Synthesis of α/β-Aromatic Peroxy Thiols Mediated by Iodine Source

Peroxygenated compounds have wide applications in various fields, including chemistry, pharmaceutical chemistry, medicine, and materials science. However, there is still a need for more efficient and environmentally friendly synthesis methods for such compounds. Herein, we investigated the two-step, one-pot, regioselective synthesis of α/β-aromatic peroxy thiols. We explored various substrates and solvents for the reaction and identified the optimal reaction conditions. We successfully obtained several peroxy thiols in moderate to good yields via the selective generation of effective intermediates of iodoalkyl peroxides at room temperature without the need for metal catalysts

Comparison of Leaf Proteomes of Cassava (<i>Manihot esculenta</i> Crantz) Cultivar NZ199 Diploid and Autotetraploid Genotypes

<div><p>Cassava polyploid breeding has drastically improved our knowledge on increasing root yield and its significant tolerance to stresses. In polyploid cassava plants, increases in DNA content highly affect cell volumes and anatomical structures. However, the mechanism of this effect is poorly understood. The purpose of the present study was to compare and validate the changes between cassava cultivar NZ199 diploid and autotetraploid at proteomic levels. The results showed that leaf proteome of cassava cultivar NZ199 diploid was clearly differentiated from its autotetraploid genotype using 2-DE combined MS technique. Sixty-five differential protein spots were seen in 2-DE image of autotetraploid genotype in comparison with that of diploid. Fifty-two proteins were identified by MALDI-TOF-MS/MS, of which 47 were up-regulated and 5 were down-regulated in autotetraploid genotype compared with diploid genotype. The classified functions of 32 up-regulated proteins were associated with photosynthesis, defense system, hydrocyanic acid (HCN) metabolism, protein biosynthesis, chaperones, amino acid metabolism and signal transduction. The remarkable variation in photosynthetic activity, HCN content and resistance to salt stress between diploid and autotetraploid genotypes is closely linked with expression levels of proteomic profiles. The analysis of protein interaction networks indicated there are direct interactions between the 15 up-regulation proteins involved in the pathways described above. This work provides an insight into understanding the protein regulation mechanism of cassava polyploid genotype, and gives a clue to improve cassava polyploidy breeding in increasing photosynthesis and resistance efficiencies.</p></div

2-D gel protein profiles of leaves from cassava NZ199 diploid (A) and autotetraploid genotypes (B) and wrapped 2-DE map from diploid and autotetraploid genotypes (C).

<p>The white and black arrows in pane C indicated proteins that showed detectable changes (>2.0-fold of the normalized volume) in abundance compared with those observed in the control; white indicated a down-regulated match, and black indicated an up-regulated match. Small boxes indicated the gel regions to be amplified to highlight clearly detectable spots in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone-0085991-g003" target="_blank">Fig. 3</a>.</p

Identification of differential proteins in cassava cultivar NZ199 leaves from autotetraploid and diploid genotypes.

<p>The spots showing differential expression (>2.0-fold of the normalized volume) were counted after gel analysis and manual editing with Delta2D software. Each value represents the mean <b>±</b> SE of triplicates. Protein spots whose abundance increased (+) or decreased (−) after polyploidy were shown. The numbers corresponded to the 2-DE gel in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone-0085991-g002" target="_blank">Fig. 2</a>.</p>a<p>. The numbers corresponded to the 2-DE gel in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone-0085991-g002" target="_blank">Fig. 2</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone-0085991-g003" target="_blank">3</a>.</p>b<p>, Expression change level in tetraploid genotype compared with diploid genotype,</p>c<p>, NCBI accession number.</p>d<p>, Probability-based MOWSE (molecular weight search) scores.</p>e<p>, The number of unique peptides identified by MS/MS, and individual ions scores are all identity or extensive homology (p<0.05).</p

The growth of <i>in vitro</i> plantlets of cassava NZ199 diploid and autotetraploid genotypes under salt stress.

<p>Values were means ± SE. Different capital letters in the same column indicated statistically significant differences according to Duncan test (P<0.01).</p

Functional categories of 52 differential proteins identified in cassava NZ199 autotetraploid leaves compared withdiploidgenotypes.

<p>Number of spots altered in the expression in the leaves of cassava autotetraploid genotype. Unknown proteins included those whose functions had not been described.</p

Western blotting of Rubisco, APX and PrxQ.

<p>The expression of Rubisco, APX and PrxQ in leaves of cassava NZ199 diploid (a) and autotetraploid (b) genotypes were detected by western blotting using antiRubisco-polyclonal antibody (AS07218), anti-APX antibody (AS08368) and anti-PrxQ antibody (AS05093) from Agrisera, respectively.</p

Biological networks generated for combination of twelve differential proteins.

<p>Fifteen differentially up-regulated proteins including ATP synthase subunit beta, alcohol dehydrogenase, beta-glucosidase, phosphoglycerate kinase, triose phosphate isomerase, RCA, Rubisco, APX2, CDSP3, peroxiredoxin, thioredoxin translation elongation factor, glutamate-ammonia ligase, chaperone and 14-3-3 in cassava autotetraploid genotypes were used to generate a protein-protein interaction network through Pathway Studio analysis. Regulation is marked as an arrow with R, Chemical Reaction as an arrow with C and Binding as an arrow without any marks. The entity table, relation table and reference table data were presented in in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone.0085991.s003" target="_blank">Tables S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone.0085991.s004" target="_blank">S2</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone.0085991.s005" target="_blank">S3</a>.</p

Amplification of small boxes from Fig. 2C to highlight detectable spots that represent differentially abundant expression.

<p>In I, II, and III: a, diploid genotype, b; autotetraploid genotype. White arrow indicated a down-regulated match, and black indicated an up-regulated match. The numbers correspond to the 2-DE gel in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085991#pone-0085991-g002" target="_blank">Fig. 2</a>.</p

Imaging pulse amplitude modulation of cassava leaves from NZ199 diploid and autotetraploid genotypes.

<p>A, diploid genotype; B, autotetraploid genotype; Parameters shown are Fv/Fm [maximal photosystem II (PSII) quantum yield], ΦPSII (effective PSII quantum yield) (at 185 µE m⁻² s⁻¹), and NPQ/4 (nonphotochemical quenching) (at 185 µE m⁻² s⁻¹). The color gradient provides a scale from 0 to 100% for assessing the magnitude of the parameters.</p