Basic helix-loop-helix (bHLH) gene family in rye (Secale cereale L.): genome-wide identification, phylogeny, evolutionary expansion and expression analyses.

BACKGROUND: Rye (Secale cereale), one of the drought and cold-tolerant crops, is an important component of the Triticae Dumortier family of Gramineae plants. Basic helix-loop-helix (bHLH), an important family of transcription factors, has played pivotal roles in regulating numerous intriguing biological processes in plant development and abiotic stress responses. However, no systemic analysis of the bHLH transcription factor family has yet been reported in rye. RESULTS: In this study, 220 bHLH genes in S. cereale (ScbHLHs) were identified and named based on the chromosomal location. The evolutionary relationships, classifications, gene structures, motif compositions, chromosome localization, and gene replication events in these ScbHLH genes are systematically analyzed. These 220 ScbHLH members are divided into 21 subfamilies and one unclassified gene. Throughout evolution, the subfamilies 5, 9, and 18 may have experienced stronger expansion. The segmental duplications may have contributed significantly to the expansion of the bHLH family. To systematically analyze the evolutionary relationships of the bHLH family in different plants, we constructed six comparative genomic maps of homologous genes between rye and different representative monocotyledonous and dicotyledonous plants. Finally, the gene expression response characteristics of 22 ScbHLH genes in various biological processes and stress responses were analyzed. Some candidate genes, such as ScbHLH11, ScbHLH48, and ScbHLH172, related to tissue developments and environmental stresses were screened. CONCLUSIONS: The results indicate that these ScbHLH genes exhibit characteristic expression in different tissues, grain development stages, and stress treatments. These findings provided a basis for a comprehensive understanding of the bHLH family in rye.

Antioxidant and In Vivo Hypoglycemic Activities of Ethanol Extract from the Leaves of Engelhardia roxburghiana Wall, a Comparative Study of the Extract and Astilbin.

The leaves of Engelhardia roxburghiana Wall (LERW) has been used as sweet tea in China throughout history. In this study, the ethanol extract of LERW (E-LERW) was prepared and the compositions were identified by HPLC-MS/MS. It indicates that astilbin was the predominant component in E-LERW. In addition, E-LERW was abundant in polyphenols. Compared to astilbin, E-LERW presented much more powerful antioxidant activity. The E-LERW also had stronger affinity with α-glucosidase and exerted more vigorous inhibitory effect on the enzyme. Alloxan-induced diabetic mice had significantly elevated glucose and lipid levels. Treatment with E-LERW at the medium dose (M) of 300 mg/kg could reduce the levels of glucose, TG, TC, and LDL by 16.64%, 12.87%, 32.70%, and 22.99%, respectively. In addition, E-LERW (M) decreased food intake, water intake, and excretion by 27.29%, 36.15%, and 30.93%, respectively. Moreover, E-LERW (M) therapy increased the mouse weight and insulin secretion by 25.30% and 494.52%. With respect to the astilbin control, E-LERW was more efficient in reducing the food and drink consumption and protecting pancreatic islet and body organs from alloxan-induced damage. The study demonstrates that E-LERW may be a promising functional ingredient for the adjuvant therapy of diabetes.

Amorphous Co-Mo-B Film: A High-Active Electrocatalyst for Hydrogen Generation in Alkaline Seawater.

The development of efficient electrochemical seawater splitting catalysts for large-scale hydrogen production is of great importance. In this work, we report an amorphous Co-Mo-B film on Ni foam (Co-Mo-B/NF) via a facile one-step electrodeposition process. Such amorphous Co-Mo-B/NF possesses superior activity with a small overpotential of 199 mV at 100 mA cm-2 for a hydrogen evolution reaction in alkaline seawater. Notably, Co-Mo-B/NF also maintains excellent stability for at least 24 h under alkaline seawater electrolysis.

Copper-catalyzed reactions of α,ß-unsaturated N-tosylhydrazones with diaryliodonium salts to construct N-arylpyrazoles and diaryl sulfones.

