Synthesis of Novel Chiral Calix[4]crown: Lariat Calix[4]-1,3-aza-crown with Chiral Amino Acid Group as Branched Chain

2011 ◽  
Vol 8 (5) ◽  
pp. 358-360
Author(s):  
Fafu Yang ◽  
Biqiong Hong ◽  
Hongyu Guo ◽  
Zhisheng Huang ◽  
Xiaoyi Zhang
Keyword(s):  
Amino Acid ◽  
Acid Group ◽  
Amino Acid Group ◽  
Branched Chain

Stability Constants of Some Metal Complexes Formed by Mimosine and Related Compounds

1979 ◽  
Vol 32 (1) ◽  
pp. 21 ◽  
Author(s):  
H Stunzi ◽  
DD Perrin ◽  
T Teitei ◽  
RLN Harris
Keyword(s):  
Amino Acid ◽  
Stability Constants ◽  
Metal Binding ◽  
Acid Group ◽  
Biologically Active ◽  
Amino Acid Group ◽  
Dimeric Complexes ◽  
Major Species ◽  
Active Amino Acid ◽  
Related Compounds

Complex formation of the biologically active amino acid L-mimosine [α-amino-β-(3-hydroxy-4-oxo-1,4-dihydropyridin-1-yl)propanoic acid (1)], mimosinic acid (2), mimosine methyl ether (9) and 3-hydroxy-1-methylpyridin-4(1H)-one (4) with Cu2+, Zn2+, Cd2+ and Pb2+ was studied. Stability constants were determined by potentiometric titration in 0.15M KNOB3 as inert electrolyte at 37�. In the monomeric complexes formed by the mimosine derivatives, metal binding by the hydroxypyridone moiety was favoured relative to the amino acid group. With mimosine, dimeric complexes were major species. Under physiological conditions, mimosine binds copper and zinc ions more strongly than do simpler amino acids.

scholarly journals Reversible Oxygenation ofα-Amino Acid–Cobalt(II) Complexes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xincun Zhang ◽  
Fan Yue ◽  
Hui Li ◽  
Yan Huang ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Time Lapse ◽  
Acid Group ◽  
Oxygen Electrode ◽  
Oxygen Carriers ◽  
Amino Acid Group ◽  
Specific Configuration ◽  
Reversible Formation ◽  
Hydroxy Groups ◽  
The Relationship

We systematically investigated the reversibility, time lapse, and oxygenation-deoxygenation properties of 15 naturalα-amino acid–Co(II) complexes through UV-vis spectrophotometer, polarographic oxygen electrode, and DFT calculations, respectively, to explore the relationship between the coordinating structure and reversible oxygenation ofα-amino acid–Co(II) complexes. Results revealed that theα-amino acid structure plays a key role in the reversible oxygenation properties of these complexes. The specific configuration of theα-amino acid group affects theeg1electron of Co(II) transfer to theπ⁎orbit of O2; this phenomenon also favors the reversible formation and dissociation of Co–O2bond when O2coordinates with Co(II) complexes. Therefore, the co-coordination of amino and carboxyl groups is a determinant of Co complexes to absorb O2reversibly. The group adjacent to theα-amino acid unit evidently influences the dioxygen affinity and antioxidation ability of the complexes. The presence of amino (or imino) and hydroxy groups adjacent to theα-amino acid group increases the oxygenation-deoxygenation rate and the number of reversible cycles. Our findings demonstrate a new mechanism to develop reversible oxygenation complexes and to reveal the oxygenation of oxygen carriers.

scholarly journals Low-arginine and low-protein diets induce hepatic lipid accumulation through different mechanisms in growing rats

2020 ◽  
Author(s):  
Lila Otani ◽  
Hiroki Nishi ◽  
Ayaka Koyama ◽  
Yuta Akasaka ◽  
Yusuke Taguchi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fatty Liver ◽  
Insulin Signaling ◽  
Acid Group ◽  
De Novo Lipogenesis ◽  
Total Amino Acid ◽  
Amino Acid Group ◽  
Acid Diet ◽  
Low Protein ◽  
Amino Acid Diet

