The plant peptide hormone phytosulfokine promotes somatic embryogenesis by maintaining redox homeostasis in Cunninghamia lanceolata.

Somatic embryogenesis (SE) is widely used for studying the mechanisms of embryo development. However, little is known about the underlying mechanisms, especially in woody plants. Previous studies have established an SE system for Chinese fir (Cunninghamia lanceolata), but this system is genotype-dependent, which limits its application in practice. Here, we found that phytosulfokine (PSK), a plant peptide hormone, can not only increase SE efficiency, but also establish SE in recalcitrant genotypes of C. lanceolata. Proembryogenic mass (PEM) browning and determination of hydrogen peroxide (H2 O2 ) content by 2',7'-dichlorofluorescein staining indicated that a reactive oxygen species (ROS) burst occurred rapidly after PEMs were transferred to SE induction medium. Transcriptome analysis and quantitative reverse transcriptase-PCR validation showed that PSK treatment helped to maintain ROS homeostasis by decreasing the activity of peroxidases in early SE induction. This PSK-regulated redox microenvironment might be helpful to induce expression of SE-related genes like WOX2 in early SE induction. Further analyses suggested that PSK promotes SE induction in C. lanceolata partially through decreasing H2 O2 levels, which is necessary but not sufficient for SE induction in recalcitrant genotypes of C. lanceolata. Furthermore, heterologous overexpression of ClPSK in Arabidopsis led to enhanced SE induction and resistance to H2 O2 stress. Taken together, our study reveals a biological function for the plant peptide hormone PSK, extends our knowledge about SE in woody trees, and provides a valuable tool for establishing an efficient and genotype-independent SE system in C. lanceolata and other coniferous trees.

BPO-promoted [4 + 2] cyclization of enaminones and o-phenylenediamines to 2-acyl quinoxalines via a cascade transamination and C-H amination.

Rapid assembly of quinoxalines in a single step from readily available precursors has been recognized as an ideal platform in terms of efficiency and operation. Herein, we report a BPO-promoted metal-free approach to 2-acyl quinoxalines from enaminones and o-phenylenediamines via cascade transamination and C-H amination. This methodology demonstrates excellent compatibility with various substrates, including o-hydroxy enaminones, drug derivatives and natural products under mild reaction conditions.

Phytosulfokine contributes to suspension culture of Cunninghamia lanceolata through its impact on redox homeostasis.

BACKGROUND: Suspension culture is widely used in the establishment of efficient plant regeneration systems, as well as in the mass production of plant secondary metabolites. However, the establishment of a suspension culture system of Cunninghamia lanceolata is genotype-dependent given that proembryogenic masses (PEMs) are prone to browning during this process in recalcitrant genotypes. Previously, we reported that the plant peptide hormone phytosulfokine (PSK) can tremendously decrease the hydrogen peroxide (H2O2) level and help to initiate somatic embryogenesis (SE) in recalcitrant C. lanceolata genotypes. However, to date, no studies have revealed whether or how PSK may contribute to the establishment of a suspension culture system in these recalcitrant genotypes. RESULTS: Here, we demonstrated that exogenous application of PSK effectively inhibited PEM browning during suspension culture in a recalcitrant genotype of C. lanceolata. Comparative time-series transcriptome profiling showed that redox homeostasis underwent drastic fluctuations when PEMs were cultured in liquid medium, while additional PSK treatment helped to maintain a relatively stable redox homeostasis. Interestingly, PSK seemed to have a dual effect on peroxidases (PRXs), with PSK simultaneously transcriptionally repressing ROS-producing PRXs and activating ROS-scavenging PRXs. Furthermore, determination of H2O2 and MDA content, as well as cell viability, showed that exogenous PSK treatment inhibited PEM browning and safeguarded PEM suspension culture by decreasing the H2O2 level and increasing PEM activity. CONCLUSIONS: Collectively, these findings provide a valuable tool for the future establishment of large-scale C. lanceolata PEM suspension culture without genotype limitations.

