Vinyl Glycine Research Articles

Effects of Aminoethoxy Vinyl Glycine (Avg) on Fruit Quality and Bioactive Content of Jujube Fruit (Ziziphus Jujuba) Harvested at Three Maturity Stages During Cold Storage

Effects of Aminoethoxy Vinyl Glycine (Avg) on Fruit Quality and Bioactive Content of Jujube Fruit (Ziziphus Jujuba) Harvested at Three Maturity Stages During Cold Storage

Dichromate-induced ethylene biosynthesis, perception, and signaling regulate the variance in root growth inhibition among Shaheen basmati and basmati-385 rice varieties.

Heavy metals, including a hexavalent form of chromium (Cr(VI)) increasing accumulation in agricultural soil, cause a significant reduction in quality, yield, and growth of rice varieties worldwide. Screening for the selection of tolerant varieties is essential for conventional and molecular breeding. Shaheen basmati (SB) and basmati-385 (B-385) rice varieties, a subspecies of indica, show different sensitivity to Cr(VI), but the underlying mechanisms of this different sensitivity remain elusive. In the current study, we examine the sensitivity of SB and B-385 based on the root, which is the primary organ that encounters water and soil containing Cr(VI), elongation assay, and ethylene's possible role (a stress-responsive phytohormone) in the process. Our results show that SB's seedlings exhibit hypersensitivity as a higher root elongation inhibition than B-385 under different Cr(VI) concentrations. Hypersensitive SB consistently expresses a higher level of ethylene biosynthesis and signaling-related genes than B-385. Moreover, ethylene signaling antagonist (silver, Ag) and biosynthesis inhibitor (aminoethoxy vinyl glycine, AVG) alleviate the difference in Cr(VI)-induced root growth inhibition between SB and B-385, respectively. Taken together, we conclude that ethylene mediates difference in sensitivity based on the difference in root growth inhibition in different rice varieties. The difference in Cr(VI)-induced root growth inhibition in SB and B-385. (A) Root growth of SB is slightly more as compared to B-385 in control conditions in the Hoagland solutions. (B) Seedlings of SB showed hypersensitivity to 200 μM Cr(VI) compared to B-385 in terms of primary root growth inhibition, which was higher in SB than B-385. Interestingly, Cr(VI)-induced relative transcript level of ethylene biosynthesis, perception, and signaling-related genes was significantly higher in hypersensitive SB than B-385. Current results in association with previous literature show that Cr(VI)-induced ethylene biosynthesis is regulating Cr(VI)-induced ethylene perception, signaling, and associated Cr(VI)-induced ethylene-mediated primary root growth inhibition. Conclusively, the difference in ethylene quantities in both varieties mediates the difference in root growth inhibition between SB and B-385 (C and E). The difference in Cr(VI)-induce root growth inhibition between SB and B-385 was significantly alleviated by ethylene signaling inhibitor (10 μM Ag, as AgNO3) and ethylene biosynthesis inhibitor (10 μM AVG) treatment in the presence of 200 μM Cr(VI), respectively. (D) Ethylene biosynthesis precursor (10 μM ACC) treatment-mediated induced root growth inhibition difference between SB and B-385 was not significant, which may be because of enough quantity of the Cr(VI)-mediated ethylene accumulation or unknown limiting factor. Arrows mean addition and an increase in expression, and T-line means suppression or inhibition. The width of the pointers (arrows) is proportional to the gene expression level.

The role of ethylene in abscission of sweet orange promoted by exogenous application of the abscission agent 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP)

ABSTRACTMature ‘Valencia’ fruit were treated with 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP), and the ethylene inhibitors aminoethoxy vinyl glycine (AVG) and silver thiosulfate (STS), to assess involvement of ethylene in abscission via CMNP. Fruit detachment force (FDF) and ethylene evolution were measured over time. Accumulation of the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC) in peel upon CMNP application was assessed and impact of application of ACC on FDF was estimated when applied 1 cm away from the abscission zone (AZ), to determine its potential as a signaling molecule in promoting fruit loosening. CMNP when applied alone reduced FDF by 50%. AVG and STS inhibited fruit loosening considerably at 500 µM and 10 mM, respectively, when applied with 2 mM CMNP. ACC accumulation in peel was highest 2 days after CMNP application, which preceded the maximum decline in FDF which occurred a day later, indicating that ACC serves as a potential signaling molecule that triggers abscission in the AZ. The results of the study support the hypothesis that abscission via CMNP application is at least partly ethylene dependent. However, the decline in FDF by ACC was less than 50% of control which suggested involvement of another pathway in abscission via CMNP in sweet orange.