Abstract Background Dietary protein deficiency and amino acid uimbalance cause hepatic fat accumulation. We previously demonstrated that only arginine deficiency as well as total amino acid deficiency in a diet caused significant hepatic triglyceride (TG) accumulation in young Wistar rats. In this study, we explored the mechanisms of this fatty liver formation using these two models. Methods A low-total-amino acid diet (equivalent to 5% protein) and a low-arginine diet (solely the arginine content alone is as low as the low-total-amino acid diet) to the rats for 2 weeks. Results There was substantially greater hepatic TG accumulation in the low-arginine group than in the low-total-amino acid group. The low-total-amino-acid diet potentiated insulin signals in the liver and enhanced de novo lipogenesis. By contrast, the low-arginine diet inhibited hepatic very-low-density lipoprotein secretion, without affecting hepatic insulin signaling and lipogenesis. Conclusions We conclude that, although the arginine intake of the low-arginine group was as low as that of the low-total-amino-acid group, these two diets developed a fatty liver via completely different mechanisms. The potentiation of insulin signaling and resultant increases in fatty acid synthesis seem to drive the effects of a low-protein diet, whereas lower VLDL secretion may be the main causes of low-arginine diet-induced TG accumulation in the liver.

A significant pool of amino acids is adsorbed on blood cell membranes

1991 ◽  
Vol 11 (4) ◽  
pp. 223-230 ◽  
Author(s):  
C. Picó ◽  
A. Pons ◽  
A. Palou
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Blood Cell ◽  
Whole Blood ◽  
Wistar Rats ◽  
Cell Membranes ◽  
Acid Group ◽  
High Adsorption ◽  
Polar Amino Acid ◽  
Amino Acid Group

It is well known that the amino acids in the blood are distributed between the plasma and inside the cells. This study was conducted to determine whether amino acids can be located adsorbed on blood cell membranes. The amino acid concentration in the deproteinized haemolysed blood was higher than that in the fraction of blood after removal of the blood cell membranes by centrifugation. These results showed that a pool of amino acids representing 21.1% of the whole blood cell amino acids was adsorbed on the blood cell membranes of adult Wistar rats. The non-polar amino acids showed high adsorption on the membrane, whereas out of the polar amino acid group, only the non-ionic amino acids did adsorb.

scholarly journals A comparative study of intravenous hydration and amnioinfusion for IUGR associated with oligohydramnios in pregnant women and fetomaternal outcome

2021 ◽  
Vol 10 (3) ◽  
pp. 955
Author(s):  
Garima Kumari
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
Pregnant Women ◽  
Acid Group ◽  
P Value ◽  
Delivery Mode ◽  
Significant Implication ◽  
Amino Acid Group ◽  
Infusion Group ◽  
Intravenous Hydration

Background: Ultrasound assessment of amniotic fluid has significant implication in obstetric care and it has become an integral and important component of pregnancy assessment.Methods: A prospective study done in all pregnant women (n=30) who had been diagnosed with oligohydromnios (with AFI<8 by Phelan’s method) by ultrasonography will be attending in obstetric gynecology department SMS Medical College, Jaipur will be selected according to inclusion or exclusion criteria (as per sample size) after written informed consent.Results: Higher incidence of preterm delivery in the i.v. infusion group as compared to the amino acid group and difference was significant (p value <0.05). In amnioinfusion group 3 cases (20.0%) had LSCS and in i.v. infusion group 6 cases (40.0%) had delivered by LSCS. The distribution of delivery mode did not differ significantly across two intervention groups (p value >0.05). Significantly higher proportion of cases from amino acid group had larger birth weight and significantly higher proportion of cases from i.v. infusion group had smaller birth weight (p value <0.001).Conclusions: This study points towards the use of intravenous hydration and amnioinfusion in increasing the liquor in oligohydramnios associated with IUGR and proves useful in reducing perinatal morbidity and mortality.

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