scholarly journals Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

2019 ◽  
Vol 15 ◽  
pp. 299-309
Author(s):  
Hidekazu Komatsu ◽  
Takashi Shirakawa ◽  
Takeo Uchiyama ◽  
Tsutomu Hoshino
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Structure ◽  
2D Nmr ◽  
Summer Season ◽  
Enoic Acid ◽  
Pseudomonas Cichorii ◽  
Structure Activity ◽  
Detailed Evaluation ◽  
Ester Linkage

Pseudomonas cichorii, which causes varnish spots on lettuce and seriously damages lettuce production during the summer season in the highland areas of Japan (e.g., Nagano and Iwate prefectures) was isolated. The structure of a toxin produced by this organism was analyzed based on the detailed evaluation of its 2D NMR and FABMS spectra, and this compound has not been reported previously. We propose the name cichorinotoxin for this toxin. In conjunction with the D or L configurations of each amino acid, which were determined by Marfey’s method, we propose the structure of cichorinotoxin to be as follows: 3-hydroxydecanoyl-(Z)-dhThr1-D-Pro2-D-Ala3-D-Ala4-D-Ala5-D-Val6-D-Ala7-(Z)-dhThr8-Ala9-Val10-D-Ile11-Ser12-Ala13-Val14-Ala15-Val16-(Z)-dhThr17-D-alloThr18-Ala19-L-Dab20-Ser21-Val22, and an ester linkage is present between D-alloThr18 and Val22 (dhThr: 2-aminobut-2-enoic acid; Dab: 2,4-diaminobutanoic acid). Thus, the toxin is a lipodepsipeptide with 22 amino acids. The mono- and tetraacetate derivatives and two alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce.

scholarly journals α-Amino acid-derived 2-phenylimidazoles with potential antimycobacterial activity

2012 ◽  
Vol 10 (5) ◽  
pp. 1681-1687 ◽  
Author(s):  
Daniel Cvejn ◽  
Věra Klimešová ◽  
Filip Bureš
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Phenyl Ring ◽  
Antimycobacterial Activity ◽  
Basic Structure ◽  
Subsequent Treatment ◽  
Imidazole Derivatives ◽  
Structure Activity ◽  
Antimycobacterial Agents

Abstractα-Amino acid-derived 2-phenylimidazole derivatives were designed, synthesized, and further investigated as potential antimycobacterial agents. The synthesis of target imidazole derivatives involved the transformation of Cbz-protected α-amino acids (Ala, Val, Phe, Leu, iLe, and Pro) into α-diazoketones and α-bromoketones, respectively. Subsequent treatment of α-bromoketones with (4-nitro)benzamidine afforded imidazole derivatives bearing α-amino acid residue appended to the imidazole C4 and (4-nitro)phenyl ring in the position C2. Antimycobacterial activities of both series of compounds against M. tuberculosis, M. avium, and M. kansasii were screened and basic structure-activity relationships were further evaluated.

Quantitative Structure-Activity Relationship Study of Radical Scavenging Peptides Based on Orac Method by Using Different Sets of Amino Acids Descriptor

2011 ◽  
Vol 365 ◽  
pp. 169-179 ◽  
Author(s):  
Yao Wang Li ◽  
Bo Li
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Predictive Ability ◽  
Peptide Sequence ◽  
Quantitative Structure ◽  
Least Squares Regression ◽  
Structure Activity ◽  
Amino Acid Descriptors

Some radical scavenging peptides by ORAC method from different hydrolysates were used for the quantitative structure-activity relationships (QSAR) research. Partial least-squares regression analysis (PLSR) was treated as the method to build the model with 17 kinds of amino acid descriptors. In order to translate the sequence to the same length, two-terminal position numbering (TTPN) was applied. Two of amino acid descriptors VSHE and VSW were selected for their excellent performance (R2, Q2, and RMSEcwith VHSE and VSW descriptor are 0.995, 0.630, 0.318 and 0.966, 0.543, 0.181 respectively). VHSE has the definite physicochemical meanings and easy to understand while VSW has good predictive ability (Rand RMSEpwith VHSE and VSW are 0.404, 2.633 and 0.635, 2.298 respectively). It is believed that the position No.2 amino acid from N-terminal (N2) have more importance than others in sequence, and most of electronic properties are negative to activity while all the steric properties are positive to activity as well as the hydrophobic properties. The suitable amino acids in sequence are as follow: G, R, K, W, Y, N, E, H, and Q are suitable for N2position which illustrated the importance of acidic amino acids in peptide sequence for radical scavenging activity.

scholarly journals N4-amino-acid derivatives of 6-azacytidine: structure-activity relationship.