Visible-light-induced C(sp3)-H thiocyanation of pyrazolin-5-ones: a practical synthesis of 4-thiocyanated 5-hydroxy-1H-pyrazoles.

A direct, aerobic and visible light photocatalytic approach to synthesize 4-thiocyanated 5-hydroxy-1H-pyrazoles via cross-coupling of pyrazolin-5-ones with ammonium thiocyanate is described. Under redox-neutral and metal-free conditions, a series of 4-thiocyanated 5-hydroxy-1H-pyrazoles could be easily and efficiently obtained in good to high yields by using low-toxicity and inexpensive ammonium thiocyanate as the thiocyanate source.

The Transcriptome of Cunninghamia lanceolata male/female cone reveal the association between MIKC MADS-box genes and reproductive organs development.

BACKGROUND: Cunninghamia lanceolata (Chinese fir), a member of the conifer family Cupressaceae, is one of the most popular cultivated trees for wood production in China. Continuous research is being performed to improve C. lanceolata breeding values. Given the high rate of seed abortion (one of the reasons being the failure of ovule and pollen development) in C. lanceolata, the proper formation of female/male cones could theoretically increase the number of offspring in future generations. MIKC MADS-box genes are well-known for their roles in the flower/cone development and comprise the typical/atypical floral development model for both angiosperms and gymnosperms. RESULTS: We performed a transcriptomic analysis to find genes differentially expressed between female and male cones at a single, carefully determined developmental stage, focusing on the MIKC MADS-box genes. We finally obtained 47 unique MIKC MADS-box genes from C. lanceolata and divided these genes into separate branches. 27 out of the 47 MIKC MADS-box genes showed differential expression between female and male cones, and most of them were not expressed in leaves. Out of these 27 genes, most B-class genes (AP3/PI) were up-regulated in the male cone, while TM8 genes were up-regulated in the female cone. Then, with no obvious overall preference for AG (class C + D) genes in female/male cones, it seems likely that these genes are involved in the development of both cones. Finally, a small number of genes such as GGM7, SVP, AGL15, that were specifically expressed in female/male cones, making them candidate genes for sex-specific cone development. CONCLUSIONS: Our study identified a number of MIKC MADS-box genes showing differential expression between female and male cones in C. lanceolata, illustrating a potential link of these genes with C. lanceolata cone development. On the basis of this, we postulated a possible cone development model for C. lanceolata. The gene expression library showing differential expression between female and male cones shown here, can be used to discover unknown regulatory networks related to sex-specific cone development in the future.

Preparation of Large-Size, Superparamagnetic, and Highly Magnetic Fe3O4@PDA Core⁻Shell Submicrosphere-Supported Nano-Palladium Catalyst and Its Application to Aldehyde Preparation through Oxidative Dehydrogenation of Benzyl Alcohols.

Large-size, superparamagnetic, and highly magnetic Fe3O4@PDA core-shell submicrosphere-supported nano-palladium catalysts were prepared in this study. Dopamine was encapsulated on the surface of Fe3O4 particles via self-polymerization and then protonated to positively charge the microspheres. PdCl42- was dispersed on the surface of the microspheres by positive and negative charge attraction and then reduced to nano-palladium. With air as oxidant, the catalyst can successfully catalyze the dehydrogenation of benzyl alcohols to produce the corresponding aldehydes at 120 °C.

Synthesis of α-keto imides through copper-catalyzed oxidation of N-sulfonyl ynamides.

A novel copper-catalyzed N-oxide oxidation of N-sulfonyl ynamides is disclosed. This non-noble metal-catalyzed protocol enables facile and efficient access to valuable α-keto imides in generally good to excellent yields. Other notable features of this method include widespread availability of the substrates, compatibility with broad functional groups, a simple procedure, mild conditions, and in particular, no need to exclude moisture or air ("open flask").

Compartmental approach to assess bioequivalence compared to the noncompartmental approach.

