Rhazimine - a new alkaloid from the leaves of rhazya stricta

Studies on the alkaloids in the leaves of Rhazya stricta have resulted in the isolation of a new alkaloid “rhazimine” (2) bearing a novel skeletal system closely related to the ajmaline group of alkaloids.     

New Quinoxaline Derivatives as Dual Pim-1/2 Kinase Inhibitors: Design,Synthesis and Biological Evaluation

Proviral integration site for Moloney murine leukemia virus (Pim)-1/2 kinase overexpression has been identified in a variety of hematologic (e.g., multiple myeloma or acute myeloid leukemia (AML)) and solid (e.g., colorectal carcinoma) tumors, playing a key role in cancer progression, metastasis, and drug resistance, and is linked to poor prognosis. These kinases are thus considered interesting targets in oncology. We report herein the design, synthesis, structure–activity relationships (SAR) and in vitro evaluations of new quinoxaline derivatives, acting as dual Pim1/2 inhibitors. Two lead compounds (5c and 5e) were then identified, as potent submicromolar Pim-1 and Pim-2 inhibitors. These molecules were also able to inhibit the growth of the two human cell lines, MV4-11 (AML) and HCT-116 (colorectal carcinoma), expressing high endogenous levels of Pim-1/2 kinases.     

Comparative study of spectroscopic techniques for the estimation of iron in apple and vegetables

Iron has been determined in apple and vegetables spectrophotometrically, by complexing it with xylenol orange. 1:1 complex formed in a highly acidic medium is measured for its absorbance at its λ_max of 585 nm. The results have been compared by employing atomic absorption technique. Apples and vegetable samples were collected from local markets of Pakistan. Statistical manipulations, t-test and F-test, were performed and it was found that the results from the two techniques have an excellent agreement.     

Diffraction of love waves by two staggered perfectly weak half-planes

Summary Love wave travelling in a layer of uniform thickness overlying a half-space is assumed to be incident on two parallel but staggered perfectly weak half-planes lying in the upper layer. The diffracted field is calculated using the modified Wiener-Hopf technique and contour integration method. The diffracted waves satisfy the dispersion relations appropriate to different regions formed by the perfectly weak half-planes. To the memory of M. H. Kazi     

On virtual pathwidth of virtual graphs of a virtual link

The geometric representation of a knot is not too dissimilar from a graph and this interaction has helped mathematicians to solve many problems. In this paper, we apply graph theory tools to study the classification of virtual knots and links. We define virtual planar graphs and compute virtual path width of an associated graph of a virtual link. We show that the virtual path width of an associated graph is equal to the virtual bridge number of a pseudo prime knot.     

Purification and biochemical characterisation of acid phosphatase-I from seeds of Nelumbo nucifera

Acid phosphatase-I (Apase-I) from seeds of Nelumbo nucifera was purified to electrophoretic homogeneity by combination of ammonium sulfate precipitation, size-exclusion and ion exchange chromatography. SDS-PAGE of purified Apase-I gave a single band with molecular mass of 80 kDa under reducing and non-reducing conditions, indicating that the enzyme was a monomer. The purified enzyme showed maximum activity at 50°C and at pH 5. The Km, Vmax and Kcat for p-nitrophenyl phosphate were 132 μM, 10 μmol/min/mg and 6.7/sec respectively. Apase-I activity was strongly inhibited by Zn²⁺, W²⁺; weakly inhibited by Cu²⁺, Mo²⁺ and Cr⁶⁺ and moderately activated by Mg²⁺. The enzyme was shown to be thermolabile as it lost 50% of its activity at 50°C after incubation for 1 hour. The amino acid analysis of enzyme revealed high proportion of acidic amino acids, which is very similar to that of tomato Apase-I and lower than potato Apase.     

Efficient Low-Cost Procedure for Microextraction of Estrogen from Environmental Water Using Magnetic Ionic Liquids

In this study, three magnetic ionic liquids (MILs) were investigated for extraction of four estrogens, i.e., estrone (E1), estradiol (E2), estriol (E3), and ethinylestradiol (EE2), from environmental water. The cation trihexyl(tetradecyl)phosphonium ([P₆₆₆₁₄]⁺), selected to confer hydrophobicity to the resulting MIL, was combined with tetrachloroferrate(III), ferricyanide, and dysprosium thiocyanate to yield ([P₆₆₆₁₄][FeCl₄]), ([P₆₆₆₁₄]₃[Fe(CN)₆]), and ([P₆₆₆₁₄]₅[Dy(SCN)₈]), respectively. After evaluation of various strategies to develop a liquid–liquid microextraction technique based on synthesized MILs, we placed the MILs onto a magnetic stir bar and used them as extracting solvents. After extraction, the MIL-enriched phase was dissolved in methanol and injected into an HPLC–UV for qualitative and quantitative analysis. An experimental design was used to simultaneously evaluate the effect of select variables and optimization of extraction conditions to maximize the recovery of the analytes. Under optimum conditions, limits of detection were in the range of 0.2 (for E3 and E2) and 0.5 μg L⁻¹ (for E1), and calibration curves exhibited linearity in the range of 1–1000 μg L⁻¹ with correlation coefficients higher than 0.998. The percent relative standard deviation (RSD) was below 5.0%. Finally, this method was used to determine concentration of estrogens in real lake and sewage water samples.     

2,2′‐(Ethane‐1,2‐diyl)bis[2‐(5‐bromothiophen‐2‐yl)‐1,3‐dioxolane] at 100 K refined using a multipolar atom model

The title compound, C₁₆H₁₆Br₂O₄S₂, which is a precursor for the synthesis of oligothiophenes and their substituted homologues, was synthesized and its X‐ray crystal structure determined at 100 K. The experimental electron‐density parameters for the available atom types were transferred from the ELMAM2 database. The compound lies about an inversion centre, which coincides with the mid‐point of a C—C bond. The molecules in the crystal are linked by several types of weak interactions; the largest contact surfaces are for H...H and H...Br.     

Strong π-delocalization and substitution effect on electronic properties of dithienylpyrrole-containing bipyridine ligands and corresponding ruthenium complexes

The first dithienylpyrrole (DTP)-based bipyridine ligands has been prepared and coordinated with ruthenium to give the corresponding homoleptic complexes. Bipyridine was bound at pyrrole (DTP(1)) or thiophene (DTP(2)) ring. A strong bathochromic effect was obtained by switching from pyrrole to thiophene for ligands and complexes. Interestingly the DTP(2) series offered a wide absorption window from UV to visible domain with an almost constant absorbance. These effects are due to a larger extent of delocalization as supported by DFT calculations and photophysical measurements.