Green Synthetic Approach for Synthesis of Fluorescent Carbon Dots for Lisinopril Drug Delivery System and their Confirmations in the Cells

In this work, highly luminescent carbon dots (CDs) were synthesized by the hydrothermal method at 170 °C for 12 h using pasteurized milk as a carbon source. The prepared CDs exhibited bright blue fluorescence under UV light illumination at 365 nm. The CDs show fluorescence life time of ~4.89 ns at excitation wavelength of 370 nm. The effect of different solvents on the fluorescence property of CDs was also investigated. The lisinopril (Lis)-loaded CDs were fabricated by self-assembly of lisinopril on the surfaces of CDs, which were characterized by UV-visible and FT-IR spectroscopic techniques. The controlled release of lisinopril from the Lis-CDs was realized at pH values of 5.2, 6.2 and 7.4, respectively. The results of the cytotoxicity and confocal laser scanning microscopic images indicate that the Lis-CDs were successfully uptaken by HeLa cells without apparent cytotoxicity. The synthesized CDs show great potential as drug vehicles with good biocompatibility, sustained release of lisinopril from CDs, indicating that the CDs can act as a promising drug delivery system for therapeutic delivery and/or bioimaging applications.     

Four-component,one-pot synthesis of spiropyrazolo pyrimidine derivatives by using recyclable nanocopper ferrite catalyst and antibacterial studies

A simple, efficient, ecofriendly, and cost-effective method has been developed for the synthesis of 16 spiropyrazolo pyrimidine derivatives (5a–5p) by a four-component, one-pot reaction of pyrimidine-2,4,6(1H,3H,5H)-trione, 3-oxo-3-phenylpropanenitrile, hydrazine, and isatins (4a–4f) by using nanocopper ferrite catalyst (20?mol%) in water with excellent yields (73–91%). The isatin with electron-withdrawing groups gave products in high yields (5h and 5p). The present methodology offers an environmentally benign, cost-effective, high-yielding method with recyclable catalyst. The drug likeness or “drugability” of all the synthesized compounds were tested through rule of five (RO5) parameters. Compounds 5f, 5h, 5n, and 5p have shown one RO5 violation each. The compounds were screened for their antibacterial activity against human pathogenic bacteria wherein two of the synthesized compounds were found to possess significant antibacterial activity. Compounds showing RO5 violations had negligible antibacterial activity.     

Iron(III) acetates

Summary The compound, Fe₂CI₂(OH)₂(MeCO₂)₂ · 2MeCO₂H · H₂O, combines with lithium and silver acetates to form Fe₂Cl(OH)₂(MeCO₂)₃ · 2MeCO₂H and Fe₂(OH)₂(MeCO₂)₄ · H₂O, respectively. Iron(III)chloride in tetrahydrofuran reacts with silver acetate to give a precipitate consisting of a mixture of Fe(MeCO₂)₃ and AgCl which, when extracted with boiling acetic acid, yields     

A highly sensitive LC-MS/MS method for the determination of S-raclopride in rat plasma: application to a pharmacokinetic study in rats

A highly sensitive and rapid assay method has been developed and validated for the estimation of S‐(−)‐raclopride (S‐RCP) in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive ion mode. The assay procedure involves a simple liquid–liquid extraction technique for extraction of S‐RCP and phenacetin (internal standard, IS) from rat plasma. Chromatographic separation was achieved with 0.2% formic acid : acetonitrile (80:20, v/v) at a flow rate of 0.30 mL/min on a Phenomenex Prodigy C₁₈ column with a total run time of 4.5 min. The MS/MS ion transitions monitored were 347.2 → 112.1 for S‐RCP and 180.1 → 110.1 for IS. Method validation and pre‐clinical sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.05 ng/mL and the linearity range was extended from 0.05 to 152 ng/mL in rat plasma. The intra‐day and inter‐day precisions were 0.23–10.5 and 3.74–7.29%, respectively. This novel method was applied to a pharmacokinetic study of S‐RCP in rats. Copyright © 2010 John Wiley & Sons, Ltd.     