Effects of ethylene on shoot initiation, leaf yellowing, and shoot tip necrosis in roses

This study was conducted to investigate the in vitro influence of ethylene on shoot branching and leaf yellowing in the rose cultivar Tineke by using different compounds that regulate ethylene inhibition and stimulation. Aminoethoxy vinyl glycine (AVG), silver thiosulfate (STS), and sodium nitroprusside (SNP) caused enhanced apical shoot initiation and reduced leaf yellowing, via inhibition of ethylene production, in the following order: AVG > SNP > STS. In contrast, the addition of 1-aminocyclopropane-1-carboxylic acid (ACC) or 3-indoleacetic acid (IAA) stimulated ethylene production and had greater negative effects on the studied parameters than the control; the negative effects of IAA were further confirmed in combination with AVG, STS, or SNP. The effects of ethylene on apical shoot initiation and leaf yellowing in Tineke were confirmed in another rose cultivar, Innocence. Hence, this study provides strong support for the hypothesis that ethylene-inhibiting agents have beneficial effects on apical shoot initiation and reduction of leaf yellowing in other rose cultivars.

2,3]-Sigmatropic Rearrangement of Allylic Selenimides: Strategy for the Synthesis of Peptides, Peptidomimetics, and N-Aryl Vinyl Glycines

The scope of the NCS-mediated amination/[2,3]-sigmatropic rearrangement of enantioenriched allylic selenides has been expanded to provide access to three new product classes. The use of N-protected amino acid amides provides a novel strategy for accessing peptide chains containing unnatural vinyl glycine amino acid residues. Also reported is the use of amino acid esters, allowing the diastereoselective synthesis of N,N-dicarboxymethylamines, a motif found in a number of pharmaceuticals. Furthermore, use of a range of N-aromatic and N-heteroaromatic amines allows the formation of enantioenriched N-arylamino acids, a motif found in a number of synthetically and biologically interesting compounds.

A Facile Synthesis of Fully Protected meso-Diaminopimelic Acid (DAP) and Its Application to the Preparation of Lipophilic N-Acyl iE-DAP

Synthesis of beneficial protected meso-DAP 9 by cross metathesis of the Garner aldehyde-derived vinyl glycine 1b with protected allyl glycine 2 in the presence of Grubbs second-generation catalyst was performed. Preparation of lipophilic N-acyl iE-DAP as potent agonists of NOD 1-mediated immune response from 9 is described.

ChemInform Abstract: Enantioselective Synthesis of α‐Alkyl, α‐Vinyl Amino Acids via [2,3]‐Sigmatropic Rearrangement of Selenimides.

Chiral α-alkyl,α-vinyl amino acids (quaternary vinyl glycine derivatives) are prepared with high levels of enantiomeric purity by [2,3]-sigmatropic rearrangement of allylic selenimides. The required trisubstituted allylic selenides are prepared by an organocatalytic α-selenenylation of aldehydes followed by Horner−Wadsworth−Emmons (HWE) olefination. Both (E)-and (Z)-geometrical isomers are available giving access to both enantiomers of the desired products.

Enantioselective Synthesis of α-Alkyl,α-Vinyl Amino Acids via [2,3]-Sigmatropic Rearrangement of Selenimides

Chiral α-alkyl,α-vinyl amino acids (quaternary vinyl glycine derivatives) are prepared with high levels of enantiomeric purity by [2,3]-sigmatropic rearrangement of allylic selenimides. The required trisubstituted allylic selenides are prepared by an organocatalytic α-selenenylation of aldehydes followed by Horner-Wadsworth-Emmons (HWE) olefination. Both (E)-and (Z)-geometrical isomers are available giving access to both enantiomers of the desired products.

