Concise syntheses of 2-aminoindans via indan-2-ol

2-Amino-5,6-dimethoxyindan hydrochloride was synthesized in seven steps and with an overall yield of 48%. Indan-2-ol was converted to 5,6-dibromo-indan-2-ol in three steps by acetylation, electrophilic bromination and deacetylation. Dimethoxylation of 5,6-dibromoindan-2-ol with NaOCH₃ in the presence of CuI gave 5,6-dimethoxy-indan-2-ol, which was converted to 2-amino-5,6-dimethoxyindan hydrochloride by azidation, followed by Pd-C catalyzed hydrogenation. Similarly, 2-amino-5-bromoindan was synthesized in five steps and with an overall yield of 50%. Indan-2-ol was converted to 2-aminoindan by azidation followed by Pd-C catalyzed hydrogenation. The reaction of 2-aminoindan with 2.5 equiv Br₂ afforded 2-amino-5,6-dibromoindan.     

The effects of aggregation, protein binding and cellular incorporation on the photophysical properties of benzoporphyrin derivative monoacid ring A (BPDMA)

Absorption, fluorescence and laser flash photolysis spectroscopies were used to investigate the effects of self-aggregation, binding to human serum albumin and incorporation in cancer cells on the photophysics of benzoporphyrin derivative monoacid ring A (BPDMA). Aggregation of BPDMA has been studied in mixtures of methanol and phosphate-buffered saline (PBS). The extent of aggregation was dependent on dye concentration and solvent composition, becoming particularly marked in mixtures containing less than 30% methanol. A dimerization constant K_d or 9 × 10⁶ M⁻¹ was determined by fluorescence experiments for BPDMA in pure PBS. In addition to spectral modifications, aggregation induces a lowering of the fluorescence and intersystem crossing quantum yields. Human serum albumin binds BPDMA with an association constant K_b of 5.2 × 10⁵ M⁻¹ in PBS. When bound to HSA, BPDMA displays photophysical properties very similar to the monomer in organic solvents. The molar ratio [HSA]/[BPDMA] corresponding to complete binding of the dye was determined to be approximately 10. Efficient generation of the triplet state of BPDMA was also observed from aqueous cellular suspensions containing incorporated photosensitizer.     

Improved conditions for measurement of the specific heat capacities of pure triglycerides by differential scanning calorimetry

Reproducible specific heat capacities (C _p) of triglycerides can be obtained by using heat-flux DSC under improved operating conditions. The improved operating parameters, such as the scanning rate, the sample mass and the atmosphere within the DSC chamber, were established via statistical analysis of the experimental data with trilaurin as a sample. The specific heat capacity results on trilaurin were compared with the values calculated by using estimation methods. The precision of the specific heat capacity measured for trilaurin under these conditions was within ±1%.     

A simple synthesis of 5‐ethoxycarbonyl‐6‐phenyl‐1,3‐dioxin‐4‐ones and ethyl 3‐benzoyl‐4‐oxo‐2,6‐diphenylpyran‐5‐carboxylate

4‐Ethoxycarbonyl‐5‐phenyl‐2,3‐dihydrofuran‐2,3‐dione 1 reacts with aldehydes via the acylketene intermediate 2 giving the 1,3‐dioxin‐4‐ones 3a‐e and the 1,4‐bis(5‐ethoxycarbonyl‐4‐oxo‐6‐phenyl‐4H‐1,3‐dioxin‐2‐yl)benzene 4 , and a one step reaction between dibenzoylmethane and oxalylchloride gave 3,5‐dibenzoyl‐2,6‐diphenyl‐4‐pyrone 7 . The reaction of 1 with dibenzoylmethane, a dicarbonyl compound, provided ethyl 3‐benzoyl‐4‐oxo‐2,6‐diphenylpyran‐5‐carboxylate derivative 9 . Compound 9 was converted into the corresponding ethyl 3‐benzoyl‐4‐hydroxy‐2,6‐diphenylpyridine‐5‐carboxylate derivative 10 via its reaction with ammonium hydroxyde solution in 1 ‐butanol.     

