STUDY ON REPRODUCTIVE ENDOCRINOLOGY OF HUMAN PLACENTA (Ⅱ)——HORMONE SECRETING ACTIVITY OF CYTO-TROPHOBLAST CELLS

The capability of cytotrophoblast cells to produce hCG, progesterone, estrogen, cGnRH and β-endorphin in vitro has been demonstrated in serum-free culture medium. Before experiment, a 24-h preculture was carried out in order to remove the endogenous hormones of the tissue. During a period of 8 days' culture, the cytotrophoblast cells could constantly produce a small amount of hCG. The production of progesterone rose rapidly and became doubled within six days. The estrogen secretion showed a similar pattern in the presence of androstenedione, a precursor of estrogen, indicating the elevation of aromatase activity in the cells. The elevation of the enzyme activity has been further demonstrated not to be induced by androstenedione. In both cytotrophoblast and syncytiotrophoblast cell cultures, cGnRH was only detected in the culture of cytotrophoblast cells, with a value up to 4 pg/105 cells/24 h. However, β-endorphin was identified both in cytotrophoblast and syncytiotrophoblast cells. Its content increa     

Synthesis and Antitumor Activity of Sorafenib Analogs Containing a Tetrazole Moiety

A novel series of diaryl biuret derivatives containing a tetrazole moiety was designed and synthesized.All the target compounds were evaluated for their in vitro antitumor activity against HT-29,HepG2,MCF-7 and A549 cells by MTT assay.Most of them exhibited obvious antitumor activity,and four of them(4a,4c,4h and 7a)were superior to sorafenib in general.Among them,Compound 4h displayed more potent activity than sorafenib in all tested cancer cells.Compound 4c exhibited the most outstanding activity in inhibition of growth of HepG2 cells(IC50=0.55 μmol/L).Further,they both revealed favorable metabolic stability in in vitro assay.Compounds 4c and 4h are promising candidates for further development.     

Synthesis,Characterization and in vitro Antitumour Activity of the Di—n—butyltin（IV） Complexes of Some Arylhydroxamates

Fourteen new di-n-butyltin(IV)complexes of hydroxamic acids of the formula Bu2SnL2(HL-hydroxamic acids)were synthesized by the reaction of Bu2SnO and hydroxamic acids in dry toluene and ethanol media.The compounds were characterized by elemental analyses,molecular weight,IR and 1H NMR spectoscopy.The results indicate that n-Bu2SnL2 have distorted trans-octahedral structure.The antitumor activity in vitro against human A-549 tumor cells and P388 leukemia was presented,and their structure-activity relationship was discussed.     

NIR photosensitizers activated by γ-glutamyl transpeptidase for precise tumor fluorescence imaging and photodynamic therapy

Photodynamic therapy(PDT), a light triggered therapeutic mode, has been recognized as an attractive treatment for oncotherapy.The phototoxicity to normal tissues during treatment limited the development of PDT owing to the always "on" properties of photosensitizers. Activatable photosensitizers are of great importance for improving the selectivity of PDT. Herein, we regarded the overexpressed GGT(γ-Glutamyl transpeptidase) enzyme in tumor cells as a biomarker and developed an activatable photosensitizer Cy-GGT by decorating a specific recognition moiety of GGT, L-glutamic acid, to a hemicyanine dye based on photosensitizer Cy-NH_2. Cy-GGT was in the "off" state with negligible fluorescence and suppressed singlet oxygen generation,but it could be specifically hydrolyzed to Cy-NH_2 in the presence of GGT, accompanied with significant fluorescence recovery and singlet oxygen generation increase under light irradiation. The in vitro and in vivo studies indicated that Cy-GGT was suitable for precise tumor imaging and could work as an efficient photosensitizer for inhibiting tumor growth.     

Novel plant activators with thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate scaffold： Synthesis and bioactivity

The 1,2,3-thiadiazole-carboxylate moiety was reported to be an important pharmacophore of plant activators.In this study,a series of novel plant activators based on thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate were designed and synthesized and their biological activity as plant activators was studied.The structures of the novel compounds were identifed by1H NMR,19F NMR and HRMS.The in vivo bioassay showed that these novel compounds had good effcacy against seven plant diseases.Especially,compounds 1a and 1c were more potent than the commercialized plant activator BTH.Almost no fungicidal activity was observed for the active compounds in the in vitro assay,which matched the requirements as plant activators.     

