Synthesis of Analogues of GABA. II. 4-Alkyl-4-aminobut-2-enoic Acids and a New Synthesis of Some Vinyl α-Amino Acids

1979 ◽  
Vol 32 (11) ◽  
pp. 2507 ◽  
Author(s):  
RD Allan
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Gaba Uptake ◽  
Synthetic Route ◽  
Conformationally Restricted ◽  
Enzyme Systems ◽  
New Synthesis ◽  
Methylene Groups ◽  
By Products

A series of 4-alkyl-4-aminobut-2-enoic acids (2)-(5) has been prepared as conformationally restricted analogues of GABA. The synthetic route which involved allylic bromination followed by displacement with ammonia also gave vinyl glycine analogues (7)-(9) as readily purified by-products of the reaction. The low biological activity in vitro against GABA uptake, binding and enzyme systems of (E)-2-aminocyclohexylideneacetic acid (4) and (E)-2-aminocyclopentylideneacetic acid (5) has been interpreted in terms of steric hindrance by the ring-forming methylene groups at the particularactive sites concerned.

scholarly journals Translational and Structural Requirements of the Early Nodulin Gene enod40, a Short-Open Reading Frame-Containing RNA, for Elicitation of a Cell-Specific Growth Response in the Alfalfa Root Cortex

2001 ◽  
Vol 21 (1) ◽  
pp. 354-366 ◽  
Author(s):  
Carolina Sousa ◽  
Christina Johansson ◽  
Celine Charon ◽  
Hamid Manyani ◽  
Christof Sautter ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Rna Structure ◽  
Open Reading Frames ◽  
In Vitro Translation ◽  
Cortical Cells ◽  
Root Cortex ◽  
Reading Frame ◽  
Early Nodulin

ABSTRACT A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin geneenod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5′ and 3′ regions ofenod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNAs.

scholarly journals Production and Physicochemical Characterization of Gelatin and Collagen Hydrolysates from Turbot Skin Waste Generated by Aquaculture Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 491
Author(s):  
Jesus Valcarcel ◽  
Javier Fraguas ◽  
Carolina Hermida-Merino ◽  
Daniel Hermida-Merino ◽  
Manuel M. Piñeiro ◽  
...  
Keyword(s):  
Amino Acids ◽  
Structural Integrity ◽  
Physicochemical Characterization ◽  
Essential Amino Acids ◽  
Storage And Loss Moduli ◽  
Food And Feed ◽  
Collagen Hydrolysates ◽  
First Time ◽  
By Products

Rising trends in fish filleting are increasing the amount of processing by-products, such as skins of turbot, a flatfish of high commercial value. In line with circular economy principles, we propose the valorization of turbot skins through a two-step process: initial gelatin extraction described for the first time in turbot, followed by hydrolysis of the remaining solids to produce collagen hydrolysates. We assayed several methods for gelatin extraction, finding differences in gelatin properties depending on chemical treatment and temperature. Of all methods, the application of NaOH, sulfuric, and citric acids at 22 °C results in the highest gel strength (177 g), storage and loss moduli, and gel stability. We found no relation between mechanical properties and content of pyrrolidine amino acids, but the best performing gelatin displays higher structural integrity, with less than 30% of the material below 100 kDa. Collagen hydrolysis was more efficient with papain than alcalase, leading to a greater reduction in Mw of the hydrolysates, which contain a higher proportion of essential amino acids than gelatin and show high in vitro anti-hypertensive activity. These results highlight the suitability of turbot skin by-products as a source of gelatin and the potential of collagen hydrolysates as a functional food and feed ingredient.

The Presence of Novel Amino Acids in the Cytoplasmic Domain of Stem Cell Factor Results in Hematopoietic Defects inSteel17H Mice

Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1915-1925 ◽  
Author(s):  
Reuben Kapur ◽  
Ryan Cooper ◽  
Xingli Xiao ◽  
Mitchell J. Weiss ◽  
Peter Donovan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bone Marrow ◽  
Biological Activity ◽  
Stem Cell ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Stem Cell Factor ◽  
Cytoplasmic Domain

