)-2-phenyl-4H-oxazol-5-one (3) were measured, their second-order nonlinear polarization values (beta(xxx)) were determined by solvatochromic method. Although the spectral nature (lambda(a-max), epsilon, lambda(e-max)) and beta(xxx) values of 1, 2 and 3 were close to each other in the same solvent, the second-order harmonic generation (SHG) value of sample 1 is higher obviously than that of sample 2 or 3 in solid state. The crystal structures of 1 and 2 characterized by single crystal X-ray diffraction technique indicated the reason why the SHG value of 1 is higher.

Molecular complexes of antipsychotic pharmaceutical parent molecule phenothiazine and unsaturated acid anhydrides.

The charge-transfer complexes (CTC) between a parent molecule of antipsychotic pharmaceuticals, phenothiazine, and seven unsaturated acid anhydrides, 1,4,5,8-naphtalenetetracarboxylic dianhydride, diphenic anhydride, maleic anhydride (MA), 3,4,5,6-tetrahydrophthalic anhydride (THPA), 3-hydroxy-1,8-naphthalic anhydride (HONA), 4-chloro-1,8-naphthalic anhydride (ClNA), and 1,8-naphthalic anhydride (NA) were studied using IR and UV spectroscopy. Stability constants (K) at different temperatures were measured, and based on the K's DeltaH and DeltaS were calculated. The values of electron affinity (E(A)) of anhydrides were obtained according to Mulliken's theory. The results show that phenothiazine is an excellent donor and has strong ability to complex with the carbonyl group, and the E(A) values have good linear relationships with DeltaH and K, respectively. The solvent effect on CTCs was also determined and explained. The CTC of phenothiazine-succinic anhydride (SA) was studied under the same conditions. It was deduced from the results obtained that there were two charge-accepting centers in the unsaturated acid anhydrides when they formed CTCs with phenothiazine. The first one was carbon atom of the two carbonyl groups and the second one was their -C=C- in the molecules.

Study on the optical properties of 4,4'-bis-(2-(substituted-styryl))biphenyl and 1,4-bis-(2-(substituted-styryl))benzene.

The maximum absorption wavelengths (lambda(a-max)), absorption coefficient (epsilon), maximum emission wavelengths (lambda(e-max)), fluorescent quantum yields (phi(f)), and second-order nonlinear polarizations (beta(xxx)) of seventeen 4,4'-bis-(2-(substituted-styryl))biphenyl and three 1,4-bis-(2-(substituted-styryl))benzene were measured. The results showed that some of this series of compounds possess high fluorescent quantum yields in DMF, such as, 2 (0.801), 3 (0.680), 5 (0.565), 15 (0.538) 16 (0.848), 18 (2.175), 19 (1.314) and 20 (1.060), as compared with quinine-sulfuric acid. They could be used as fluorescent whiteners and fluorescent colorants. Some of these compounds were of a high beta(xxx) values, such as in DMSO, 2 (29.00/10(-30) m(5)c(-1)), 3 (25.29/10(-30) m(5)c(-1)), 8 (21.79/10(-30) m(5)c(-1)) and 9 (24.08/10(-30) m(5)c(-1)). Electron-withdrawing substituent NO(2), which is attached to the two terminal phenyl rings could cause lambda(a-max) obviously to be shorter, but it made lambda(e-max) change longer. Electron-donating substituent at two end benzene rings, such as OCH(3), N((CH(3))(2)), even Cl, could make lambda(a-max) and lambda(e-max) longer, and the larger the electron-donating ability of the substituent, the longer the lambda(a-max) and lambda(e-max). This influence of 4-position substituent on lambda(a-max) or lambda(e-max) is obviously larger than that of 2-position substituent, and the action of substituent on 2-position is larger than that of substituent on 3-position. The values of lambda(a-max) and lambda(e-max) of biphenyl compounds 2 or 3 were respectively close to these values of corresponding benzene compounds 18 or 19.

Synthesis and optical behaviors of 2-(9-phenanthrenyl)-, 2-(9-anthryl)-, and 2-(1-pyrenyl)-1-alkylimidazole homologues.

Eight 2-(9-phenanthrenyl)-, 2-(9-anthryl)- and 2-(1-pyrenyl)-1-alkyl-benzimidazole compounds, three 2-(9-anthryl)-1-alkylphenanthroimidazole compounds and five 4,5-diphenyl-1-alkyl-2-(9-anthryl)imidazole compounds were synthesized by alkylation reactions of the corresponding benzimidazole, phenanthroimidazole or imidazole compounds. 2-(10-Bromo-9-anthryl)-1-alkyl-benzimidazole compounds were prepared by bromination reaction of 2-(9-anthryl)-1-alkylbenzimidazole compounds. All the synthesized compounds were characterized by elemental analysis, (1)H NMR, (13)C NMR, MS or HRMS; their absorption coefficients (epsilon), maximum absorption lambda(amax), fluorescence emission maximum lambda(em), Stokes shifts and fluorescence quantum yields (Phi(F)) in ethyl acetate were determined; their fluorescent lifetimes (T(1) and T(2)) were measured in ethyl acetate and in solid state, respectively. The crystal structure of 2-(9-anthryl)-1-n-butyl-4,5-diphenylimidazole (12a) was determined to be triclinic, space group P-1 types, using single crystal X-ray crystallography technique. The results showed that these compounds exhibited moderate fluorescence-emission abilities and higher solubility in most organic solvents than their corresponding starting materials. The relationships between the optical behaviors and structures for these compounds were discussed.