EFFECT OF OXYGENATED COMPOUNDS ON 1,3-BUTADIENE POLYMERIZATIONS PERFORMED WITH NEODYMIUM VERSATATE. PART I: ALCOHOLS, ALDEHYDES, KETONES, AND WATER

2021 ◽  
Author(s):  
Luciana Dutra ◽  
Mateus Vasconcelos ◽  
Anderson Cazumba ◽  
Maria Clara Scaldaferri ◽  
Márcio Henrique Dos Santos Andrade ◽  
...  
Keyword(s):  
Inhibitory Effects ◽  
Mass Distributions ◽  
Sustainable Technologies ◽  
Oxygenated Compounds ◽  
Crotyl Alcohol ◽  
Low Concentrations ◽  
Acetone Water ◽  
Steam Cracking ◽  
Cracking Process ◽  
First Time

ABSTRACT 1,3-butadiene (1,3-BD) is a building block produced mainly as a byproduct of the ethylene steam cracking process. However, due to the growing interest in sustainable technologies, there is also growing interest in manufacturing 1,3-BD from ethanol. For this reason, taking into account that the ethanol-derived 1,3-BD can contain oxygenated contaminants that are difficult to remove, the present manuscript investigates for the first time how the presence of low concentrations of some oxygenates (acetaldehyde, crotonaldehyde, 3-hydroxybutyraldehyde, acetone, water, ethanol, 1,3-butanodiol, 3-buten2-ol, crotyl alcohol, and 1-butanol) in the 1,3-BD monomer can affect polymerization reactions performed with the neodymium versatate catalyst and modify the characteristics of the obtained polybutadiene products. It is shown that the presence of oxygenated compounds can cause inhibitory effects on the course of the polymerization and modify the molar mass distributions and flow properties of the final products, although all analyzed samples presented the characteristic high-cis character of polybutadienes produced with the neodymium versatate catalyst.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

scholarly journals A novel role for WAVE1 in controlling actin network growth rate and architecture

2015 ◽  
Vol 26 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Meredith O. Sweeney ◽  
Agnieszka Collins ◽  
Shae B. Padrick ◽  
Bruce L. Goode
Keyword(s):  
Actin Filament ◽  
Specific Activity ◽  
Inhibitory Effect ◽  
Actin Network ◽  
Inhibitory Effects ◽  
Cellular Functions ◽  
Network Growth ◽  
Assembly Kinetics ◽  
Filament Networks ◽  
First Time

Branched actin filament networks in cells are assembled through the combined activities of Arp2/3 complex and different WASP/WAVE proteins. Here we used TIRF and electron microscopy to directly compare for the first time the assembly kinetics and architectures of actin filament networks produced by Arp2/3 complex and dimerized VCA regions of WAVE1, WAVE2, or N-WASP. WAVE1 produced strikingly different networks from WAVE2 or N-WASP, which comprised unexpectedly short filaments. Further analysis showed that the WAVE1-specific activity stemmed from an inhibitory effect on filament elongation both in the presence and absence of Arp2/3 complex, which was observed even at low stoichiometries of WAVE1 to actin monomers, precluding an effect from monomer sequestration. Using a series of VCA chimeras, we mapped the elongation inhibitory effects of WAVE1 to its WH2 (“V”) domain. Further, mutating a single conserved lysine residue potently disrupted WAVE1's inhibitory effects. Taken together, our results show that WAVE1 has unique activities independent of Arp2/3 complex that can govern both the growth rates and architectures of actin filament networks. Such activities may underlie previously observed differences between the cellular functions of WAVE1 and WAVE2.

Extractives in Betula celtiberica stemwood and isolation and identification of diarylheptanoids in the hydrophilic extract

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Annika I. Smeds ◽  
René Herrera ◽  
Jani Rahkila ◽  
Stefan M. Willför
Keyword(s):  
Biological Effects ◽  
White Birch ◽  
Exact Mass ◽  
Isolation And Identification ◽  
Low Concentrations ◽  
Acetone Water ◽  
Hydrophilic Extract ◽  
Dry Wood ◽  
Interesting Compound ◽  
Flame Ionisation