Immobilization of Xylanase from <Emphasis Type="Italic">Bacillus pumilus</Emphasis> Strain MK001 and its Application in Production of Xylo-oligosaccharides

Xylanase from Bacillus pumilus strain MK001 was immobilized on different matrices following varied immobilization methods. Entrapment using gelatin (GE) (40.0%), physical adsorption on chitin (CH) (35.0%), ionic binding with Q-sepharose (Q-S) (45.0%), and covalent binding with HP-20 beads (42.0%) showed the maximum xylanase immobilization efficiency. The optimum pH of immobilized xylanase shifted up to 1.0 unit (pH 7.0) as compared to free enzyme (pH 6.0). The immobilized xylanase exhibited higher pH stability (up to 28.0%) in the alkaline pH range (7.0–10.0) as compared to free enzyme. Optimum temperature of immobilized xylanase was observed to be 8 °C higher (68.0 °C) than free enzyme (60.0 °C). The free xylanase retained 50.0% activity, whereas xylanase immobilized on HP-20, Q-S, CH, and GE retained 68.0, 64.0, 58.0, and 57.0% residual activity, respectively, after 3 h of incubation at 80.0 °C. The immobilized xylanase registered marginal increase and decrease in K _m and V _max values, respectively, as compared to free enzyme. The immobilized xylanase retained up to 70.0% of its initial hydrolysis activity after seven enzyme reaction cycles. The immobilized xylanase was found to produce higher levels of high-quality xylo-oligosaccharides from birchwood xylan, indicating its potential in the nutraceutical industry.     

Magnetic moments of baryons in higher symmetry schemes including charm

Relations among the magnetic moments of charmed and uncharmed baryons are derived in the framework of SU(4) and SU(8) symmetries. The SU(3) resultμ (Σ ^o)=−μ(Λ) is not present in SU(4), but is obtained in SU(8). Higher order effects are further considered to improve the situation.     

Manifestation of up-conversion in Yb3+/Tm3+ doped Li2O–Y2O3–SiO2 glass system

In this study, we have investigated the principal role of Y₂O₃ on the emission features of Tm³⁺ ion and up-conversion phenomenon in Tm³⁺ and Yb³⁺ co-doped Li₂O–Y₂O₃–SiO₂ glass system. The concentration of Y₂O₃ is varied from 0 to 5 mol% while that of Yb³⁺ and Tm³⁺ is fixed. When the glasses are doped with Tm³⁺ ions, the intense blue and red emissions were observed, whereas Yb³⁺ doped glasses exhibited NIR emission at about 980 nm. When the glasses are co-doped with Tm³⁺ and Yb³⁺ ions and excited at 900 nm, the blue and red emission lines were observed to be reinforced and strengthened with increase in the concentration of Y₂O₃. The IR emission band detected at about 1.8 μm due to ³F₄ → ³H₆ transition of Tm³⁺ ions is also observed to be strengthened due to co-doping. The reasons for enhancement in the intensity of various emission bands due to co-doping have been identified and discussed with the help of rate equations for various emission transitions.     

Isothiazoles IX. Halogenation of 2-substituted-4-isothiazolin-3-ones

Bromination of 4-isothiazolin-3-ones, I, gave the 4-bromo derivatives, III, in good yields, while formation of 4,5-dibromo derivatives, IV, was much more difficult. In contrast, chlorination of I, even under mild conditions, gave primarily 4,5-dichloro derivatives, VI, and lesser amounts of the 4-chloro derivatives, V. Vigorous bromination of the 4-methyl analog of I gave the 5-bromo derivatives, VIII, whereas mild chlorination gave predominantly the 4,5,5-trichloro derivatives, X.     

Synthesis of indanones via solid-supported [2+2+2] cyclotrimerization

A new facile approach toward natural and unnatural indanones has been developed, featuring a solid-supported [2+2+2] cyclotrimerization as the key step. This strategy has been applied to the chemo- and regioselective assembly of indanone arrays and to the total synthesis of a recently isolated indanone marine natural product.     

Correlation between physical and structural properties of Co doped mixed alkali zinc borate glasses

The physical and structural properties of Co²⁺ doped 20ZnO + xLi₂O + (30 − x)Na₂O + 50B₂O₃ (5 ≤ × ≤ 25) (ZLNB) glasses have been studied and correlated. The physical and structural parameters of all the glasses are evaluated and a non-linear behavior is observed. No sharp peaks are observed in XRD patterns of the glass samples which confirm the amorphous nature. FT-IR spectra of ZLNB glasses reveal diborate units in borate network. The optical absorption spectra suggest the site symmetry of Co²⁺ in the glasses is near octahedral. Crystal field and inter-electronic repulsion parameters are also evaluated. The optical band gap and Urbach energies exhibit the mixed alkali effect. All the samples are found to be strong and stable in structure with low values of Urbach energy which lie between 0.027 eV and 0.039 eV. The correlation between densities and Urbach energies of Co²⁺ doped ZLNB glasses with respect to Li₂O content suggest a changeover conduction mechanism from electronic to ionic, with a diffusivity crossover point at x = 15 mol%.