N-acetyl-beta-D-glucosaminidase in acute myocardial infarction

The objective of the study was to investigate whether the lysosomal enzyme, N-Acetyl-beta-D-glucosaminidase (NAG) activity is increased in plasma of patients with acute myocardial infarction (AMI) and to determine if there is any association between plasma levels of NAG and severity of myocardial infarction (MI). NAG activity in plasma was monitored in 69 patients with AMI and 135 normal healthy subjects using a spectrofluorimetric method. A modified Aldrich ST elevation score was used to gauge the severity of MI in terms of size of the infarct. Plasma NAG levels in AMI patients and normal healthy subjects were found to be 10.92+/-7.5 U/l and 6.8+/-2.2 U/l, respectively. These two mean value when compared by Student's t-test were significantly different P = 0.0001. No statistically significant differences in NAG activity were observed in patients in terms of gender, age, location of infarct, time from onset of chest pain to blood sampling in the hospital and size of the infarct.     

Synthesis and microwave‐assisted catalytic activity of novel bis‐benzimidazole salts bearing furfuryl and thenyl moieties in Heck and Suzuki cross‐coupling reactions

A mixture of bis‐benzimidazole salts ( 1–7 ), Pd(OAc)₂ and K₂CO₃ in DMF ? H₂O catalyzes, in high yield, the Suzuki and Heck cross‐coupling reactions assisted by microwave irradiation in a short time. In particular, the yields of the Heck and Suzuki reactions with aryl bromides were found to be nearly quantative. The synthesized bis‐benzimidazole salts ( 1 – 7 ) were identified by ¹H? ¹³C NMR, IR spectroscopic methods and micro analysis. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and Crystal Structure of Trans-bis(acesulfamato-O)tetraaquazinc(Ⅱ)

<正>The title compound,trans-bis(acesulfamato-O)tetraaquazinc(Ⅱ)(I,C_8H_(16)N_2O_(12)S_2Zn), crystallizes in the triclinic system,space group P_1~-with a=5.1638(5),b=8.5338(9),c=9.9583(9) (?),a=74.325(8),β=81.112(7),γ=75.800(8)°,V=407.77(7)(?)~3,Z=1,F(000)=236,R_(int)=0.085, T=296 K,the final R=0.029 and wR=0.078 for 1832 observed reflections with I2σ(I).The Zn~Ⅱcentre resides on a centre of symmetry and has a distorted octahedral geometry.The basal plane is defined by two carbonyl O atoms of two monodentate trans-oriented acesulfamato ligands and two trans-aqua ligands.The axial positions in the octahedron are occupied by two trans-aqua ligands. Intermolecular O-H…O hydrogen bonds produce R_2~2(8)and R_2~2(16)rings,which lead to two-dimensional polymeric chains.     

Interactions of thioflavin T with serum albumins: Spectroscopic analyses

The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant (K) for HSA was found to be 9.9 × 10⁴ M⁻¹, 4.3 × 10⁴ M⁻¹ for RSA, 1.07 × 10⁴ M⁻¹ for PSA and 0.3 × 10⁴ M⁻¹ for BSA and the number of binding sites (n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. ΔG_binding, ΔH and ΔS were calculated to be −28.46 kJ mol⁻¹, −3.50 kJ mol⁻¹ and 81.04 J K⁻¹ mol⁻¹, respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.     

Phenylethyl Glycosides from Digitalis lanata

Three new phenylethyl glycosides, 3′′′′‐O‐methylmaxoside (=2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→6)]‐4‐O‐(E)‐feruloyl‐β‐D ‐glucopyranoside; 1 ), digilanatosides A (=2‐(3,4‐dihydroxyphenyl)ethyl O‐6‐O‐(E)‐sinapoyl‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐(E)‐caffeoyl‐β‐D ‐glucopyranoside; 2 ), and digilanatoside B (=2‐(3,4‐dihydroxyphenyl)ethyl O‐6‐O‐(E)‐p‐coumaroyl‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐(E)‐caffeoyl‐β‐D ‐glucopyranoside; 3 ) were isolated from the aerial parts of Digitalis lanata, along with two known phenylethyl glycosides, purpureaside A and maxoside, a phenylpropanoid glucose ester, 1‐O‐(E)‐feruloyl‐β‐glucopyranose, a benzoquinolethanoid glucoside, cornoside, a cardenolide, lanatoside C, a furostane‐type steroidal saponin, purpureagitoside, and a disaccharide, sucrose. Their structures were elucidated on the basis of spectroscopic evidence (1D‐ and 2D‐NMR, and HR‐MALDI‐MS).