Abstract Stem cell factor (SCF) is expressed as an integral membrane growth factor that may be differentially processed to produce predominantly soluble (S) (SCF248) or membrane-associated (MA) (SCF220) protein. A critical role for membrane presentation of SCF in the hematopoietic microenvironment (HM) has been suggested from the phenotype of the Steel-dickie(Sld) mice, which lack MA SCF, and by studies performed in our laboratory (and by others) using long-term bone marrow cultures and transgenic mice expressing different SCF isoforms.Steel17H (Sl17H) is an SCF mutant that demonstrates melanocyte defects and sterility in males but not in females. The Sl17H allele contains a intronic mutation resulting in the substitution of 36 amino acids (aa’s) in the SCF cytoplasmic domain with 28 novel aa’s. This mutation, which affects virtually the entire cytoplasmic domain of SCF, could be expected to alter membrane SCF presentation. To investigate this possibility, we examined the biochemical and biologic properties of the Sl17H-encoded protein and its impact in vivo and in vitro on hematopoiesis and on c-Kit signaling. We demonstrate that compound heterozygous Sl/Sl17H mice manifest multiple hematopoietic abnormalities in vivo, including red blood cell deficiency, bone marrow hypoplasia, and defective thymopoiesis. In vitro, both S and MA Sl17H isoforms of SCF exhibit reduced cell surface expression on stromal cells and diminished biological activity in comparison to wild-type (wt) SCF isoforms. These alterations in presentation and biological activity are associated with a significant reduction in the proliferation of an SCF-responsive erythroid progenitor cell line and in the activation of phosphatidylinositol 3-Kinase/Akt and mitogen-activated protein-Kinase signaling pathways. In vivo, transgene expression of the membrane-restricted (MR) (SCFX9/D3) SCF in Sl/Sl17H mutants results in a significant improvement in peripheral red blood cell counts in comparison toSl/Sl17H mice.

Phosphoramidate Derivatives of AZT as Inhibitors of HIV: Studies on the Carboxyl Terminus

1993 ◽  
Vol 4 (2) ◽  
pp. 97-101 ◽  
Author(s):  
C. McGuigan ◽  
R. N. Pathirana ◽  
S. S.-M. Choi ◽  
D. Kinchington ◽  
T. J. O'Connor
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Carboxyl Terminus ◽  
Amino Ester ◽  
Carboxy Terminus ◽  
Free Nucleotides ◽  
Derivatives Of ◽  
Anti Hiv ◽  
Ester Lead

Novel phosphoramidate derivatives of the anti-HIV nucleoside analogue AZT have been prepared by phosphorochloridate chemistry. These materials carry carboxy-protected, amino acids, and are designed to act as membrane-soluble prodrugs of the bio-active free nucleotides. In vitro evaluation revealed the compounds to have a pronounced, selective antiviral activity. In particular, variation in the carboxy terminus region is studied. For alkyl phosphates small changes in the structure of the amino ester lead to marked changes in biological activity. However, for analogous aryl phosphates there is little dependence on the structure of the ester. This suggests a different mechanism of action for these two categories of phosphate prodrug.

scholarly journals Effect of the Plastein Reaction in Presence of Extrinsic Amino Acids on the Protective Activity of Casein Hydrolysate against Ethanol-Induced Damage in HHL-5 Cells

Foods ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 112
Author(s):  
Li-Ying Bo ◽  
Jia-Nan Pang ◽  
Chun-Li Song ◽  
Tie-Jing Li
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Treatment Time ◽  
Biological Activities ◽  
Casein Hydrolysate ◽  
Protective Activity ◽  
Potential Health ◽  
Plastein Reaction ◽  
Casein Hydrolysates

Casein hydrolysates (CH) were prepared using papain and modified by the plastein reaction (CH-P) in the presence of extrinsic phenylalanine (CH-P-Phe) or tryptophan (CH-P-Trp). The in vitro protective activity of CH and its modified products against ethanol-induced damage in HHL-5 cells was investigated. The results showed that the modification by the plastein reaction reduced the amino group content of CH. However, the modification by the plastein reaction in the presence of extrinsic amino acids could enhance the antioxidant, proliferative, cell cycle arresting, and anti-apoptosis activity of CH. Biological activities of CH and its modified products in the HHL-5 cells varied depending on the hydrolysate concentration (1, 2, and 3 mg/mL) and treatment time (24, 48, and 72 h). Generally, higher biological activities were found after cell treatment with CH or its modified products at concentration of 2 mg/mL for 48 h compared to other treatments. In addition, CH modified in the presence of tryptophan (CH-P-Trp) showed higher biological activity than that modified in the presence of phenylalanine (CH-P-Phe). Based on the obtained results, it can be concluded that casein hydrolysates with enhanced biological activity and potential health benefits can be produced by papain and the plastein reaction with the incorporation of extrinsic amino acids.