若干简单Plakoric acid类似物的合成及体外抗疟活性

Several simple analogues of peroxyplakoric acid were synthesized by using Kobayashi＇s method to construct the key 1,2-dioxane core and tested in vitro for antimalarial activity. The scope and limitation of the method was also briefly examined.     

Recent Progress in Boosted PDT Induced Immunogenic Cell Death for Tumor Immunotherapy

With the rapid development of materials science,photosensitive materials have been widely used in the field of immunogenic cell death(ICD),which was on account of the reactive oxygen species(ROS)generation by photosensitizer under light irradiation inducing cellular oxidative stress during the dying of cells.Considerable researches related to photodynamic therapy(PDT)induced ICD were conducted and exhibited brilliant performance in cancer immunotherapy.Herein,a variety of different strategies for PDT induced ICD have been summarized and discussed to provide researchers more inspiration for cancer immunotherapy.     

A smart DNA nanodevice for ATP-activatable bioimaging and photodynamic therapy

Rational design of activatable photosensitizers for controlled generation of singlet oxygen remains a challenge for precise photodynamic therapy(PDT). Herein, we present an aptamer-based nanodevice for adenosine 5′-triphosphate(ATP)-activatable bioimaging and PDT. The nanodevice is constructed by modifying ATP-responsive duplex DNA units and polyethylene glycol on the surface of a gold nanoparticle(AuNP) through the thiolate-Au chemistry. The DNA units were designed by the hybridization of the ATP aptamer strand with a methylene blue(MB)-modified complementary DNA(cDNA). The close proximity of MB to the surface of AuNP results in the low photodynamic activity of MB(OFF state). Once internalized into cancer cells, the ATP-binding induced conformation switch of aptamer strand leads to the release of the MB-bearing DNA strand from AuNPs, resulting in the activatable generation of singlet oxygen under light irradiation(ON state). We demonstrate that the DNA nanodevice represents a promising platform for ATP-responsive bioimaging and specific PDT in vitro and in vivo. This work highlights a potential way for specific tumor diagnosis and therapy.     

Synthesis and Insulin—sensitizing Activity of a Series of 2—Benzyl—1,3—dicarbonyl Derivatives

A series of 2-benzyl-1,3-dicabonyl derivatives was synthesized.Their insulin-sensitizing activity was evaluated in 3T3-L1 preadipocyte cells.Compounds3,26 and 27 were found to possess strong insulin-sensitizing activity in vitro and were selected for further hypoglycemic evaluation in vivo.     

Synthesis of a Nine-atom Germanium Cluster K_(0.5)[K(18-crown-6)]_(1.5)Ge_9·1.5en with Unprecedented “up” and “down” Chain Arrangement of Unit [-(Ge_9-K-Ge_9)~(3-)-]

A new complex K0.5[K(18-crown-6)]1.5Ge9·1.5en(1) which contains unprecedented "up" and "down" chain arrangement of unit [-(Ge-9-K-Ge9)3-] has been prepared by the reaction of K4Ge9 with HgS in ethylenediamine(en) in the presence of 18-crown-6(1,4,7,10,13,16-hexaoxacyclooctadecane), and characterized by X-ray structure analysis. The color of the title crystals(black), which is darker than that of the reported three compounds with chains of germanium clusters, may result from the naked K+ and their interactions with the chain. And the structure differences between 1 and the reported three compounds with chains of germanium have also been discussed.     

New calcium germanium nitrides: Ca2GeN2, Ca4GeN4, and Ca5Ge2N6

We report three new calcium germanium nitrides synthesized as crystals from the elements in sealed niobium tubes at 760 degrees C using liquid sodium as a growth medium. Black Ca2GeN2 is isostructural with the previously reported strontium analogue. It is tetragonal P4(2)/mbc (no. 135) with a = 11.2004(8) A, c = 5.0482(6) A, and Z = 8. It contains GeN2(4-) units which have 18 valence electrons, and consequently are bent, like the isoelectronic molecule SO2. In contrast, clear, orange Ca4GeN4 with fully oxidized germanium contains isolated GeN4(8-) tetrahedra and is monoclinic P2(1)/c (no. 14) with a = 9.2823(8) A, b = 6.0429(5) A, c = 11.1612(9) A, beta = 116.498(6) degrees, and Z = 4. Clear, colorless Ca5Ge2N6, also with fully oxidized germanium, contains infinite chains, 1 infinity[GeN2N2/2(5-)], of corner-sharing tetrahedra similar to those found in pyroxenes. However, the precise structure of this latter phase has not yet been determined because of twinning problems.     

