Selective Hg²⁺ Sensing Behaviors of Rhodamine Derivatives with Extended Conjugation Based on Two Successive Ring-Opening Processes

A novel class of rhodamine derivatives with two spirolactam moieties have been synthesized, and their two stereoisomers of <i>cis</i>- and <i>trans</i>-forms have been successfully separated and isolated, as well as structurally characterized by X-ray crystallography. Attributed to the successive ring-openings of two spirolactam moieties, different solution color, electronic absorption and emission responses were exhibited upon addition of various concentrations of mercury­(II) ion. Arising from two successive ring-opening processes in the presence of various concentration of Hg­(II) ion, two reporting states with different spectroscopic properties were suggested, that is, the first state showing pink color (absorption maximum at 496 nm) but no emission, while the second state giving purple color (absorption maximum at 593 nm) and red emission (emission maximum at 620 nm). The mechanism of such different spectroscopic responses was also proposed and has also been supported by computational studies. An extension of the present work to the study of the corresponding chemodosimeters from the compounds with two spirolactam groups has been made, in which a stoichiometric and irreversible Hg­(II)-promoted reaction of thiosemicarbazides was utilized to form 1,3,4-oxadiazoles

Comprehensive and Quantitative Analysis of Lysophospholipid Molecular Species Present in Obese Mouse Liver by Shotgun Lipidomics

Shotgun lipidomics exploits the unique chemical and physical properties of lipid classes and individual molecular species to facilitate the high-throughput analysis of a cellular lipidome on a large scale directly from the extracts of biological samples. A platform for comprehensive analysis of lysophospholipid (LPL) species based on shotgun lipidomics has not been established. Herein, after extensive characterization of the fragmentation pattern of individual LPL class and optimization of all experimental conditions including developing new methods for optimization of collision energy, and recovery and enrichment of LPL classes from the aqueous phase after solvent extraction, a new method for comprehensive and quantitative analysis of LPL species was developed. This newly developed method was applied for comprehensive analysis of LPL species present in mouse liver samples. Remarkably, the study revealed significant accumulation of LPL species in the liver of ob/ob mice. Taken together, by exploiting the principles of shotgun lipidomics in combination with a novel strategy of sample preparation, LPL species present in biological samples can be determined by the established method. We believe that this development is significant and useful for understanding the pathways of phospholipid metabolism and for elucidating the role of LPL species in signal transduction and other biological functions

Selective Hg²⁺ Sensing Behaviors of Rhodamine Derivatives with Extended Conjugation Based on Two Successive Ring-Opening Processes

A novel class of rhodamine derivatives with two spirolactam moieties have been synthesized, and their two stereoisomers of <i>cis</i>- and <i>trans</i>-forms have been successfully separated and isolated, as well as structurally characterized by X-ray crystallography. Attributed to the successive ring-openings of two spirolactam moieties, different solution color, electronic absorption and emission responses were exhibited upon addition of various concentrations of mercury­(II) ion. Arising from two successive ring-opening processes in the presence of various concentration of Hg­(II) ion, two reporting states with different spectroscopic properties were suggested, that is, the first state showing pink color (absorption maximum at 496 nm) but no emission, while the second state giving purple color (absorption maximum at 593 nm) and red emission (emission maximum at 620 nm). The mechanism of such different spectroscopic responses was also proposed and has also been supported by computational studies. An extension of the present work to the study of the corresponding chemodosimeters from the compounds with two spirolactam groups has been made, in which a stoichiometric and irreversible Hg­(II)-promoted reaction of thiosemicarbazides was utilized to form 1,3,4-oxadiazoles

Selective Hg²⁺ Sensing Behaviors of Rhodamine Derivatives with Extended Conjugation Based on Two Successive Ring-Opening Processes

A novel class of rhodamine derivatives with two spirolactam moieties have been synthesized, and their two stereoisomers of <i>cis</i>- and <i>trans</i>-forms have been successfully separated and isolated, as well as structurally characterized by X-ray crystallography. Attributed to the successive ring-openings of two spirolactam moieties, different solution color, electronic absorption and emission responses were exhibited upon addition of various concentrations of mercury­(II) ion. Arising from two successive ring-opening processes in the presence of various concentration of Hg­(II) ion, two reporting states with different spectroscopic properties were suggested, that is, the first state showing pink color (absorption maximum at 496 nm) but no emission, while the second state giving purple color (absorption maximum at 593 nm) and red emission (emission maximum at 620 nm). The mechanism of such different spectroscopic responses was also proposed and has also been supported by computational studies. An extension of the present work to the study of the corresponding chemodosimeters from the compounds with two spirolactam groups has been made, in which a stoichiometric and irreversible Hg­(II)-promoted reaction of thiosemicarbazides was utilized to form 1,3,4-oxadiazoles