Herein, an economical copper-catalyzed reaction of α,ß-unsaturated N-tosylhydrazones with diaryliodonium salts to construct both N-arylpyrazoles and diaryl sulfones has been developed. Both the p-toluenesulfonyl anion and the 3-arylpyrazole intermediates were formed in situ from N-tosylhydrazones. Subsequently, the former reacted rapidly with diaryliodonium salts to give diaryl sulfones and aryl iodide intermediates, and the latter reacted with aryl iodide to give N-arylpyrazoles under copper-catalyzed conditions. Using unsymmetrical mesityl phenyliodonium salts as substrates, mesityl p-toluenesulfide was obtained as the major product. This reaction took full advantage of the "waste" part of substrates to form an extra diaryl sulfone.

Chemical Profiling and Antioxidant Evaluation of Paeonia lactiflora Pall. "Zhongjiang" by HPLC-ESI-MS Combined with DPPH Assay.

Paeonia lactiflora Pall. "Zhongjiang" is one of the four major medicinal P. lactiflora plants in China. In this research, a high-performance liquid chromatography (HPLC)-diode array detector (DAD)-electrospray ionization-mass spectrometry method was established to identify various components in the extracts of P. lactiflora "Zhongjiang" (root extract or RE, stem and leaf extract or SLE and flower extract or FE). A total of 40 compounds, including 19 monoterpenoid glycosides, five tannins, 10 phenolic acids and their esters, and six other compounds, were determined or temporarily inferred from RE (35 species), SLE (20 species) and FE (15 species). Antioxidant evaluation indicates among the monomer compounds, catechin, gallic acid and ethyl gallate showed strong antioxidant activity close to vitamin C, ascorbic acid (Vc). Paeoniflorin, albiflorin, benzoylpaeoniflorin and 6'-O-benzoylalbiflorin had certain antioxidant activities, which were much lower than Vc. Furthermore, 19, 15 and 15 antioxidant-reactive components were screened from RE, SLE and FE by using the 1,1-diphenyl-2- picrylhydrazyl (DPPH)-HPLC test results. Results indicated that the ethanol extracts of P. lactiflora "Zhongjiang" had strong antioxidant activity, and the antioxidant active material basis was mainly composed of phenolic acids and gallic acid tannins. The main components of P. lactiflora "Zhongjiang", monoterpenoid glycosides, had weak antioxidant capacity. Paeonia lactiflora stems, leaves and flowers were good sources of antioxidants.

Synthesis, Characterization of Spirocyclic λ3 -Iodanes and Their Application to Prepare 4,1-Benzoxazepine-2,5-diones and 1,3-Diynes.

Herein, a [3+2] cycloaddition of aza-oxyallylic cations with ethynylbenziodoxolones for synthesis of new λ3 -iodanes containing spirocyclic 4-oxazolidinone has been developed. This cyclic λ3 -iodanes display stability in air and excellent solubility in organic solvent. Using them as substrate, both the 4,1-benzoxazepine-2,5-diones and symmetrical 1,3-diynes derivatives were afforded in high yield under copper(I)-catalyzed conditions.

Cryptophycin-55/52 based antibody-drug conjugates: Synthesis, efficacy, and mode of action studies.

Cryptophycin-52 (CR52), a tubulin inhibitor, exhibits promising antitumor activity in vitro (picomolar level) and in mouse xenograft models. However, the narrow therapeutic window in clinical trials limits its further development. Antibody-drug conjugate (ADC), formed by coupling cytotoxic compound (payload) to an antibody via a linker, can deliver drug to tumor locations in a targeted manner by antibody, enhancing the therapeutic effects and reducing toxic and side effects. In this study, we aim to explore the possibility of CR52-based ADC for tumor targeted therapy. Due to the lack of a coupling site in CR52, its prodrug cryptophycin-55 (CR55) containing a free hydroxyl was synthesized and conjugated to the model antibody trastuzumab (anti-HER2 antibody drug approved by FDA for breast cancer therapy) via the linkers based on Mc-NHS and Mc-Val-Cit-PAB-PNP. The average drug-to-antibody ratios (DARs) of trastuzumab-CR55 conjugates (named T-L1-CR55, T-L2-CR55, and T-L3-CR55) were 3.50, 3.29, and 3.35, respectively. These conjugates exhibited potent cytotoxicity in HER2-positive tumor cell lines with IC50 values at low nanomolar levels (0.58-1.19 nM). Further, they displayed significant antitumor activities at the doses of 10 mg/kg in established ovarian cancer (SKOV3) and gastric cancer (NCI-N87) xenograft models without overt toxicities. Finally, the drug releases were analyzed and the results indicated that T-L3-CR55 was able to effectively release CR55 and further epoxidized to CR52, which may be responsible for its best performance in antitumor activities. In conclusion, our results demonstrated that these conjugates have the potential for tumor targeted therapy, which provides insights to further research the CR55/CR52-based ADC for tumor therapy.