Abstract In Betula celtiberica (Iberian white birch) stemwood, the content and composition of lipophilic and hydrophilic extractives were determined; these have not been reported previously in this species. The total gravimetric amount of extractives was 2.2% of dry wood, of which lipophilic extractives accounted for 0.39% and hydrophilic extractives 1.84% (determined by gas chromatography–flame ionisation detection [GC–FID]). The lipophilic extract contained mainly triterpenoids and steroids. The hydrophilic extract (acetone–water 95:5 v v−1) contained mainly sugars, compounds not eluting on GC, and a large number of unidentified compounds, which accounted for 0.87% of dry wood and dominated the extract. The compounds were isolated from the extract by silica column chromatography and further purified. GC–electron impact (EI)-MS of the silylated compounds showed characteristic mass fragments that suggested them to be diarylheptanoids (DAHs). This is an interesting compound group, as many of them have shown a large variety of beneficial biological effects. Of over 80 detected DAHs, the exact mass of 17 compounds was determined by electrospray ionisation-quadrupole-time-of-flight (ESI-QTOF)-MS, and of these, the structure of 11 compounds was elucidated by nuclear magnetic resonance (NMR). One was a meta,para-bridged diphenylether and 10 were meta,meta-bridged biphenyls, of which one, 3,8,9,17-tetrahydroxy-[7,0]-metacyclophane, has not been described previously. Because of low concentrations, 21 DAHs were only tentatively identified, and of these, as many as 17 seem to be previously undescribed compounds.

Morin Exerts Anti-Diabetic Effects in Human HepG2 Cells Via Down-Regulation of miR-29a

2018 ◽  
Vol 127 (09) ◽  
pp. 615-622 ◽  
Author(s):  
Toktam Razavi ◽  
Shideh Montasser Kouhsari ◽  
Khalil Abnous
Keyword(s):  
Insulin Signaling ◽  
High Glucose ◽  
Hepg2 Cells ◽  
Target Genes ◽  
Expression Level ◽  
Inhibitory Effects ◽  
Down Regulation ◽  
Insulin Mimetic ◽  
Important Regulator ◽  
First Time

Abstract Diabetes mellitus is a complex metabolic disease around the world that is characterized by hyperglycemia resulting from impaired insulin secretion, insulin action, or both. MicroRNA-29a is an important regulator of insulin signaling and gluconeogenesis pathways through IRS2, PI3K and PEPCK expressions which up regulates in Diabetes. Morin is a substantial bioflavonoid which has insulin mimetic effect, and interacting with nucleic acids and proteins. In this study HepG2 cells, were exposed to high glucose to induce diabetic condition. We have determined whether high glucose stimulation might promotes miR-29a expression level in HepG2 cells and subsequently evaluated the Morin treatment effects on this state. In HepG2 cells, high glucose increases miR-29a expression level and decreases its target genes, IRS2 and PI3K expression, and increases associated downstream gene in gluconeogenic pathway, PEPCK. Morin treatment down regulates miR-29a expression level and improves insulin signaling and glucose metabolism. To confirm the inhibitory effects of Morin on miR-29a, we have transfected cells with mimic and inhibitor-miR-29a. This study for the first time identifies that Morin improves diabetic condition through down regulation of the miR-29a level, and suggest that this new inhibitor of miR-29a may be a useful biomedicine to treat diabetes.

scholarly journals Measuring Thiols in Single Cultivar South African Red Wines Using 4,4-Dithiodipyridine (DTDP) Derivatization and Ultraperformance Convergence Chromatography-Tandem Mass Spectrometry

Foods ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 138 ◽  
Author(s):  
Mpho Mafata ◽  
Maria Stander ◽  
Baptiste Thomachot ◽  
Astrid Buica
Keyword(s):  
South African ◽  
Red Wine ◽  
High Sensitivity ◽  
White Wine ◽  
Wine Aroma ◽  
Low Concentrations ◽  
Varietal Thiols ◽  
Cultivar Differentiation ◽  
First Time ◽  
Ionization Methods

Wine varietal thiols are important contributors to wine aroma. The chemical nature of thiols makes them difficult to measure due to low concentrations, high sensitivity to oxidation, and low ionization. Methods for the measurement of thiols usually consist of multiple steps of sample preparation followed by instrumental measurement. Studies have collected large datasets of thiols in white wine but not in red wine, due to the lack of availability of suitable methods. In this study, for the first time, convergence chromatography was used to measure thiols in red wine at ultratrace levels with improved sensitivity compared to previous methods. Performance parameters (selectivity, linearity, limits of detection, precision, accuracy) were tested to demonstrate the suitability of the method for the proposed application. Red wine thiols were measured in South African Pinotage, Shiraz, and Cabernet Sauvignon wines (n = 16 each). Cultivar differentiation using the thiol profile was demonstrated.

