Multiphoton-excited dynamics of the trans or cis structural isomer of 1,2-dibromoethylene

2021 ◽  
Author(s):  
Junggil Kim ◽  
Sang Kyu Kim
Keyword(s):  
Structural Isomer

Two isoprenylated flavonoids from Dorstenia psilurus activate AMPK, stimulate glucose uptake, inhibit glucose production and lower glycemia

2019 ◽  
Vol 476 (24) ◽  
pp. 3687-3704 ◽  
Author(s):  
Aphrodite T. Choumessi ◽  
Manuel Johanns ◽  
Claire Beaufay ◽  
Marie-France Herent ◽  
Vincent Stroobant ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Human Cancer ◽  
Glucose Production ◽  
Liver Mitochondria ◽  
New Drugs ◽  
Structural Isomer ◽  
Rat Liver Mitochondria ◽  
Ionization Mass ◽  
Ampk Activation ◽  
Starting Point

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze–thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1−/− mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.

Theoretical study on the formation of carbon disulfide and ammonia from thermal decomposition products of thiourea

2014 ◽  
Vol 13 (04) ◽  
pp. 1450022 ◽  
Author(s):  
Zerong Daniel Wang ◽  
Meagan Hysmith ◽  
Perla Cristina Quintana
Keyword(s):  
Thermal Decomposition ◽  
Carbon Disulfide ◽  
Density Functional ◽  
Basis Sets ◽  
Structural Isomer ◽  
Consecutive Reaction ◽  
Functional Theory ◽  
Decomposition Products ◽  
Thermal Decomposition Products ◽  
Hybrid Module

The formation of carbon disulfide ( CS 2) and ammonia ( NH 3) from the thermal decomposition products of thiourea has been studied with MP2, and hybrid module-based density functional theory methods (B3LYP, MPW1PW91 and PBE1PBE), each in conjunction with five different basis sets (6-31+G(2d,2p), 6-311++G(2d,2p), DGDZVP, DGDZVP2 and DGTZVP). The free energy changes and activation energies for all the five primitive reactions involved in the formation of CS 2 and NH 3 have been compared and discussed. The results indicate that CS 2 is most likely formed in a consecutive reaction path that consists of the addition of hydrogen sulfide ( H 2 S ) to isothiocyanic acid (HNCS) to generate carbamodithioic acid and subsequent decomposition of carbamodithioic acid. By contrast, thiocyanic acid (HSCN) as the structural isomer of isothiocyanic acid is not likely the source of CS 2.

scholarly journals Synthesis of a Structural Isomer of Actinidine from Citronellonitrile

1971 ◽  
Vol 92 (6) ◽  
pp. 548-551 ◽  
Author(s):  
Yasuo BUTSUGAN ◽  
Shigeo YOSHIDA ◽  
Masao MUTO ◽  
Tadaaki BITO ◽  
Teruo MATSUURA ◽  
...  
Keyword(s):  
Structural Isomer

Fabrication and characterization of collagen–hydroxyapatite-based composite scaffolds containing doxycycline via freeze-casting method for bone tissue engineering

2018 ◽  
Vol 33 (4) ◽  
pp. 501-513 ◽  
Author(s):  
Hossein Semyari ◽  
Majid Salehi ◽  
Ferial Taleghani ◽  
Arian Ehterami ◽  
Farshid Bastami ◽  
...  
Keyword(s):  
Cellular Response ◽  
Composite Scaffold ◽  
Precipitation Method ◽  
Structural Isomer ◽  
Freeze Casting ◽  
Hydroxyapatite Nanoparticles ◽  
Casting Method ◽  
Defect Model ◽  
Co Precipitation

In this study, hydroxyapatite nanoparticles containing 10% doxycycline, a structural isomer of tetracycline, was prepared by the co-precipitation method. It was added to collagen solution for the preparation of the scaffold with freeze-casting method in order to develop a composite scaffold with both antibacterial and osteoinductive properties for repairing bone defects. The scaffolds were evaluated regarding their morphology, porosity, degradation and cellular response. The scaffolds for further investigation were added in a rat calvaria defect model. The study showed that after eight weeks, the bone formation was relatively higher in the collagen/nano-hydroxyapatite/doxycycline group with completely filled defect when compared with other groups. Histopathological evaluation showed that the defect in the collagen/nano-hydroxyapatite/doxycycline group was fully replaced by the new bone and connective tissue. Our results provide evidence supporting the possible applicability of doxycycline-containing scaffolds for successful bone regeneration.

scholarly journals Evidence for Naturally Produced Beauvericins Containing N-Methyl-Tyrosine in Hypocreales Fungi

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 182 ◽  
Author(s):  
Monika Urbaniak ◽  
Łukasz Stępień ◽  
Silvio Uhlig
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Liquid Chromatography ◽  
Oxygen Atom ◽  
Growth Medium ◽  
Structural Isomer ◽  
Liquid Chromatography Mass Spectrometry ◽  
Natural Production ◽  
Additional Oxygen Atom ◽  
Insight Into