Selective Hg²⁺ Sensing Behaviors of Rhodamine Derivatives with Extended Conjugation Based on Two Successive Ring-Opening Processes

A novel class of rhodamine derivatives with two spirolactam moieties have been synthesized, and their two stereoisomers of <i>cis</i>- and <i>trans</i>-forms have been successfully separated and isolated, as well as structurally characterized by X-ray crystallography. Attributed to the successive ring-openings of two spirolactam moieties, different solution color, electronic absorption and emission responses were exhibited upon addition of various concentrations of mercury­(II) ion. Arising from two successive ring-opening processes in the presence of various concentration of Hg­(II) ion, two reporting states with different spectroscopic properties were suggested, that is, the first state showing pink color (absorption maximum at 496 nm) but no emission, while the second state giving purple color (absorption maximum at 593 nm) and red emission (emission maximum at 620 nm). The mechanism of such different spectroscopic responses was also proposed and has also been supported by computational studies. An extension of the present work to the study of the corresponding chemodosimeters from the compounds with two spirolactam groups has been made, in which a stoichiometric and irreversible Hg­(II)-promoted reaction of thiosemicarbazides was utilized to form 1,3,4-oxadiazoles

Changes in the SOM composition along the grazing-exclusion grassland chronosequence.

<p>^† GE0, free grazing; GE4, 4-year grazing exclusion; GE7, 7-year grazing exclusion; GE11, 11-year grazing exclusion; GE31, 31-year grazing exclusion.</p><p>^‡ HAC, Humic acid carbon; FAC, Fulvic acid carbon; HUC, Humin carbon; Extractable humus C, Extractable humus carbon;HAC/FAC, The ratio of humic acid carbon to fulvic acid carbon; HAC/extractable humus C, The ratio of humic acid carbon to extractable humus carbon.</p><p>^§ Data were represented as mean ± SD (n = 3). The same superscript letters within each column indicated no significant difference at <i>P</i> < 0.05.</p><p>Changes in the SOM composition along the grazing-exclusion grassland chronosequence.</p

Relative distribution (%) of organic carbon in HA by ¹³C CPMAS NMR.

<p>^† GE0, free grazing; GE4, 4-year grazing exclusion; GE7, 7-year grazing exclusion; GE11, 11-year grazing exclusion; GE31, 31-year grazing exclusion.</p><p>^‡ Aromaticity = Aromatic C/(Alkyl C+O-alkyl C+Aromatic C)×100%.</p><p>^§Hydrophobicity = (Alkyl C + Aromatic C)/(O-alkyl C + Carbonyl C).</p><p>Relative distribution (%) of organic carbon in HA by ¹³C CPMAS NMR.</p

Relationships between soil organic carbon (SOC), humic acid carbon (HAC), fulvic acid carbon (FAC), humic acid carbon (HUC), HAC/FAC, HAC/extractable humus carbon with the duration of grazing exclusion.

<p>Relationships between soil organic carbon (SOC), humic acid carbon (HAC), fulvic acid carbon (FAC), humic acid carbon (HUC), HAC/FAC, HAC/extractable humus carbon with the duration of grazing exclusion.</p

Changes in the selected soil properties in the grazing-exclusion grassland chronosequence.

<p>^† GE0, free grazing; GE4, 4-year grazing exclusion; GE7, 7-year grazing exclusion; GE11, 11-year grazing exclusion; GE31, 31-year grazing exclusion.</p><p>^‡ SOC, soil organic carbon; TN, Soil total nitrogen; TP, Soil total phosphorus.</p><p>^§ Data were represented as mean ± SD (n = 4). The same superscript letters within each column indicated no significant difference at <i>P</i> < 0.05.</p><p>Changes in the selected soil properties in the grazing-exclusion grassland chronosequence.</p

Solid-state¹³C CPMAS NMR spectra for humic acid (HA) under grazing-exclusion grassland chronosequence.

<p>Solid-state¹³C CPMAS NMR spectra for humic acid (HA) under grazing-exclusion grassland chronosequence.</p