41 research outputs found
HPLC–QTOF–MS/MS-based rapid screening of phenolics and triterpenic acids in leaf extracts of <i>Ocimum</i> species and their interspecies variation
<p>Species of genus <i>Ocimum</i> are traditionally used for their medicinal and flavoring properties. These are rich sources of essential oils and found as an ingredient in many Ayurvedic preparations and food products. Phenolics and triterpenic acids are the medicinally active compounds mainly concentrated in the leaves of <i>Ocimum</i> species. This study aimed to develop an efficient and reliable analytical method for the rapid screening and characterization of phenolics and triterpenic acids in the leaf extracts of 6 <i>Ocimum</i> species using high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC–ESI–QTOF–MS/MS). A total of 50 compounds were identified and characterized on the basis of their accurate MS and MS/MS information, out of which 23 compounds were confirmed by authentic standards. Identified compounds include 28 flavonoids, 4 propenyl phenol derivatives, 2 triterpenic acids, 11 phenolic acids, and 5 phenolic acid esters. The developed method was applied to study the interspecies variation of identified compounds. Significant variation in the distribution of identified phenolics and triterpenic acids was observed among studied <i>Ocimum</i> species. Hence, the established method provides an effective and reliable tool for screening and characterization of phytoconstituents in <i>Ocimum</i> species.</p
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<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Table1.DOCX
<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Image3.PDF
<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Image4.PDF
<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Image2.PDF
<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Image5.PDF
<p>Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B. cenocepacia K56-2 in response to CF sputum nutritional conditions. Heterologous expression of WspR, a diguanylate cyclase, in B. cenocepacia K56-2 caused an increase in c-di-GMP levels and reduced swimming motility but did not affect flagellin expression or flagellar biosynthesis. After insertional mutagenesis of 12 putative genes encoding c-di-GMP metabolizing enzymes, one mutant of the locus BCAL1069 (cdpA), exhibited decreased swimming motility independent of flagellin expression in CF sputum nutritional conditions and an increase in intracellular c-di-GMP levels. The reduced swimming motility phenotype of the BCAL1069 mutant was observed in the presence of arginine and glutamate, but not of histidine, phenylalanine, or proline. The B. cenocepacia CdpA was also found to be involved in regulation of protease activity but not in biofilm formation. Altogether, these results highlight a role of B. cenocepacia BCAL1069 (CdpA) in sensing the nutritional conditions of the CF sputum and eliciting a pathogenic response that includes swimming motility toward amino acids and an increase in protease activity.</p
Cyanuric Chloride Catalyzed Mild Protocol for Synthesis of Biologically Active Dihydro/Spiro Quinazolinones and Quinazolinone-glycoconjugates
We have developed an efficient cyanuric chloride (2,4,6-trichloro-1,3,5-triazine,
TCT) catalyzed approach for the synthesis of 2,3-dihydroquinazolin-4(1<i>H</i>)-one (<b>3a</b>–<b>3x</b>), 2-spiroquinazolinone
(<b>5</b>, <b>7</b>), and glycoconjugates of 2,3-dihydroquinazolin-4(1<i>H</i>)-one (<b>10a</b>, <b>10b</b>) derivatives.
The reaction allows rapid cyclization (8–20 min) with 10 mol
% cyanuric chloride to give skeletal complexity in good to excellent
yield. We believe that this novel procedure may open the door for
the easy generation of new and bioactive quinazolinones
Access to Indole- And Pyrrole-Fused Diketopiperazines via Tandem Ugi-4CR/Intramolecular Cyclization and Its Regioselective Ring-Opening by Intermolecular Transamidation
An efficient approach for the synthesis of indole- and
pyrrole-fused
diketopiperazines has been developed. This protocol involves the Ugi
four-component reaction (U-4CR) followed by an intramolecular cyclization
of the Ugi products at room temperature to afford the desired products
in good to excellent yields. In addition, it is interesting to report
the subsequent regioselective ring-opening of diketopiperazine unit
occurring via an intermolecular transamidation reaction under mild
condition, resulting in the formation of highly functionalized indole-2-carboxamides
and pyrrole-2-carboxamides
Curcumin “Drug” Stabilized in Oxidovanadium(IV)-BODIPY Conjugates for Mitochondria-Targeted Photocytotoxicity
Ternary oxidovanadium(IV)
complexes of curcumin (Hcur), dipicolylamine (dpa) base, and its derivatives
having pendant noniodinated and di-iodinated boron-dipyrromethene
(BODIPY) moiety (L<sub>1</sub> and L<sub>2</sub>, respectively), namely,
[VO(dpa)(cur)]ClO<sub>4</sub> (<b>1</b>), [VO(L<sub>1</sub>)(cur)]ClO<sub>4</sub> (<b>2</b>), and [VO(L<sub>2</sub>)(cur)]ClO<sub>4</sub> (<b>3</b>) and their chloride salts (<b>1a</b>–<b>3a</b>) were prepared, characterized, and studied for anticancer
activity. The chloride salts were used for biological studies due
to their aqueous solubility. Complex <b>1</b> was structurally
characterized by single-crystal X-ray crystallography. The complex
has a VO<sup>2+</sup> moiety bound to dpa ligand showing N,N,N-coordination
in a facial mode, and curcumin is bound in its mono-anionic enolic
form. The V–O(cur) distances are 1.950(18) and 1.977(16) Å,
while the V–N bond lengths are 2.090(2), 2.130(2), and 2.290(2)
Å. The bond <i>trans</i> to VO is long due
to trans effect. The complexes are stable in a solution phase over
a long period of time of 48 h without showing any apparent degradation
of the curcumin ligand. The diiodo-BODIPY ligand (L<sub>2</sub>) or
Hcur alone showed limited solution stability in dark. The emissive
BODIPY (L<sub>1</sub>) containing complex <b>2a</b> showed preferential
mitochondrial localization in MCF-7 cells in cellular imaging experiments.
The cytotoxicity of the complexes was studied by MTT assay. The BODIPY
complex <b>3a</b> showed excellent photodynamic therapy effect
in visible light (400–700 nm) giving IC<sub>50</sub> values
of 2–6 μM in HeLa and MCF-7 cancer cells, while being
less toxic in dark (∼100 μM). The cell death was apoptotic
in nature involving reactive oxygen species (ROS). Mechanistic data
from pUC19 DNA photocleavage studies revealed photogenerated ROS as
primarily <sup>1</sup>O<sub>2</sub> from the BODIPY moiety and ·OH
radicals from the curcumin ligand