A base-promoted cascade reaction of α,ß-unsaturated N-tosylhydrazones with o-hydroxybenzyl alcohols: highly regioselective synthesis of N-sec-alkylpyrazoles.

An efficient method for the synthesis of N-sec-alkylpyrazoles through a base-promoted cascade cyclization/Michael addition reaction of α,ß-unsaturated N-tosylhydrazones with ortho-hydroxybenzyl alcohols has been developed. The desired products containing di- or triaryl groups at the same carbon atom were afforded in good to excellent yields with excellent regioselectivities (>20 : 1). Moreover, a three-component reaction of ortho-hydroxybenzyl alcohols, α,ß-unsaturated N-tosylhydrazones and saturated N-tosylhydrazones also took place to afford pyrazoles in good yields. This reaction offers a new route to triarylmethanes with a simple operation and is applicable for large-scale synthesis.

Metal-Free Ring-Expansion Reaction of Six-membered Sulfonylimines with Diazomethanes: An Approach toward Seven-Membered Enesulfonamides.

A new metal-free, ring-expansion reaction of six-membered N-sulfonylimines with unstable diazomethanes, generated in situ from the N-tosylhydrazones, has been developed. This reaction delivers valuable seven-membered enesulfonamides by a Tiffeneau-Demjanov rearrangement and intramolecular proton transfer tautomerization process. Moreover, this ring-expansion reaction can be carried out in a one-pot fashion and scaled up to the gram scale by using aryl aldehydes, without the need to isolate the N-tosylhydrazone.

Enantio- and Diastereoselective Formal Hetero-Diels-Alder Reactions of Trifluoromethylated Enones Catalyzed by Chiral Primary Amines.

Enantioselective formal hetero-Diels-Alder reactions of trifluoromethylated enones and 2-amino-1,3-butadienes generated in situ from aliphatic acyclic enones and chiral primary amines are reported. The corresponding tetrahydropyran-4-ones are formed in up to 94 % yield and with up to 94 % ee. The reaction was carried out through a stepwise mechanism, including initial aminocatalytic aldol condensation of 2-amino-1,3-butadiene to the trifluoromethylated carbonyl group followed by an intramolecular oxa-Michael addition. Both NMR investigation and theoretical calculations on the transition state indicate that the protonated tertiary amine could effectively activate the carbonyl group of the trifluoromethyl ketone to promote the addition process through hydrogen-bonding interaction of N-H⋅⋅⋅F and N-H⋅⋅⋅O simultaneously, and thus provide a chiral environment for the approach of amino-1,3-butadienes to the activated trifluoromethyl ketone, resulting in high enantioselectivity.

Palladium-catalyzed asymmetric cycloadditions of vinylcyclopropanes and in situ formed unsaturated imines: construction of structurally and optically enriched spiroindolenines.

A palladium-catalyzed (3 + 2) cycloaddition of vinyl cyclopropane and α,ß-unsaturated imines generated in situ from aryl sulfonyl indoles is reported. The reaction proceeds with high diastereoselectivity to provide the optically enriched spirocyclopentane-1,3'-indolenines in up to 74% yield and with up to 97% ee, which contains an all-carbon quaternary center and two tertiary stereocenters. The reaction involves a first conjugate addition of the carbon anion of zwitterionic π-allylpalladium complex from vinyl cyclopropane to the in situ formed unsaturated imine followed by a palladium-catalyzed intramolecular C3-allylation of indole.