2000 ◽  
Vol 47 (1) ◽  
pp. 95-101 ◽  
Author(s):  
I Alexeeva ◽  
L Palchikovskaya ◽  
A Shalamay ◽  
L Nosach ◽  
V Zhovnovataya ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antiviral Activity ◽  
Chemical Structure ◽  
Specific Activity ◽  
Biological Properties ◽  
Activity Relationship ◽  
Amino Acid Derivatives ◽  
Condensation Method ◽  
Structure Activity ◽  
Derivatives Of

Several N4-derivatives of 6-azacytidine were synthesized using of Vorbrüggen's condensation method. Their antiviral activity with respect to the adenovirus serotypes 2 and 5 in Hep-2 cells culture was studied and primary specific activity was determined. Correlation between chemical structure of new 6-azacytidine derivatives and their biological properties is discussed.

scholarly journals Quantitative Structure–Activity Relationship Study of Bitter Di-, Tri- and Tetrapeptides Using Integrated Descriptors

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2846 ◽  
Author(s):  
Xu ◽  
Chung
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Electronic Properties ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Partial Specific Volume ◽  
Quantitative Structure ◽  
Structure Activity ◽  
Terminal Amino

New quantitative structure–activity relationship (QSAR) models for bitter peptides were built with integrated amino acid descriptors. Datasets contained 48 dipeptides, 52 tripeptides and 23 tetrapeptides with their reported bitter taste thresholds. Independent variables consisted of 14 amino acid descriptor sets. A bootstrapping soft shrinkage approach was utilized for variable selection. The importance of a variable was evaluated by both variable selecting frequency and standardized regression coefficient. Results indicated model qualities for di-, tri- and tetrapeptides with R2 and Q2 at 0.950 ± 0.002, 0.941 ± 0.001; 0.770 ± 0.006, 0.742 ± 0.004; and 0.972 ± 0.002, 0.956 ± 0.002, respectively. The hydrophobic C-terminal amino acid was the key determinant for bitterness in dipeptides, followed by the contribution of bulky hydrophobic N-terminal amino acids. For tripeptides, hydrophobicity of C-terminal amino acids and the electronic properties of the amino acids at the second position were important. For tetrapeptides, bulky hydrophobic amino acids at N-terminus, hydrophobicity and partial specific volume of amino acids at the second position, and the electronic properties of amino acids of the remaining two positions were critical. In summary, this study not only constructs reliable models for predicting the bitterness in different groups of peptides, but also facilitates better understanding of their structure-bitterness relationships and provides insights for their future studies.

Structure-Activity Study of Tripeptide Thrombin Inhibitors Using .alpha.-Alkyl Amino Acids and Other Conformationally Constrained Amino Acid Substitutions

1995 ◽  
Vol 38 (22) ◽  
pp. 4446-4453 ◽  
Author(s):  
Robert T. Shuman ◽  
Robert B. Rothenberger ◽  
Charles S. Campbell ◽  
Gerald F. Smith ◽  
Donetta S. Gifford-Moore ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Thrombin Inhibitors ◽  
Amino Acid Substitutions ◽  
Conformationally Constrained ◽  
Structure Activity

N-Benzoyl amino acids as LFA-1/ICAM inhibitors 1: amino acid structure–activity relationship

2003 ◽  
Vol 13 (6) ◽  
pp. 1015-1018 ◽  
Author(s):  
Daniel J. Burdick ◽  
Ken Paris ◽  
Kenneth Weese ◽  
Mark Stanley ◽  
Maureen Beresini ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Structure Activity ◽  
Acid Structure ◽  
Amino Acid Structure

ISARIIN, A NEW DEPSIPEPTIDE FROM ISARIA CRETACEA

1962 ◽  
Vol 40 (8) ◽  
pp. 1579-1584 ◽  
Author(s):  
L. C. Vining ◽  
W. A. Taber
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Molar Ratio ◽  
Cyclic Structure ◽  
Terminal Amino Acid ◽  
Peptide Bonds ◽  
Metabolic Products ◽  
Ester Linkage ◽  
Terminal Amino

One of the metabolic products of the fungus Isaria cretacea has been found to yield four different amino acids and a hydroxyacid on acid hydrolysis. The amino acids were identified as glycine, L-alanine, L-valine, and D-leucine, and a quantitative analysis showed them to be present in the molar ratio of 1:1:2:1, respectively. The hydroxyacid was identified as D-β-hydroxydodecanoic acid. These units appear to be combined in a simple cyclic structure by means of peptide bonds and an ester linkage between the hydroxyl of hydroxydecanoic acid and the carboxyl of the C-terminal amino acid. The sequence valine → β-hydroxydodecanoic acid → glycine has been established.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

Sign in / Sign up

Export Citation Format

Share Document