Synthesis of Precocene-I Dimer. A Potential Antijuvenile Hormone

Precocene-I (1) (7-methoxy-2, 2-dimethylchromene) and precocene-II (6,7-dimethoxy-2, 2-dimethylchromene) isolated from Ageratum houstonianum plants have been shown to exhibit novel antijuvenile hormone activity¹. These compounds induce precocious metamorphosis in young nymphal stages of test insects resulting thereby into unviable miniature adults showing distinct cessation of juvenile hormone mediated functions. One of the views regarding the mode of action of these compounds suggests importance of the presence of unsubstituted 3,4 double bond in the molecule² and possible formation of 3,4-epoxide³ of precocenes via the diol^4,5 which might be the species responsible for the anti JH activity.     

二次导数线性变位示波极谱研究

利用二次导数线性变位示波极谱法测定可逆波、络合吸附波和催化波,均可以获得很高的灵敏度.文中还对可逆波、络合吸附波的性质从理论上进行探讨,并给出了这些波的理论公式.     

Spirodiclofen Derivatives as Highly Potential Acaricides:Synthesis,Structure and Bioactivity

A series of new compounds as highly potential acaricides was synthesized based on the structure of spirodiclofen. Their structures were identified by 1H NMR spectroscopy and element analysis. The bioassay indicated that most of the compounds exhibited excellent acaricidal activities, what's more, the bioactivities of some new compounds were better than that of the commercial spirodiclofen at a concentration of 20μg/mL. The relationship between structure and biological activity was also discussed.     

Tetraphenylantimony Carbonate. Synthesis and Structure

Pentaphenylantimony Ph₅Sb was reacted with triphenylantimony carbonate in toluene to obtain tetraphenylantimony carbonate. The structure of monoclinic crystals of tetraphenylantimony carbonate was studied.     

Potential cerebral perfusion agents. Synthesis and evaluation of a 1,4-disubstituted dihydropyridine analogue

The synthesis of a 1,4-disubstituted dihydropyridine, 1-(E-1[¹²⁵I]iodo-1-penten-5-yl)-4-(β-N-acetylaminoethyl)-1,4-dihydropyridine ([¹²⁵I] 10 ), is described. Acetylation of 4-(β-aminoethylpyridine) with acetic anhydride followed by condensation with E-1-borono-5-iodo-1-pentene ( 7 ) gave 1-(E-1-borono-1-penten-5-yl)-4-(β-N-acetylaminoethyl)pyridinium iodide ( 8 ). Chloramine-T and sodium iodide iodination of 8 gave the corresponding E-1-iodo compound 9 which was reduced with sodium borohydride to furnish 1-(E-1-iodo-1-penten-5-yl)-4-(β-N-acetylaminoethyl)-1,4-dihydropyridine ( 10 ). The corresponding radioiodinated compound was prepared similarly using Na[¹²⁵I]. The tissue distribution studies in rats indicate that [¹²⁵I] 10 crosses the blood brain barrier (0.49% dose/g in the brain) but gradually washes out from the brain.     

First Synthesis and Structure of a Tetraazasilafenestrane

A shift from the computational to the synthetic side has taken place in the quest for compounds containing planar‐tetracoordinate silicon: The first tetraazasilaspiro[4.4]nonane with two alkylene bridges has been prepared [Eq. (1)]. According to the X‐ray structure analysis, the angle between the two diazasilacyclopentene rings is 84.7°. AIBN=azobisisobutyronitrile, X=Br.     

Synthesis and Structure of a Titanocene-ferrocenyl Complex

A titanocene-ferrocenyl complex, （5-ferrocenyl-2-hydroxybenzenecarboxylato- O,O′）-bis（methylcyclopentadienyl）titanium（IV） 4, and an unexpected ionic complex, [C7H8NO3]- [（C5H5）Fe（C5H4）SO3]·H2O3 were synthesized and characterized by IR, ^1H NMR and elemental analysis. Compound 3 is of triclinic, space group P1 with a = 5.954（2）, b = 13.208（5）, c = 13.252（5） A, α = 60.993（7）,β = 84.342（8）,γ = 86.933（8）°, Z = 2, V = 906.8（6）A^3, Dc = 1.601 g/cm^3, μ（MoKα） = 0.987 mm^-1, F（000） = 452, the final R = 0.0647 and wR = 0.1333 for 2311 observed reflections （I 〉 2σ（I））. Compound 4 belongs to the monoclinic system, space group P2 1/c with α = 14.3310（9）, b = 12.5065（8）, c = 12.9406（10） A, β = 95.101（4）°, Z = 4, V = 2310.2（3） A^3, Dc = 1.513 g/cm^3, μ（MoKα） = 1.004 mm^-1, F（000） = 1088, the final R = 0.0461 and wR = 0.1048 for 2112 observed reflections （1 〉 2σ（I））.     

Synthesis of RGD-aPEG-lactoside, a Potential Anti-metastasis Glycoconjugate

The adhesive interaction between tumor cells and host cells or the extra cellular matrix plays a crucial role in metastasis. Due to the anti-metastasis effects of RGD (arginyl-glycylaspartic acid) and some oligosaccharides, RGD-aPEG-Lactoside was prepared which will be used on anti-metastasis.     

Chiral Gold(III) Complexes: Synthesis,Structure, and Potential Applications

Since the beginning of the 2000’s, homogeneous gold catalysis has emerged as a powerful tool to promote the cyclization of unsaturated substrates with excellent regioselectivity allowing the synthesis of elaborated organic scaffolds. An important goal to achieve in gold catalysis is the possibility to induce enantioselective transformations by the assistance of chiral complexes. Unfortunately, the linear geometry of coordination for gold usually encountered in complexes at the +1 oxidation states renders this goal very challenging. In consequence, the interest toward the synthesis of chiral gold(III) complexes is steadily growing. Indeed, the square planar geometry of the gold(III) cation appears more suitable to promote chiral induction. Beside catalysis, gold(III) complexes have also shown promising potential in the field of pharmacology. Herein, syntheses and applications of well-defined gold(III) complexes reported over the last fifteen years are summarized.     

A Carbazole Derivative Synthesis for Stabilizing the Quadruplex Structure

A new molecule of 3,6‐Bis(1‐methyl‐4‐vinylpyridium iodine)carbazole ( BMVC ) was synthesized for stabilizing the quadruplex structure of human telomeric sequence of d(T₂AG₃)₄ in vitro. Mixing BMVC with the DNA can raise the melting temperature of the d(T₂AG₃)₄ by ～ 13 °C, implying that BMVC could be a useful telomerase inhibitor. In addition, the fluorescence of the BMVC increased significantly upon interacting with the d(T₂AG₃)₄ which may be useful as a G‐quadruplex specific marker.     

Design and Synthesis of a Potential Dopamine D-1 Antagonist

The diastereoselective synthesis of (±)-trans-transoid-7-bromo-8-hydroxy-1-methyl-1,2,3,4,4a,5,10,10a-octahydro-10-phenylbenzo[g]quinoline ( 8 ) is described, using an intramolecular Diels-Alder reaction and a reductive cyclisation for piperidine ring-formation as key steps. Compound 8 was prepared as a putative D-1 receptor antagonist which contains (2,2-diphenylethyl)amine as a partial structure.