Eradication of growth of HER2-positive ovarian cancer with trastuzumab-DM1, an antibody-cytotoxic drug conjugate in mouse xenograft model.

OBJECTIVE: Ovarian cancer is 1 kind of a highly malignant gynecologic tumor, and current treatments have not achieved satisfactory effects. Human epidermal growth factor receptor 2 (HER2)-targeted therapies including trastuzumab and trastuzumab-DM1 (T-DM1) (antibody-cytotoxic drug conjugates) have been applied to treat HER2-overexpressing breast cancers in clinic. In the present study, we explored whether T-DM1 could effectively treat HER2-positive human ovarian carcinoma in vitro and in vivo. METHODS: HER2 expressions of 6 ovarian cancer cell lines and 2 breast carcinoma cell lines were validated, and the binding capacity of T-DM1 to HER2-positive ovarian cancer SKOV3 cells were analyzed by flow cytometry. Nude mice bearing intraperitoneal and subcutaneous SKOV3 xenografts were used to investigate the antitumor effect of T-DM1. RESULTS: High HER2 expressions in SKOV3 cell lines were detected. The binding capacity of T-DM1 to HER2-positive SKOV3 cells was in a similar manner comparing with trastuzumab. In vitro, T-DM1 showed strong growth inhibitory on SKOV3 cells, with IC50 values of 0.15 nmol/L. Nude mice bearing intraperitoneal and subcutaneous SKOV3 xenografts were used to investigate the antitumor effects of T-DM1 in vivo. In subcutaneous xenografts model, T-DM1 (30 mg/kg and 10 mg/kg) indicated significant anticancer effects. It is noteworthy that tumors were completely eradicated in the T-DM1 (30 mg/kg) group, and no regrowth was observed in a long time after the termination of the treatment. In the peritoneal xenograft model, tumor nodules in 3 of 7 mice were hardly observed in the abdominal cavity of mice after intraperitoneal injection of T-DM1 (30 mg/kg). At the same time, tumor nodules from the other 4 mice weighed on the average of only 0.07 g versus 1.77 g in control group. CONCLUSIONS: Our data showed that T-DM1 possessed promising antitumor effects on HER2-overexpressing ovarian cancer in mouse model, which provided valuable references for the future clinical trials.

Enantioselective [4 + 2] cycloaddition of cyclic N-sulfimines and acyclic enones or ynones: a concise route to sulfamidate-fused 2,6-disubstituted piperidin-4-ones.

A concise route to valuable sulfamate-fused 2,6-disubstituted piperidin-4-ones or 2,3-dihydropyridin-4(1H)-ones in good yield with high diastereo- and enantioselectivity is presented. The combination of chiral primary amine and o-fluorobenzoic acid efficiently promoted an asymmetric [4 + 2] cycloaddition reaction of N-sulfonylimines and enones or ynones. The cycloaddition reaction between cyclic N-sulfonylimines and ynones is first reported.

One-pot synthesis of optically enriched 2-piperidinones from aliphatic aldehydes and cyanoacrylamides.

A highly stereoselective one-pot reaction of aliphatic aldehydes and cyanoacrylamides has been developed. The one-pot reaction includes an organocatalytic Michael addition followed by an intramolecular hemiaminalization. After reduction, optically enriched 2-piperidinones with three contiguous chiral centers were obtained in up to 95% yield and 9:1 dr with 99% ee.

Highly enantioselective aldol reactions between acetaldehyde and activated acyclic ketones catalyzed by chiral primary amines.