EVIDENCE AGAINST THE PRODUCTION OF SUPEROXIDE BY PHOTOIRRADIATION OF HEMATOPORPHYRIN DERIVATIVE

Abstract Experiments were performed to ascertain whether superoxide anion (O₂⁻) was produced by the photodynamic activation of hematoporphyrin derivative (HPD). Three different systems were utilized to detect formation of O₂⁻, oxidation of epinephrine to adrenochrome, reduction of cytochrome c and reduction of nitro blue tetrazolium (NBT). The effects on these detectors under identical conditions for HPD + h ν were compared to those obtained with two O₂⁻ generating systems, riboflavin + by and xanthine-xanthine oxidase, and to a singlet oxygen generating system, photoradiation of methylene blue. The results indicated that HPD + hv differed from the two O₂⁻ generating systems in failing to reduce cytochrome c or NET, and that HPD + h ν was similar to the behavior of methylene blue + h ν . In addition, HPD + h ν but not the O₂⁻ generating systems could inhibit mitochondrial cytochrome c oxidase activity. We conclude that the photodynamic activation of HPD does not produce O₂⁻ as a major oxygen radical and that the effects of HPD + h ν on mitochondrial cytochrome c oxidase are not caused by O₂⁻.     

石墨炉原子化器中原子化过程的研究(Ⅲ)——石墨炉中锗的原子化机理

有关锗的石墨炉原子吸收光谱分析,文献报道较少,对锗的原子化机理,亦有不同的看法^[1~3].本文基于右墨炉中锗原孚化行为的观察,对锗原子形成的过程进行了讨论,认为原子化过程中,并存着二种还原反应:GeO₂(s)+C→GeO(g)+CO(g),GeO₂(s)+CO→GeO(g)+CO₂,而锗原子的形成是GeO(g)热分解的结果。     

Synthesis of β-Cyclodextrin-[60]fullerene Conjugate and Its DNA Cleavage Performance

A water soluble β-cyclodextrin (β-CD) functionalized [60]fullerene (C60-CD) was synthesized.The C60-CD-induced generation of reactive oxygen species (ROS),and DNA-cleavage ability and cytotoxicity of C60-CD were studied upon visible light irradiation,demonstrating that the compound is very promising in the applications of photodynamic therapy.The histological analyses demonstrate that C60-CD has no acute or subacute toxicity to living body.     

Thionated organic compounds as emerging heavy-atom-free photodynamic therapy agents

This minireview focuses on recent progress in developing heavy-atom-free photosensitizers based on the thionation of nucleic acid derivatives and other biocompatible organic compounds for prospective applications in photodynamic therapy. Particular attention is given to the use of thionated nucleobase derivatives as “one-two punch” photodynamic agents. These versatile photosensitizers can act as “Trojan horses” upon metabolization into DNA and exposure to activating light. Their incorporation into cellular DNA increases their selectivity and photodynamic efficacy against highly proliferating skin cancer tumor cells, while simultaneously enabling the use of low irradiation doses both in the presence and in the absence of molecular oxygen. Also reviewed are their primary photochemical reactions, modes of action, and photosensitization mechanisms. New developments of emerging thionated organic photosensitizers absorbing visible and near-infrared radiation are highlighted. Future research directions, as well as, other prospective applications of heavy-atom-free, thionated photosensitizers are discussed.

This minireview focuses on recent progress in developing heavy-atom-free photosensitizers based on the thionation of nucleic acid derivatives and other biocompatible organic compounds for prospective applications in photodynamic therapy.     

Synthesis of Germanium Oligomer from Germanium Dioxide

Several crystalline germanium oligomers Ge_nO_2n+1· L₂·xH₂O (L = amino acid or amine) have been prepared and characterized by IR and NMR spectra, EA (elemental analysis), TGA (thermogravimetric analysis) and ICP-AES (inductively coupled plasma-atomic emission spectroscopy). Oligomers of this type are based on chains of germanium-oxygen single and double bonds and synthesized in aqueous solution from germanium dioxide and basic ligands having an amino group. Two basic amino acids and mono-, and bidentate amines chosen as ligands to react with germanium dioxide gave L-lysine germanate (1a, 1b, 1c), L-arginine germanate (2a, 2b, 2c), Cyclohexylammonium hexagermanate (3), N-methylcyclohexylammonium hexagermanate (4), N,N-dimethylcyclohexylammonium hexagermanate (5), 2-aminoethylammonium trigermanate (6), 2-N′-methylammo)-N-methylethylammonium pentagermanate (7), 2-(N′N′-dimethylamino)-N′N-dimethylethylammonium heptagermanate (8).     