OBJECTIVE: The objective of this study is to evaluate the relative performance of individual or population compartmental analysis (ICA or PCA) vs. noncompartmental analysis (NCA) in estimating the systemic exposures of drugs to assess bioequivalence (BE) between original and generic formulations in the case of limited datasets. METHODS: BE study data of adefovir, finasteride, and tiropramide were chosen. The analyses were performed for the 1) original dataset, 2) limited dataset with small size for which the number of subjects was decreased to half, and 3) limited dataset with minimal-sampling timepoint of 9 samples. As for NCA and ICA, the Cmax and AUCinf were estimated using WinNonlin®. The PCA was implemented in NONMEM® and then Monte Carlo simulation was utilized to generate 10,000 sets of Cmax and AUCinf. RESULTS: The 90% confidence intervals (CIs) of the original datasets of the 3 drugs were all within BE acceptance criteria regardless of the analysis method. For small-sample-size datasets of adefovir and finasteride, BE results were maintained. In tiropramide, the lower boundary of CI computed from ICA or PCA results was less than 0.800 for the 3 small sample sizes (n = 22, 16, 10), but that of NCA results was less than 0.800 for only the smallest sample size (n = 10). As for the minimal-sampling timepoint, results were within the BE acceptance criteria for all of the 3 analyses. CONCLUSIONS: Compartmental approaches can provide a complementary method for BE assessment, as well as being used for restricted-design studies.

COMPARATIVE BIOAVAILABILITY OF A FIXED-DOSE COMBINATION TABLET OF OLMESARTAN MEDOXOMIL/HYDROCHLOROTHIAZIDE IN HEALTHY KOREAN VOLUNTEERS.

Combination therapy with diuretics and angiotensin II type 1 (AT1) receptor antagonist is frequently recommended for the control of blood pressure in hypertensive patients. This study was targeted to compare pharmacokinetic profiles of a new generic fixed-dose combination (FDC) tablet of olmesartan medoxomil/hydrochlorothiazide 20/12.5 mg and a reference formulation of Olmetec Plus 20/12.5 mg tablets in healthy volunteers. The study design was a randomized sequence and two-way crossover study in healthy subjects. They were to be randomly assigned to either one of the two sequence groups; each subject sequentially received a single oral dose of reference and test tablet with 7-day washout period. Blood sample was collected at pre-dose and at 0.33, 0.67, 1, 1.33, 1.67, 2, 2.5, 3, 4, 6, 8, 12, 24, 36 and 48 h post-dose. The blood concentrations were analyzed by LC-MS/MS. Both of the 90% CI for the treatment ratios (test/reference) of C(max) and AUC(last) were to be in the range of 0.800-1.250 with regards to olmesartan medoxomil and hydrochlorothiazide; the geometric mean ratios (test/reference) for olmesartan C(max) and AUC(last) were 0.979 (90% CI, 0.934-1.027) and 0.992 (0.946-1.041), respectively, and those for hydrochlorothiazide C(max) and AUC(last) were 0.966 (0.975-1.110) and 0.999 (0.963-1.038), respectively. No serious adverse events were reported during the study. The generic formulation of olmesartan medoxomil/hydrochlorothiazide 20/12.5 mg tablet was bioequivalent with the reference formulation of Olmetec Plus 20/12.5 mg tablet in regards to the pharmacokinetic parameters of olmesartan medoxomil and hydrochlorothiazide. Clinical Research Information Service (CRIS) Registration Number: KCT0001025. (https://cris.nih.go.kr/ Mar 18, 2014)

Pharmacokinetic comparisons of two acetyl-L-carnitine formulations in healthy Korean volunteers.