Alternaria alternata f.sp. lycopersici and its toxin trigger production of H2O2 and ethylene in tomato.

Alternaria alternata f.sp. lycopersici was isolated from a naturally infected tomato plant and characterized. The pure culture of this isolate produced typical necrotic lesions on the leaves of tomato (Lycopersicon esculentum cv. CO-3). The isolated pathogen also secreted a phytotoxic compound into the culture filtrate. This filtrate, when infiltrated into tomato leaves, produced necrotic lesions identical to those produced by pure cultures of the pathogen. Excised tomato leaves showed a dose-response effect to increasing concentrations of culture filtrate. Pathogen infection and culture filtrate infiltration triggered H2O2 production and ethylene evolution from tomato leaves within 6 h of treatment, followed by necrosis of the treated leaves. Application of the antioxidant L-ascorbic acid suppressed the production of H2O2. Ethylene evolution was also significantly lowered by application of aminoethoxy vinyl glycine. Application of both these compounds also reduced the necrosis induced by Alternaria alternata f.sp. lycopersici and its culture filtrate.

Exploiting Organocatalysis: Enantioselective Synthesis of Vinyl Glycines by Allylic Sulfimide [2,3] Sigmatropic Rearrangement.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Concise Synthesis of Vinyl Glycines

Concise Synthesis of Vinyl Glycines

Exploiting Organocatalysis: Enantioselective Synthesis of Vinyl Glycines by Allylic Sulfimide [2,3] Sigmatropic Rearrangement

Exploiting Organocatalysis: Enantioselective Synthesis of Vinyl Glycines by Allylic Sulfimide [2,3] Sigmatropic Rearrangement

Exploiting Organocatalysis: Enantioselective Synthesis of Vinyl Glycines by Allylic Sulfimide [2,3] Sigmatropic Rearrangement

Freie Wahl: Enantiomerenangereicherte E-Vinylglycine lassen sich aus Aldehyden in einer einfachen Sequenz herstellen, die eine organokatalytische α-Sulfenylierung mit einer stereoselektiven Olefinierung, einer Sulfimidierung und einer [2,3]-sigmatropen Umlagerung kombiniert (siehe Schema, Boc=tert-Butoxycarbonyl, nHex=n-Hexyl). Über das Einstellen der Doppelbindungskonfiguration im Olefinierungsschritt sind beide Enantiomere zugänglich.

New unsaturated amino acids containing an allylsilane moiety on the lateral chain

New enantiomerically enriched polyfunctionalized allylsilanes have been obtained from the synthetic elaboration of naturally occurring serine. In particular, an oxazolidine bearing an allylsilane framework on the lateral chain proved to be a suitable precursor for the corresponding silylated vinyl glycine derivatives.

Prodrug forms of N-[(4-deoxy-4-amino-10-methyl)pteroyl]glutamate-gamma-[psiP(O)(OH)]-glutarate, a potent inhibitor of folylpoly-gamma-glutamate synthetase: synthesis and hydrolytic stability.

Ester prodrugs of the phosphinate pseudopeptide N-[(4-deoxy-4-amino-10-methyl)pteroyl]glutamate-gamma-[psiP(O)(OH)]-glutarate (1a) were synthesized. H-phosphinic acids derived from N-Cbz vinyl glycine esters were converted to the desired pseudopeptides by Michael addition to alpha-methyleneglutarate esters. Pivaloyloxymethyl (POM) ester moieties were incorporated in both the N-terminal and C-terminal fragments prior to formation of either C-P bond. N-Alkylation of the corresponding amides derived from p-(N-methyl)aminobenzoic acid with 2,4-diamino-6-(bromomethyl)pteridine gave the target compounds. POM esters of methotrexate and the corresponding gamma-glutamyl conjugate were also synthesized using the same strategy. All prodrugs were evaluated in Chinese hamster ovary cells. Although the pseudopeptide prodrugs were ineffective, prodrugs of methotrexate and the corresponding gamma-glutamyl conjugate were equipotent with the parent compounds. Stability of the prodrugs was investigated in both phosphate buffer and cell line medium to provide a rationale for the observed biological data.