Synthesis, characterization, and growth rates of aluminum- and Ge,Al-substituted silicalite-1 materials grown from clear solutions

The synthesis, characterization, and growth rates of aluminum- and germanium,aluminum-substituted silicalite-1 (Al-silicalite-1, Ge,Al-silicalite-1) materials grown from clear solutions are reported. In the case of aluminum substitution, the crystallinity of the materials as determined by powder X-ray diffraction (PXRD) decreases with increasing aluminum content, as does the micropore volume determined by nitrogen adsorption and the growth rate determined by in situ small-angle X-ray scattering (SAXS). The final materials possess slightly lower Si/Al ratios than the initial synthesis mixtures based on X-ray fluorescence analysis. In the case of simultaneous incorporation of germanium and aluminum, the final materials have a slightly lower Si/Al ratio than the synthesis mixture but a much higher Si/Ge ratio, indicating the aluminum is more readily incorporated in the zeolite as compared to germanium. This result is consistent with studies of individual heteroatom substitution behavior. Germanium incorporation in the final material increases at higher heteroatom contents (Si/(Ge+Al) = 50 and 25). The promoting effect of germanium on the growth rate of silicalite-1 dominates at low heteroatom content (Si/(Ge+Al) = 100), leading to enhanced zeolite growth rates as compared to pure silicalite-1. This promoting effect is insensitive to the Ge/Al ratio at a Si/(Ge+Al) = 100. The influence of aluminum on the growth rate, as well as the crystallinity of final materials, becomes observable when the heteroatom content is increased (Si/(Ge+Al) = 50 and 25). This is the first study we are aware of that reports the synthesis of Ge,Al-substituted silicalite-1 phases formed in hydroxide media or from clear solutions and has implications for the synthesis of nanoparticulate zeolitic materials for catalysis.     

Structure—gas chromatographic retention time models of tetra-n-alkylsilanes and tetra-n-alkylgermanes using topological indexes

Structure—gas chromatographic retention time models were developed for 26 tetra-n-alkylsilanes, 26 tetra-n-alkylgermanes, and the mixed set of silanes and germanes using topological indexes. The topological indexes used were molecular connectivity indexes, the new Kier—Hall total topological indexes, and the new Kier—Hall electrotopological state atom index, S, for the silicon and germanium atoms. For the mixed data set, a model based on ¹χ, ³χ_c, and S gave r = 0.999 and s = 0.033. In two cases the residual was more than twice the standard error. Replacement of ¹χ by TTV, the new Kier—Hall total topological index using δ^v values for the silicon and germanium atoms, also gave r = 0.999 and s = 0.033 but in no case was there a residual greater than twice the standard error. A two-variable model based on ⁰χ^r, which uses δ^r values for the metal atoms, and ⁴χ_pc^v, which uses δ^v values for the metal atoms gave r = 0.999 and s = 0.035. The results demonstrate the adequacy of the Kier—Hall electrotopological state atom index for encoding the atomic characteristics of silicon and germanium in a mixed data set. The results show that the Kier—Hall total topological indexes can be used in place of ¹χ to encode the size and skeletal branching of silanes and germanes.     

Synthesis, structural characterization, and thermal stability of a new layered germanate structure, Na4Ge16O28(OH)12

The new layered germanate structure Na4Ge16O28(OH)12 has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, FTIR, and SEM. The crystal lattice parameters are a = 7.3216(6) A, b = 14.3986(9) A, c = 7.7437(6) A, alpha = 90.0 degrees, beta = 100.179(7) degrees, gamma = 90.0 degrees, and V = 803.5(1) A3. The space group is C2/m with Z = 1. The germanium oxide sheets are connected non-covalently via electrostatic interactions with the sodium cations and H-bridging. At temperatures above 400 degrees C, the structure starts decomposing into sodium enneagermanate (Na4Ge9O20), germanium dioxide, and water as determined by powder X-ray diffraction, TGA, DTA, DSC, and GCMS.