The Presence of Novel Amino Acids in the Cytoplasmic Domain of Stem Cell Factor Results in Hematopoietic Defects inSteel17H Mice

Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1915-1925 ◽  
Author(s):  
Reuben Kapur ◽  
Ryan Cooper ◽  
Xingli Xiao ◽  
Mitchell J. Weiss ◽  
Peter Donovan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bone Marrow ◽  
Biological Activity ◽  
Stem Cell ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Stem Cell Factor ◽  
Cytoplasmic Domain

Stem cell factor (SCF) is expressed as an integral membrane growth factor that may be differentially processed to produce predominantly soluble (S) (SCF248) or membrane-associated (MA) (SCF220) protein. A critical role for membrane presentation of SCF in the hematopoietic microenvironment (HM) has been suggested from the phenotype of the Steel-dickie(Sld) mice, which lack MA SCF, and by studies performed in our laboratory (and by others) using long-term bone marrow cultures and transgenic mice expressing different SCF isoforms.Steel17H (Sl17H) is an SCF mutant that demonstrates melanocyte defects and sterility in males but not in females. The Sl17H allele contains a intronic mutation resulting in the substitution of 36 amino acids (aa’s) in the SCF cytoplasmic domain with 28 novel aa’s. This mutation, which affects virtually the entire cytoplasmic domain of SCF, could be expected to alter membrane SCF presentation. To investigate this possibility, we examined the biochemical and biologic properties of the Sl17H-encoded protein and its impact in vivo and in vitro on hematopoiesis and on c-Kit signaling. We demonstrate that compound heterozygous Sl/Sl17H mice manifest multiple hematopoietic abnormalities in vivo, including red blood cell deficiency, bone marrow hypoplasia, and defective thymopoiesis. In vitro, both S and MA Sl17H isoforms of SCF exhibit reduced cell surface expression on stromal cells and diminished biological activity in comparison to wild-type (wt) SCF isoforms. These alterations in presentation and biological activity are associated with a significant reduction in the proliferation of an SCF-responsive erythroid progenitor cell line and in the activation of phosphatidylinositol 3-Kinase/Akt and mitogen-activated protein-Kinase signaling pathways. In vivo, transgene expression of the membrane-restricted (MR) (SCFX9/D3) SCF in Sl/Sl17H mutants results in a significant improvement in peripheral red blood cell counts in comparison toSl/Sl17H mice.

Synthesis, in vitro biological activity, hydrolytic stability and docking of new analogs of BIM-23052 containing halogenated amino acids

Amino Acids ◽  
2020 ◽  
Vol 52 (11-12) ◽  
pp. 1581-1592
Author(s):  
Dancho Danalev ◽  
Desislava Borisova ◽  
Spaska Yaneva ◽  
Maya Georgieva ◽  
Anelia Balacheva ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Hydrolytic Stability

Process Optimization and Composition Analysis of Antioxidant Enzymatic Hydrolysate from Squid By-Products by Papain

2011 ◽  
Vol 79 ◽  
pp. 198-203 ◽  
Author(s):  
Bin Wang ◽  
Jia Hui Ma ◽  
You Le Qu ◽  
Xian Wang ◽  
Li Li
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Hydrolysate ◽  
Essential Amino Acids ◽  
Single Factor ◽  
Scavenging Ratio ◽  
Dpph Scavenging ◽  
By Products ◽  
Total Amino Acids

