A Highly Active Ruthenium(II) Pyrazolyl–Pyridyl–Pyrazole Complex Catalyst for Transfer Hydrogenation of Ketones

Ruthenium­(II) complexes bearing a pyrazolyl–pyridyl–pyrazole ligand were synthesized and exhibited exceptionally high catalytic activity in the transfer hydrogenation of ketones in refluxing isopropyl alcohol, reaching final TOFs up to 720 000 h^–1. The β-NH functionality of the pyrazole arm in the ligand demonstrated a remarkable acceleration effect on the reaction rate. The unsymmetrical nature (hemilability) and presence of the convertible NH group of the ligand is attributed to the high catalytic activity of the complex catalyst

Foster care and its forms with respect to the SOS Children's Villages

BLAST results of seven B-located gene fragments. (XLSX 11 kb

Additional file 9: Figure S4. of B chromosome contains active genes and impacts the transcription of A chromosomes in maize (Zea mays L.)

Sequencing graph of PCR products of four A and B chromosome homologous gene fragments. The arrows indicate the double peaks of SNP sites, and the arrowheads indicate the insertion/deletion sites, the double peaks appear on the upstream/downstream of the InDel sites. (TIF 3434 kb

Chlorophyll Deficiency in the Maize <i>elongated mesocotyl2</i> Mutant Is Caused by a Defective Heme Oxygenase and Delaying Grana Stacking

<div><p>Background</p><p>Etiolated seedlings initiate grana stacking and chlorophyll biosynthesis in parallel with the first exposure to light, during which phytochromes play an important role. Functional phytochromes are biosynthesized separately for two components. One phytochrome is biosynthesized for apoprotein and the other is biosynthesized for the chromophore that includes heme oxygenase (HO).</p> <p>Methodology/Principal Finding</p><p>We isolated a <i>ho1</i> homolog by map-based cloning of a maize <i>elongated</i><i>mesocotyl2</i> (<i>elm2</i>) mutant. cDNA sequencing of the <i>ho1</i> homolog in <i>elm2</i> revealed a 31 bp deletion. De-etiolation responses to red and far-red light were disrupted in <i>elm2</i> seedlings, with a pronounced elongation of the mesocotyl. The endogenous HO activity in the <i>elm2</i> mutant decreased remarkably. Transgenic complementation further confirmed the dysfunction in the maize <i>ho1</i> gene. Moreover, non-appressed thylakoids were specifically stacked at the seedling stage in the <i>elm2</i> mutant.</p> <p>Conclusion</p><p>The 31 bp deletion in the <i>ho1</i> gene resulted in a decrease in endogenous HO activity and disrupted the de-etiolation responses to red and far-red light. The specific stacking of non-appressed thylakoids suggested that the chlorophyll biosynthesis regulated by <i>HO1</i> is achieved by coordinating the heme level with the regulation of grana stacking.</p> </div

De-etiolation responses in Zheng58 wild-type plants and <i>elm2</i> mutants.

<p>Representative seedlings were photographed after 7 d of growth in continuous darkness (A), white light (B), red light (C), far-red light (D) or blue light (E) conditions. Left, Zheng58 wild-type seedlings; Right, <i>elm2</i> mutants. Scale bar=1 cm.</p

Electron microscope images of chloroplast structures.

<p>A and C, Zheng58 wild-type plants at the seedling and tasseling stages, respectively; B and D, <i>elm2</i> mutant plants at the seedling and tasseling stages, respectively. Scale bar=500 nm.</p

Statistical measurement of mesocotyl length in Zheng58 wild-type plants and <i>elm2</i> mutant plants.

<p>Zheng58 wild-type seedlings and mutant <i>elm2</i> seedlings were grown for 7 d in continuous darkness, white light, red light, far-red light, or blue light conditions. The sample size was 16-18 seedlings per treatment/genotype. Asterisk indicates significant difference as compared with Zheng58 wild-type at <i>P</i><0.01 (Student’s <i>t</i> test).</p

Pd-Catalyzed C‑7 Arylation of Indolines with Aryltriazenes under Mild Conditions

A palladium-catalyzed direct C–H arylation of indolines at C-7 position has been achieved at near-ambient temperature. The reaction was carried out with aryltriazene as a stable aryl source and electron shuttle to sustainably release aryl radical in situ under the action of promoter, and pyrimidine as a detachable directing group for the synthesis of 7-arylindolines under oxidant- and ligand-free conditions. Notably, this catalytic system can also be applied to the direct and site-selective arylation of tetrahydroquinolines (C-8) and carbazoles (C-1)

Exploration of Pyrrolobenzodiazepine (PBD)-Dimers Containing Disulfide-Based Prodrugs as Payloads for Antibody–Drug Conjugates

A number of cytotoxic pyrrolobenzodiazepine (PBD) monomers containing various disulfide-based prodrugs were evaluated for their ability to undergo activation (disulfide cleavage) <i>in vitro</i> in the presence of either glutathione (GSH) or cysteine (Cys). A good correlation was observed between <i>in vitro</i> GSH stability and <i>in vitro</i> cytotoxicity toward tumor cell lines. The prodrug-containing compounds were typically more potent against cells with relatively high intracellular GSH levels (e.g., KPL-4 cells). Several antibody–drug conjugates (ADCs) were subsequently constructed from PBD dimers that incorporated selected disulfide-based prodrugs. Such HER2 conjugates exhibited potent antiproliferation activity against KPL-4 cells <i>in vitro</i> in an antigen-dependent manner. However, the disulfide prodrugs contained in the majority of such entities were surprisingly unstable toward whole blood from various species. One HER2-targeting conjugate that contained a thiophenol-derived disulfide prodrug was an exception to this stability trend. It exhibited potent activity in a KPL-4 <i>in vivo</i> efficacy model that was approximately three-fold weaker than that displayed by the corresponding parent ADC. The same prodrug-containing conjugate demonstrated a three-fold improvement in mouse tolerability properties <i>in vivo</i> relative to the parent ADC, which did not contain the prodrug