Synthesis and Proinflammatory Properties of Muramyl Tripeptides Containing Lysine and Diaminopimelic Acid Moieties

The unusual amino acid diaminopimelic acid (DAP) was prepared by cross metathesis of appropriately protected vinyl glycine and allyl glycine derivatives. Catalytic hydrogenation of the cross-coupling product resulted in reduction of the double bond and the removal of protecting groups. The resulting compounds were appropriately protected for the polymer-supported and solution-phase synthesis of muramyl tripeptides 2 and 3, which differ in the amidation of the alpha-carboxylic acids of the isoglutamine and DAP moieties. Muramyl dipeptide (1, MDP), the DAP-containing muramyl tripeptide 3, and the lysine-containing muramyl tripeptides 4 and 5 induced TNF-alpha gene expression without TNF-alpha protein production in a human monocytic cell line. The observed block in translation could be removed by co-incubation with LPS, resulting in an apparent synergistic effect. Compound 2 did not induce TNF-alpha gene expression, neither did it exhibit a synergistic effect with LPS; this indicates that amidation of the alpha-carboxylic acids of the isoglutamine and DAP moieties results in a loss of biological activity. It is proposed that amidation of alpha-carboxylic acids is a strategy that may be used by pathogens to avoid detection by the innate immune system. Furthermore, the pattern recognition receptors Nod1 and Nod2 have been implicated in the possible induction of a synergistic effect of muropeptides with LPS.

A Stereoselective Synthesis of Phosphinic Acid Phosphapeptides Corresponding to Glutamyl-γ-glutamate and Incorporation into Potent Inhibitors of Folylpoly-γ-glutamyl Synthetase

Radical addition of H3PO2 to N-/C-protected vinyl glycine led to the corresponding H-phosphinic acid in excellent yield. The non-nucleophilic H-phosphinic acid was converted to a nucleophilic P(III) species, RP(OTMS)2, which was used in two approaches to the target phosphinic acid containing pseudopeptide. New methodology was developed that led to excellent yields in the reaction of RP(OTMS)2 with unactivated electrophiles, including an acyclic homoallylic bromide. However, en route to the target pseudopeptide, Arbuzov reaction of RP(OTMS)2 with a cyclic homoallylic bromide, (R)-3-(bromomethyl)-cyclopent-1-ene, led to a rearranged allylic phosphinic acid rather than the desired homoallylic derivative, a putative glutarate surrogate. Conjugate addition of RP(OTMS)2 to alpha-methylene glutarate containing a chiral auxiliary resulted in only modest diastereoselectivity. Purification by flash chromatography provided protected derivatives of both diastereomers of the pseudopeptide. Following global deprotection, coupling of (S)-H-Glu-gamma-[Psi(P(O)(OH)(CH2))]-(S)-Glu-OH and (S)-H-Glu-gamma-[Psi(P(O)(OH)(CH2))]-(R)-Glu-OH to (4-amino-4-deoxy-10-methyl)pteroyl azide led to the target compounds for biochemical study as inhibitors of the ATP-dependent ligase, folylpoly-gamma-glutamate synthetase.

The synthesis of diaminopimelic acid containing peptidoglycan fragments using metathesis cross coupling

Properly protected diaminopimelic acid (DAP), a component of peptidoglycan of Gram-negative bacteria, was prepared by a metathesis cross coupling between properly protected allyl and vinyl glycine derivatives using Grubb’s second-generation catalyst followed by reduction of the double bond of the resulting compound. The DAP derivatives were used in the solution- and polymer-supported synthesis of biological active peptides.

ChemInform Abstract: Ring Closing Metathesis of Vinyl Glycine Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Ring closing metathesis of vinyl glycine derivatives

Ring closing metathesis of vinyl glycine derivatives using Grubbs' ruthenium catalyst has been performed successfully. The reaction works well with N-allyl amides derived from N-protected vinyl glycines. The use of a trityl protecting group allows the reaction to be performed successfully with the otherwise unreactive N-allyl vinyl glycine ester.