In order to evaluate the high-value application of squid by-products yielded hydrolysate, the process of preparation and purification technology, chemical composition and in vitro antioxidant activity of the hydrolysate were investigated. The optimal conditions of papain hydrolysis were obtained by single-factor experiments and orthogonal test with the DPPH• scavenging ratio as index, amino acid composition was analysed by automatic amino acid analyzer, the hydrolysate was isolated with a Sephadex G-25 column. Based on single-factor experiments, the hydrolysate with the DPPH• scavenging ratio being 53.96 % was gained under the optimal condition of enzymolysis temperature of 45 °C, enzymolysis time of 3 h, total enzyme dose of 1.2 %, and the pH value of 7. The protein content of the hydrolysate reached up to 17.53 %, and the essential amino acids were accounted for 51.06 % of total amino acids. The largest content amino acid was glutamic acid, which accounted for 10.74 % of total amino acids. Compared with the amino acid profiles recommended by FAO/WHO, the quality of the protein hydrolysate was high, as it was rich in essential amino acids, including isoleucine, leucine, lysine, methionine and cystine, threonine, tryptophan, and valine, which covered 88 %-100 % of the FAO/WHO recommended. The hydrolysate was divided into three fractions (F1-F3) using a Sephadex G-25 column, the F1 possessed the highest antioxidation activity with the reducing power, •OH and DPPH• scavenging ratio being 0.236, 18.13 % and 63.85 % at the concentration of 5 mg/mL. Compared with the retention time of the reduced glutathione chromatomap, the relative molecular mass of F1 was higher than 307, F2 and F3 was lower than 307. The result revealed that the protein hydrolysate from squid by-products by papain had strongly antioxidant capacity in vitro and high nutrition, and this finding provided a new way of advanced exploitation of squid scrap resources.

Synthesis, in vitro biological activity and docking of new analogs of BIM-23052 containing unnatural amino acids

Amino Acids ◽  
2019 ◽  
Vol 51 (9) ◽  
pp. 1247-1257 ◽  
Author(s):  
Emilia Naydenova ◽  
Diana Wesselinova ◽  
Svetlana Staykova ◽  
Dancho Danalev ◽  
Tatyana Dzimbova
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Unnatural Amino Acids

scholarly journals Effect of Acacia purified tannins extract and polyethylene glycol treatment on in vitro ruminal fermentation pattern and methane production

2020 ◽  
pp. 50-62
Author(s):  
Khaoula Khelalfa ◽  
Rabah Arhab ◽  
Antonio Ignacio Martín-García ◽  
Nabila Zaabat ◽  
Alejandro Belanche
Keyword(s):  
Biological Activity ◽  
Polyethylene Glycol ◽  
Methane Production ◽  
Condensed Tannins ◽  
Volatile Fatty Acids ◽  
Neutral Detergent Fiber ◽  
Barley Straw ◽  
Fermentation Parameters ◽  
By Products

Condensed tannins are polyphenolic compounds which can exert beneficial effects in ruminants. They have the ability to bind proteins and decrease their degradation. They have also been reported to reduce methanogenesis and improve ruminants performances. The present work aimed to study the effect of purified condensed tannins from Acacia horrida extract on fermentation parameters, gas and methane production. In this context, seven substrates were selected: four Acacia species (Acacia pycnantha, Acacia dealbata, Acacia horrida and Acacia cyanophylla) and three plant by-products (date palm leaves, grenade peel and artichoke stems). Biological activity of tannins was evaluated by the incubation of the substrates in vitro with Polyethylene glycol (PEG). Tannins decreased concentration of all fermentation parameters (gas (p < 0.0001), methane (CH4) (p= 0.0983), ammonia (N-NH3) (p= 0.0382), Volatile Fatty Acids (VFA) (p= 0.0009), acetate (p <0.0001), propionate (p= 0.1024), butyrate (p= 0.0373), isobutyrate (p= 0.0046), valerate (p < 0.0001), isovalerate (p= 0.0032)). Substrates were also characterized by their content in main nutrients (dry matter (DM), organic matter (OM), ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) ,acid detergent lignin (ADL)) and in secondary metabolites (total phenols (TP), total tannins (TT) and condensed tannins (CT) ). All substrates presented high CP content except by-products (> 100 g/kg DM) and moderate cell-wall components. CT content was comprised between 120.5 and 680.4 g/kg DM in plants and between 23.1 and 170.4 g/kg DM in plant by-products. A. horrida presented the highest biological activity. Thus, their CT were extracted and purified on a sephadex LH-20 column. Purified tannins from A. horrida were incubated with two different forages alfalfa hay and barley straw at three different concentrations: 50, 100, 150 mg/g DM. Results showed that purified tannins from A. horrida had no effect on fermentation parameters (P > 0.05). The effects of A. horrida tannins may be strongly linked to their structure and their molecular weight more than to their concentration. For this reason, it is interesting that this work may be completed by physical characterization of these tannins.

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