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1.
Two-Photon-Induced CO-Releasing Molecules as Molecular Logic Systems in Solution,Polymers, and Cells
Dr. Vadde Ramu Dr. Gandra Upendar Reddy Dr. Jingjing Liu Patrick Hoffmann Dr. Rudrakant Sollapur Dr. Ralf Wyrwa Dr. Stephan Kupfer Prof. Dr. Christian Spielmann Dr. Sylvestre Bonnet Prof. Dr. Ute Neugebauer Dr. Alexander Schiller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8453-8458
Phototherapeutic applications of carbon monoxide (CO)-releasing molecules are limited because they require harmful UV and blue light for activation. We describe two-photon excitation with NIR light (800 nm)-induced CO-release from two MnI tricarbonyl complexes bearing 1,8-naphthalimide units ( 1 , 2 ). Complex 2 behaves as a logic OR gate in solution, nonwovens, and in HeLa cells. CO release, indicated by fluorescence enhancement, was detected in solution, nonwoven, and HeLa cells by single- (405 nm) and two-photon (800 nm) excitation. The photophysical properties of 1 and 2 have been measured and supported by DFT and TDDFT quantum chemical calculations. Both photoCORMs are stable in the dark in solution and noncytotoxic, leading to promising applications as phototherapeutics with NIR light. 相似文献
2.
A series of novel 3-[5-(1H-indol-3-yl-methyl)-2-oxo-[1,3,4]oxadiazol-3-yl]propionitrile(5),3-[4- amino-3-(1H-indol-3-yl-methyl)-5-oxo-4,5-dihydro-[1,2.4]triazol-1-yljpropionitrile(6),3-[5-(1H- indol-3-yl-methyl)-2-thioxo-[1,3,4]oxadiazol-3-yl]propionitrile(7) and 3-[4-amino-3-(1H-indol-3-yl-methyl) -5-thioxo-4,5-dihydro-[1,2,4]triazol-l -yljpropionitrile(8) were synthesized in good yields from the intermediate(1H-indol-3-yl)-acetic acid N’-(2-cyanoethyl)hydrazide(4).The chemical structures of the newly synthesized compounds were elucidated by their IR,~1H NMR and MS.Further,all the compounds were screened for their antimicrobial activity against Gram-positive,Gram-negative bacteria and also tested their ability toward anti-inflammatory activity. 相似文献
3.
Mallikarjun Reddy Sura Vasu Govardhana Reddy Peddiahgari Rajendra Prasad Reddy Bhoomireddy Rama Krishna Vadde 《Journal of heterocyclic chemistry》2013,50(6):1395-1399
A new series of 2,4‐diaryl‐6‐methyl‐5‐nitropyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i ) were synthesized in good yields by Suzuki–Miyaura coupling of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 3 ) with various aryl boronic esters ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i ) in the presence of 1,1′‐ bis(diphenylphosphino)ferrocene dichloropalladium(II) (Pd(dppf)2Cl2). Further, antibacterial and antioxidant properties were screened for the title compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i . Most of the compounds possessed significant activity against Gram‐positive bacteria Staphylococcus aureus and Bacillus subtilis and Gram‐negative bacteria Escherichia coli and Klebsiella pneumoniae. The antioxidant activity of the title compounds showed significant antioxidant activity when compared with vitamin C. 相似文献
4.
A first example of organo-N-heterocyclic carbene (NHC) catalyzed click-type fast 1,3-dipolar cycloaddition of nitrile oxides with alkynes was developed for the regioselective synthesis of 3,5-di- and 3,4,5-trisubstituted isoxazoles. Triethylamine (Et(3)N) was employed as an effective base to generate both nitrile oxide and the organo-NHC catalyst in situ. This catalytic approach was used to attach a variety of substituents, including other biologically active fragments, onto the isoxazole ring to selectively design multinucleus structures. Further, we have also optimized the conditions for Cu(I)-free Sonogashira cross-coupling to obtain internal alkynes in high yields, which were subsequently used in cycloaddition. A catalytic cycle is proposed and the remarkable regiocontrol in the formation of isoxazoles was ascribed to a beneficial zwitterion intermediate developed by the interaction of the strongly nucleophilic organo-NHC catalyst with alkyne followed by nitrile oxide. 相似文献
5.
A new cloud vapor zone (CVZ)-based headspace solid-phase microextraction (HS-SPME) technique has been demonstrated with the
capability of heating the sample matrix and simultaneously cooling the sampling zone. A bi-temperature-controlled (BTC) system,
allowing 10 mL of test sample heating and headspace external-cooling, was employed for the CVZ formation around the SPME-fiber
sampling area. In the CVZ procedure, the heated headspace vapor undergoes a sudden cooling near the SPME to form a dense cloud
of analyte–water vapor, which is helpful for adsorption or absorption of the analyte. The device was evaluated for the quantitative
analysis of aqueous chlorothalonil. Parameters influencing sampling efficiency, e.g., SPME fiber coating, SPME sampling temperature
and time, solution modifier, addition of salt, sample pH, and temperature, were investigated and optimized thoroughly. The
proposed BTC-HS-SPME method afforded a best extraction efficiency of above 94% accuracy (less than 4.1% RSD, n = 7) by using the PDMS fiber to collect chlorothalonil in the headspace at 5 °C under the optimized condition, i.e., heating
sample solution (added as 10% ethylene glycol and 30% NaCl, at pH 7.0) at 130 °C for 15 min. The detection was linear from
0.01 to 80 μg L−1 with a regression coefficient of 0.9998 and had a detection limit of 3.0 ng L−1 based on S/N = 3. Practical application was demonstrated by analyzing chlorothalonil in farm water samples with promising
results and recoveries. The approach provided a very simple, fast, sensitive, and solvent-free procedure to collect analytes
from aqueous solution. The approach can provide a new platform for other sensitive HS-SPME assays. 相似文献
6.