Highly enantioselective cross-aldol reactions between acetaldehyde and activated acyclic ketones are reported for the first time. Various acyclic ketones, such as saturated and unsaturated keto esters, reacted with acetaldehyde in the presence of a chiral primary amine and a Brønsted acid to afford optically enriched tertiary alcohols in good yields and with excellent enantioselectivities. Trifluoromethyl ketones were tolerable under the reaction conditions, thereby affording the trifluoromethyl carbinol in good-to-excellent yields and enantioselectivities. Structural modification of the chiral amines from the same chiral source switched the stereoselectivity of the products. The utility of aldol chemistry was demonstrated in the brief synthesis of functionally enriched δ-lactones. Theoretical calculations on the transition-state structure indicated that the protonated tertiary amine could effectively activate the carbonyl group of a keto ester to promote the addition process through hydrogen-bonding interaction and, simultaneously, provide an appropriate attacking pattern for the approach of the keto ester to the enamine, which is formed from acetaldehyde and the chiral catalyst, on a particular face, resulting in high enantioselectivity.

Synthesis, characterization, and antitumor evaluation of the albumin-SN38 conjugate.

7-Ethyl-10-hydroxycamptothecin (SN38), the active metabolite of irinotecan, exerts a 100-fold to 1000-fold higher effect than irinotecan itself against several tumor cell lines. However, the water insolubility of SN38 has prevented its direct use as an antitumor drug in the clinic. To improve the water solubility and antitumor efficacy, SN38 was covalently attached to the only free sulfhydryl at cysteine-34 on the BSA site specifically through a thiol-binding linker to form a prodrug BSA-SN38 conjugate (BSA : SN38=1 : 1). The water solubility of this conjugate was similar to albumin using the current method. Also, SN38 loading in this conjugate became controllable. Size-exclusion chromatography purification and UV characterization of the SDS-PAGE electrophoresis product were carried out. Then, an MTT assay was carried out to test the antitumor effect of this conjugate on five colon cancer cell lines in vitro. The 72 h IC50 values of the BSA-SN38 conjugate ranged from 1.5 to 6.1 µmol/l. A colorectal peritoneal carcinomatosis model in mice was established to determine the intraperitoneal chemotherapy effect of the BSA-SN38 conjugate. The BSA-SN38 conjugate at an SN38 equivalent dose of 10 mg/kg/day was administrated every 4 days. Eighteen days after manipulation, the mice were euthanized and the tumors in the abdominal cavity were collected and weighed. Tumors in the BSA-SN38 conjugate treatment group (m=0.21 ± 0.15 g) were found to be significantly (P=5) lighter than those in the NS control group (m=4.74±0.73 g). The results indicated that this water-soluble BSA-SN38 conjugate exerted a strong antitumor effect on colorectal carcinoma.

(E)-2-[1-(4-Fluoro-phen-yl)pent-1-en-3-yl-idene]malononitrile.

The title mol-ecule, C(14)H(11)FN(2), is approximately planar except the ethyl group, the maximum atomic deviation being 0.105 (5) Å. The fluoro-phenyl ring and 2-propyl-idene-malononitrile unit are located on the opposite sides of the C=C double bond, showing an E configuration.

(E)-2-[4-(2-Chloro-phen-yl)but-3-en-2-yl-idene]malononitrile.

There are two independent but virtually identical mol-ecules in the asymmetric unit of the title compound, C(13)H(19)ClN(2). Each mol-ecular skeleton displays an approximately planar structure except for the methyl group [the r.m.s. deviations for all 16 non-H atoms are 0.039 (mol-ecule 1) and 0.056 Š(mol-ecule 2)]. An E configuration is found about each of the C=C bonds. The crystal packing is stabilized by C-H⋯N inter-actions that connect the independent mol-ecules into supra-molecular chains along the c-axis direction.

Diastereoselective and enantioselective capture of chiral zinc enolate using nitroolefins: a rapid access to chiral γ-nitro carbonyl compounds.

Highly diastereoselective and enantioselective catalytic capture of chiral zinc enolates using nitroolefins as electrophiles is described. The tandem products γ-nitro ketones were obtained in good yields with high diastereoselectivities and enantioselectivities. The γ-nitro ketones were readily hydrogenated to the optically enriched and diastereomerically pure chiral pyrrolidines with four contiguous stereocentres under mild conditions.