Beauvericin is a depsipeptide mycotoxin. The production of several beauvericin analogues has previously been shown among various genera among Hypocreales fungi. This includes so-called beauvenniatins, in which one or more N-methyl-phenylalanine residues is exchanged with other amino acids. In addition, a range of “unnatural” beauvericins has been prepared by a precursor addition to growth medium. Our aim was to get insight into the natural production of beauvericin analogues among different Hypocreales fungi, such as Fusarium and Isaria spp. In addition to beauvericin, we tentatively identified six earlier described analogues in the extracts; these were beauvericin A and/or its structural isomer beauvericin F, beauvericin C, beauvericin J, beauvericin D, and beauvenniatin A. Other analogues contained at least one additional oxygen atom. We show that the additional oxygen atom(s) were due to the presence of one to three N-methyl-tyrosine moieties in the depsipeptide molecules by using different liquid chromatography–mass spectrometry-based approaches. In addition, we also tentatively identified a beauvenniatin that contained N-methyl-leucine, which we named beauvenniatin L. This compound has not been reported before. Our data show that N-methyl-tyrosine containing beauvericins may be among the major naturally produced analogues in certain fungal strains.

scholarly journals The role of connectivity in significant bandgap narrowing for fused-pyrene based non-fullerene acceptors toward high-efficiency organic solar cells

2020 ◽  
Vol 8 (12) ◽  
pp. 5995-6003 ◽  
Author(s):  
Shungang Liu ◽  
Wenyan Su ◽  
Xianshao Zou ◽  
Xiaoyan Du ◽  
Jiamin Cao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Organic Solar Cells ◽  
High Efficiency ◽  
Power Conversion ◽  
Structural Isomer ◽  
Bandgap Narrowing ◽  
Higher Power

Isomers of non-fullerene acceptors with pyrene as cores but fused at different positions were studied. FPIC6 possessed ∼119 nm of red-shift absorption and much higher power conversion efficiency of 11.55% as compared to its structural isomer FPIC5.

Mutagenic activities of a chlorination by-product of butamifos, its structural isomer, and their related compounds

Chemosphere ◽  
2010 ◽  
Vol 78 (4) ◽  
pp. 482-487 ◽  
Author(s):  
Masahiro Kamoshita ◽  
Koji Kosaka ◽  
Osamu Endo ◽  
Mari Asami ◽  
Takako Aizawa
Keyword(s):  
Structural Isomer ◽  
Related Compounds

scholarly journals Biodesulfurization of Naphthothiophene and Benzothiophene through Selective Cleavage of Carbon-Sulfur Bonds by Rhodococcus sp. Strain WU-K2R

2002 ◽  
Vol 68 (8) ◽  
pp. 3867-3872 ◽  
Author(s):  
Kohtaro Kirimura ◽  
Toshiki Furuya ◽  
Rika Sato ◽  
Yoshitaka Ishii ◽  
Kuniki Kino ◽  
...  
Keyword(s):  
Sole Source ◽  
Diesel Oil ◽  
The Other ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Structural Isomer ◽  
Degradation Pathways ◽  
Spectrometry Analysis ◽  
Specific Degradation ◽  
Rhodococcus Sp

ABSTRACT Naphtho[2,1-b]thiophene (NTH) is an asymmetric structural isomer of dibenzothiophene (DBT), and in addition to DBT derivatives, NTH derivatives can also be detected in diesel oil following hydrodesulfurization treatment. Rhodococcus sp. strain WU-K2R was newly isolated from soil for its ability to grow in a medium with NTH as the sole source of sulfur, and growing cells of WU-K2R degraded 0.27 mM NTH within 7 days. WU-K2R could also grow in the medium with NTH sulfone, benzothiophene (BTH), 3-methyl-BTH, or 5-methyl-BTH as the sole source of sulfur but could not utilize DBT, DBT sulfone, or 4,6-dimethyl-DBT. On the other hand, WU-K2R did not utilize NTH or BTH as the sole source of carbon. By gas chromatography-mass spectrometry analysis, desulfurized NTH metabolites were identified as NTH sulfone, 2′-hydroxynaphthylethene, and naphtho[2,1-b]furan. Moreover, since desulfurized BTH metabolites were identified as BTH sulfone, benzo[c][1,2]oxathiin S-oxide, benzo[c][1,2]oxathiin S,S-dioxide, o-hydroxystyrene, 2-(2′-hydroxyphenyl)ethan-1-al, and benzofuran, it was concluded that WU-K2R desulfurized NTH and BTH through the sulfur-specific degradation pathways with the selective cleavage of carbon-sulfur bonds. Therefore, Rhodococcus sp. strain WU-K2R, which could preferentially desulfurize asymmetric heterocyclic sulfur compounds such as NTH and BTH through the sulfur-specific degradation pathways, is a unique desulfurizing biocatalyst showing properties different from those of DBT-desulfurizing bacteria.

scholarly journals Introducing a new category of activity cliffs combining different compound similarity criteria

2020 ◽  
Vol 11 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Huabin Hu ◽  
Jürgen Bajorath
Keyword(s):  
Similarity Criteria ◽  
Structural Isomer ◽  
Molecular Pair ◽  
Similarity Relationships ◽  
Activity Cliffs

Similarity relationships. Shown are matched molecular pair (MMP) and structural isomer relationships, which provide the basis for the introduction of a new category of activity cliffs.

Effect of solvent structural isomer on microstructural evolution in polythiophene film during solidification

2019 ◽  
Vol 71 ◽  
pp. 150-155
Author(s):  
Ja Yun Choi ◽  
Su Jeong Kang ◽  
Hyun Ho Kim ◽  
Yeong Don Park
Keyword(s):  
Microstructural Evolution ◽  
Structural Isomer ◽  
Effect Of Solvent ◽  
Polythiophene Film
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