M. Arjun D. Sridhar M. Adharvana Chari M. Sarangapani 《Journal of heterocyclic chemistry》2009,46(1):119-123
7.
P. Muralidhar Reddy Adapa V. S. S. Prasad Vadde Ravinder 《Transition Metal Chemistry》2007,32(4):507-513
Macrocyclic CuII compounds of the type Cu(L4)Cl2 (where L4 = N4 or N2O2 donor macrocyclic ligand) have been synthesized by treating the corresponding macrocycles with copper chloride in methanol.
These compounds were characterized with the help of elemental analysis, i.r., mass, ESR, electronic spectra, conductance,
magnetic and thermal studies. Distorted octahedral geometry has been proposed for all of these compounds. These compounds
were found to be efficient in the catalytic oxidation of ascorbic acid and the percentage yields of oxidation products were
determined spectrophotometrically. The biological activities of these compounds have been tested against gram +ve and gram
−ve bacteria and found to be more active when compared with commercially available antibacterials like streptomycin and ampicillin. 相似文献
8.
Vadde Ramakrishna Sake Rajasekhar Lokireddy Sudarsana Reddy 《Applied biochemistry and biotechnology》2010,160(1):63-71
Proteolytic enzymes play a central role in the biochemical mechanism of germination. The present study reported the presence
of Zn2+-dependent endoproteases in the dry seeds of grass pea (Lathyrus sativus L.) with maximum caseinolytic activity observed at pH 8.0. Studies with class-specific inhibitors (specific for cysteine,
serine, aspartate, and metalloproteases) on crude extract identified the inhibitory effect of 1,10-phenanthroline. This inhibitory
effect was overcome by addition of Zn2+, not with Fe, Ca, Cu, Mg, or Co and indicates that the protease is Zn2+ dependent. This metalloprotease was further characterized by attempting gelatin-PAGE zymography and observed three distinct
zones of proteolytic activity with higher mobility. The protease fraction consisted of three isoforms as evidenced by the
appearance of three different bands on gelatin-PAGE zymogram. We also purified these proteases to 110-fold by a three-step
procedure comprising crude extract from dry seeds, (NH4)2SO4 fractionation, and casein–alginate affinity chromatography. The molecular mass of isoforms of metalloproteases is 25, 18,
and 14 kDa. 相似文献
9.
Vadde Ravinder S. Ashok A. V. S. S. Prasad G. Balaswamy Y. Ravindra Kumar B. Vijaya Bhaskar 《Chromatographia》2008,67(3-4):331-334
A rapid isocratic chiral HPLC method has been developed for the separation of R-galantamine from S-galantamine. Good resolution viz. Rs > 3 between R- and S- forms of galantamine was achieved with chiralpak AD-H (250 × 4.6 mm) column using n-hexane, 20% propionic acid in isopropanol and diethyl amine in the ratio of 80:20:0.2 (v/v) as mobile phase at ambient temperature. Flow rate was kept as 0.8 mL min−1 and the elution was monitored at 289 nm. This method was further used to determine the amount of R-galantamine in pure and pharmaceutical formulations of S-galantamine. This method is capable to detect and quantitate R-galantamine to the levels of 0.21 and 0.84 μg mL−1, respectively. The method was validated as per International Conference on Harmonization (ICH) guidelines in terms of limit
of detection (LOD), limit of quantification (LOQ), linearity, precision, accuracy, specificity, robustness and ruggedness. 相似文献
10.
Hoffman PD Sarangapani PS Zhu Y 《Langmuir : the ACS journal of surfaces and colloids》2008,24(21):12164-12171
Dielectrophoretic behaviors and assembly of a binary suspension in aqueous media are examined in the presence of nonuniform alternating current (AC) electric field. A peculiar low-frequency threshold and dielectrophoresis (DEP) crossover frequency determine the applicable frequency window for binary assembly under positive DEP, which can be effectively tuned by medium conductivity and particle size, suggesting that the dynamic double-layer effect is responsible for the interfacial polarization of micrometer to submicrometer-sized particles in aqueous suspensions. Strong effects of AC-field frequency, medium conductivity, and size ratio on binary assembly morphology have been observed. A frequency-medium conductivity phase diagram is obtained to illustrate the morphological transition of assembled colloidal aggregates from segregated, ordered assemblies to inverted segregation with the appearance of amorphous phases upon increasing frequency and/or medium conductivity, which is a direct consequence of the competition between DEP and hydrodynamic mobility. Significantly, our results demonstrate a rapid method to form hybrid nanostructured materials. 相似文献