Autotoxic compounds from rhizosphere soil of lanzhou lily extracts: Identification and biological activity

2021 ◽  
Vol 53 (1) ◽  
pp. 111-126
Author(s):  
Y. F. Huang ◽  
E. H. Zhang ◽  
X. H. Zhang ◽  
Q. Wang ◽  
H. Z. Wang ◽  
...  
Keyword(s):  
Antioxidant Enzyme ◽  
Seedling Growth ◽  
Rhizosphere Soil ◽  
Gas Chromatography Mass Spectrometry ◽  
Antioxidant Enzyme Activities ◽  
Photosynthetic Parameters ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
High Concentrations ◽  
Lanzhou Lily

We investigated the autotoxicity of Lanzhou lily rhizosphere soil with different cultivation years. The allelochemicals in such soils were isolated and identified by gas chromatography-mass spectrometry (GC-MS). Based on our earlier studies, the antioxidant 2246 and dioctyl terephthalate were found in lily sick soil were used in pot experiments determine to their autotoxic effects on the Lanzhou lily seedlings growth, photosynthetic parameters and antioxidant enzyme activities in seedling leaves. The content of antioxidant 2246 and dioctyl terephthalate was determined by GC-MS in rhizosphere soil of different cultivation years. The aqueous extracts of Lanzhou lily rhizosphere soil promoted the growth of its own seedlings at 0.2 mg·mL-1, however, the concentrations > 2 mg·mL-1 were inhibitory. The longer the cultivation period (1-yr, 2-yr and 4-yr), the stronger were the inhibitory effects. In rhizosphere soils of 1-yr, 2-yr and 4-yr ; 8,: 15 and 18 compounds were identified, respectively. The identified compounds were camphor, 3-hydroxy-4-methoxy-benzaldehyde, 2,4-bis(1,1- dimethylethyl)-phenol, tributyl phosphate, dibutyl phthalate, antioxidant 2246 and dioctyl terephthalater and these are reported as allelochemicals. The pot experiment results showed that low concentrations of antioxidant 2246 stimulated the seedling growth but high concentrations were inhibitory, while all concentrations of dioctyl terephthalater inhibited the seedling growth. At 100 mg·mL-1, the antioxidant 2246 and dioctyl terephthalate significantly inhibited the photosynthesis and antioxidant enzyme activity in leaves (P <0.05). Furthermore, the content of these two compounds in soils increased with the increase of cultivation years. These results suggested that allelochemicals accumulated in replanted soil contributed to the autotoxicity of Lanzhou lily in rhizosphere soil.

scholarly journals Natural Clovanes from the Gorgonian Coral Rumphella Antipathies

2013 ◽  
Vol 8 (8) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Hsu-Ming Chung ◽  
Wei-Hsien Wang ◽  
Tsong-Long Hwang ◽  
Yang-Chang Wu ◽  
Ping-Jyun Sung
Keyword(s):  
Spectral Data ◽  
Natural Source ◽  
Human Neutrophils ◽  
Spectroscopic Methods ◽  
Superoxide Anions ◽  
Inhibitory Effects ◽  
Gorgonian Coral ◽  
First Time

Three natural clovane-related sesquiterpenoids, 2β-acetoxyclovan-9α-ol (1), 9α-acetoxyclovan-2β-ol (2) and clovan-2β,9β-diol (3), were isolated from the gorgonian coral Rumphella antipathies. The structures of clovanes 1–3 were elucidated by spectroscopic methods and by comparison of the spectral data with those of known clovane analogues. This is the first time that clovanes 1–3 have been isolated from a natural source. Clovanes 1 and 2 displayed inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils.

Mode of Action of the Hypertrehalosaemic Peptides from the American Cockroach

1985 ◽  
Vol 40 (9-10) ◽  
pp. 670-676 ◽  
Author(s):  
Gerd Gäde
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mode Of Action ◽  
Glycogen Phosphorylase ◽  
Fat Body ◽  
American Cockroach ◽  
Dependent Manner ◽  
Low Concentrations ◽  
First Time ◽  
Dose Dependent

Abstract Although crude extracts of cockroach (Periplaneta amencana) corpora cardiaca have been shown previously to affect the activity of adenylate cyclase and phosphorylase, we demonstrate in the present study for the first time that low concentrations (0.5 to 5 pmol) of the synthetic myoactive peptides. M I and M II, also affect these systems; these myoactive peptides are identical to the hypertrehalosaemic hormones I and II, and cause an increase in the concentration of the second messenger cyclic AMP in the fat body.In addition, both octapeptides activate fat body glycogen phosphorylase and promote breakdown of fat body glycogen. Both peptides increase the levels to haemolymph carbohydrate in a dose-dependent manner.

Sign in / Sign up

Export Citation Format

Share Document