Total synthesis of [
            15
            N]-labelled C6-substituted purines from [
            15
            N]-formamide—easy preparation of isotopically labelled cytokinins and derivatives

Cytokinins (CKs) and their metabolites and derivatives are essential for cell division, plant growth regulation and development. They are typically found at minute concentrations in plant tissues containing very complicated biological matrices. Therefore, defined standards labelled with stable isotopes are required for precise metabolic profiling and quantification of CKs, as well as in vivo elucidation of CK biosynthesis in various plant species. In this work, 11 [ 15 N]-labelled C6-purine derivatives were prepared, among them 5 aromatic ( 4, 5, 6, 7, 8 ) and 3 isoprenoid ( 9, 10, 11 ) CKs. Compared to current methods, optimized syntheses of 6-amino-9H-[ 15 N 5 ]-purine (adenine) and 6-chloro-9H-[ 15 N 4 ]-purine (6-chloropurine) were performed to achieve more effective, selective and generally easier approaches. The chemical identity and purity of prepared compounds were confirmed by physico-chemical analyses (TLC; HRMS; HPLC–MS; 1 H, 13 C, 15 N NMR). The presented approach is applicable for the synthesis of any other desired [ 15 N 4 ]-labelled C6-substituted purine derivatives.

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THYROID STIMULATORS AND THYROID STIMULATION

Acta Endocrinologica ◽

10.1530/acta.0.0660558 ◽

1971 ◽

Vol 66 (3) ◽

pp. 558-576 ◽

Cited By ~ 15

Author(s):

Gerald Burke

Keyword(s):

Regulatory System ◽

Control Site ◽

Thyroid Cell ◽

Primary Control ◽

Physico Chemical ◽

Site Of Action ◽

Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

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Development and Pharmacokinetics Study of Antifungal Peptide Nanoliposomes by Liquid Chromatography-tandem Mass Spectrometry

Current Pharmaceutical Analysis ◽

10.2174/1573412914666180307155328 ◽

2019 ◽

Vol 15 (4) ◽

pp. 312-318

Author(s):

Shuoye Yang

Keyword(s):

Mass Spectrometry ◽

Biological Properties ◽

Pharmacokinetic Property ◽

Antifungal Peptide ◽

Simple Liquid ◽

Physico Chemical ◽

Liquid Chromatography Tandem Mass ◽

Pegylated Lipids

Background: The therapeutic ability and application of antifungal peptide (APs) are limited by their physico-chemical and biological properties, the nano-liposomal encapsulation would improve the in vivo circulation and stability. </P><P> Objective: To develop a long-circulating liposomal delivery systems encapsulated APs-CGA-N12 with PEGylated lipids and cholesterol, and investigated through in vivo pharmacokinetics. Methods: The liposomes were prepared and characterized, a rapid and simple liquid chromatographytandem mass spectrometry (LC-MS/MS) assay was developed for the determination of antifungal peptide in vivo, the pharmacokinetic characteristics of APs liposomes were evaluated in rats. Results: Liposomes had a large, unilamellar structure, particle size and Zeta potential ranged from 160 to 185 nm and -0.55 to 1.1 mV, respectively. The results indicated that the plasma concentration of peptides in reference solutions rapidly declined after intravenous administration, whereas the liposomeencapsulated ones showed slower elimination. The AUC(0-∞) was increased by 3.0-fold in liposomes in comparison with standard solution (20 mg·kg-1), the half-life (T1/2) was 1.6- and 1.5-fold higher compared to the reference groups of 20 and 40 mg·kg-1, respectively. Conclusion: Therefore, it could be concluded that liposomal encapsulation effectively improved the bioavailability and pharmacokinetic property of antifungal peptides.

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Synthesis, Characterization, and Encapsulation of Novel Plant Growth Regulators (PGRs) in Biopolymer Matrices

International Journal of Molecular Sciences ◽

10.3390/ijms22041847 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1847

Author(s):

Kristina Vlahoviček-Kahlina ◽

Slaven Jurić ◽

Marijan Marijan ◽

Botagoz Mutaliyeva ◽

Svetlana V. Khalus ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Electrostatic Interactions ◽

Growth Regulation ◽

Field Experiments ◽

Dimethyl Ester ◽

Plant Growth Regulation ◽

Derivatives Of ◽

Growth Regulating Activity

Novel plant growth regulators (PGRs) based on the derivatives of dehydroamino acids 2,3-dehydroaspartic acid dimethyl ester (PGR1), Z-isomer of the potassium salt of 2-amino-3-methoxycarbonylacrylic acid (PGR2) and 1-methyl-3-methylamino-maleimide (PGR3) have been synthesized and their growth-regulating properties investigated. Laboratory testing revealed their plant growth-regulating activity. PGR1 showing the most stimulating activity on all laboratory tested cultures were used in field experiments. Results showed that PGR1 is a highly effective environmentally friendly plant growth regulator with effects on different crops. Biopolymeric microcapsule formulations (chitosan/alginate microcapsule loaded with PGR) suitable for application in agriculture were prepared and characterized. Physicochemical properties and release profiles of PGRs from microcapsule formulations depend on the molecular interactions between microcapsule constituents including mainly electrostatic interactions and hydrogen bonds. The differences in the microcapsule formulations structure did not affect the mechanism of PGRs release which was identified as diffusion through microcapsules. The obtained results opened a perspective for the future use of microcapsule formulations as new promising agroformulations with a sustained and target release for plant growth regulation.

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An insight into the determination of size and number concentration of silver nanoparticles in blood using single particle ICP-MS (spICP-MS): Feasibility of application to samples relevant to in vivo toxicology studies

Journal of Analytical Atomic Spectrometry ◽

10.1039/d1ja00068c ◽

2021 ◽

Author(s):

Isabel Abad-Álvaro ◽

Diego Leite ◽

Dorota Bartczak ◽

Susana Cuello ◽

Beatriz Gomez-Gomez ◽

...

Keyword(s):

Silver Nanoparticles ◽

Single Particle ◽

Number Concentration ◽

Biological Matrices ◽

Icp Ms ◽

Toxicological Studies ◽

Insight Into

Toxicological studies concerning nanomaterials in complex biological matrices usually require a carefully designed workflow that involves handling, transportation and preparation of a large number of samples without affecting the nanoparticle...

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Characterization of phase I and phase II metabolites of hop (Humulus lupulus L.) bitter acids: In vitro and in vivo metabolic profiling by UHPLC-Q-Orbitrap

Journal of Pharmaceutical and Biomedical Analysis ◽

10.1016/j.jpba.2021.114107 ◽

2021 ◽

pp. 114107

Author(s):

Emanuela Salviati ◽

Eduardo Sommella ◽

Albino Carrizzo ◽

Veronica Di Sarno ◽

Alessia Bertamino ◽

...

Keyword(s):

Phase I ◽

Phase Ii ◽

Metabolic Profiling ◽

Humulus Lupulus ◽

Humulus Lupulus L ◽

Bitter Acids ◽

Phase Ii Metabolites

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SlBBX20 interacts with the COP9 signalosome subunit SlCSN5-2 to regulate anthocyanin biosynthesis by activating SlDFR expression in tomato

Horticulture Research ◽

10.1038/s41438-021-00595-y ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Dan Luo ◽

Cheng Xiong ◽

Aihua Lin ◽

Chunli Zhang ◽

Wenhui Sun ◽

...

Keyword(s):

Growth Regulation ◽

Anthocyanin Biosynthesis ◽

Plant Stress ◽

Underlying Mechanism ◽

Bimolecular Fluorescence Complementation ◽

Cop9 Signalosome ◽

Anthocyanin Accumulation ◽

Related Transcription Factor ◽

Hybrid Screening

AbstractAnthocyanins play vital roles in plant stress tolerance and growth regulation. Previously, we reported that the photomorphogenesis-related transcription factor SlBBX20 regulates anthocyanin accumulation in tomato. However, the underlying mechanism remains unclear. Here, we showed that SlBBX20 promotes anthocyanin biosynthesis by binding the promoter of the anthocyanin biosynthesis gene SlDFR, suggesting that SlBBX20 directly activates anthocyanin biosynthesis genes. Furthermore, we found by yeast two-hybrid screening that SlBBX20 interacts with the COP9 signalosome subunit SlCSN5-2, and the interaction was confirmed by bimolecular fluorescence complementation and coimmunoprecipitation assays. SlCSN5 gene silencing led to anthocyanin hyperaccumulation in the transgenic tomato calli and shoots, and SlCSN5-2 overexpression decreased anthocyanin accumulation, suggesting thSlCSN5-2 enhanced the ubiquitination of SlBBX20 and promoted the degradation of SlBBX20 in vivo. Consistently, silencing the SlCSN5-2 homolog in tobacco significantly increased the accumulation of the SlBBX20 protein. Since SlBBX20 is a vital regulator of photomorphogenesis, the SlBBX20-SlCSN5-2 module may represent a novel regulatory pathway in light-induced anthocyanin biosynthesis.

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