BACKGROUND: Acetyl-L-carnitine (ALC) has demonstrated neuroprotective effects in several experiments and is widely prescribed to reduce cognitive impairment in Alzheimer's disease patients or manage neuropathic symptoms in diabetic patients. OBJECTIVES: This study was designed to assess the pharmacokinetic (PK) bioequivalence between a new generic (test) formulation of ALC hydrochloride 590 mg and a branded (reference) formulation of ALC hydrochloride 590 mg in healthy Korean male volunteers. METHODS: This was a randomizedsequence, single-dose, two-way crossover study. All subjects randomly received one formulation of the test or reference tablet and the other formulation with a 7-day washout period. Blood samples (7 mL) were collected immediately before dosing, and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, and 12 hours postdose. The plasma concentrations of ALC were analyzed using liquid chromatography tandem mass spectrometry. Tolerability was assessed throughout the study. RESULTS: The PK profiles of both formulations showed similar rends. The mean (±SD) baseline (predose) concentration of ALC was 1.23±0.31 µg/mL and 1.09±0.30 µg/mL for the test and the reference formulations, respectively. The mean Cmax for the test and reference formulations were 1.74±0.43 µg/mL and 1.68±0.48 µg/mL, respectively. The mean AUClast of ALC was 12.96±1.89 µg×h/mL and 12.49±2.44 µg×h/mL for the test and reference formulations, respectively. The geometric mean ratios of test/reference (90% CI) were 1.050 (0.960-1.149) for Cmax and 1.048 (1.000-1.099) for AUClast. Both formulations were well tolerated in all treatment groups. CONCLUSION: The test and the reference formulations of ALC were bioequivalent with regard to the PK parameters.

Cell synchronization and isolation of chromosomes from Chinese fir root tips for flow cytometric analysis.

OBJECTIVES: To optimize treatment parameters to synchronize the cell cycle of Chinese fir root tip meristem cells. RESULTS: Optimal mitotic indices were achieved by treating seedlings with 1.25 mM hydroxyurea for 10 h, incubating for 7 h without chemical treatment to release the hydroxyurea block, and then treating emerging roots with 0.05 % colchicine for 16 h. The mitotic index of synchronized Chinese fir root tips was over 30 %. Suspensions of intact chromosomes were prepared using a simple slicing procedure. CONCLUSIONS: The chromosome preparations were suitable for flow cytometric characterization and sorting. The chromosome peaks of the observed flow karyotype resembled the predicted flow karyotype calculated from the Chinese fir chromosome size.

ClRTL1 Encodes a Chinese Fir RNase III-Like Protein Involved in Regulating Shoot Branching.

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named "Dugansha" (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique and an effective strategy to screen genes that potentially regulate shoot branching in Chinese fir using this mutant. An RNase III-like1 cDNA fragment named ClRTL1 was identified as a potential positive regulator. To investigate the function of ClRTL1 in regulating shoot branching, we cloned the full-length cDNA sequence from C. lanceolata (Lamb.) Hook, deduced its secondary structure and function, and overexpressed the coding sequence in Arabidopsis. The ClRTL1 cDNA is 1045 bp and comprises an open reading frame of 705 bp. It encodes a protein of 235 amino acids. The deduced secondary structure of the ClRTL1 indicates that it is a mini-RNase III-like protein. The expression analysis and phenotypes of 35S: ClRTL1 in A. thaliana implies that ClRTL1 plays a role in promoting shoot branching in Chinese fir.

Pharmacokinetic and bioequivalence assessment of two formulations of tianeptine sodium in healthy male volunteers.

BACKGROUND: Tianeptine is widely used for controlling depressive symptoms. OBJECTIVE: The aim of this study was to evaluate the bioequivalence between the generic (test) formulation containing tianeptine sodium 12.5 mg and the branded (reference) formulation Stablon® with regard to their pharmacokinetic profiles. METHODS: A randomized, two-sequence, two-treatment crossover study was conducted in healthy male Korean volunteers. All of the enrolled subjects were allocated to one of two sequence groups. They were administered a tablet of the test or reference formulation and then administered the alternative formulation after a 7-day washout period. The blood samples were taken before dosing and at 0.33, 0.67, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, and 10 hours after dosing. The plasma concentrations of tianeptine were analyzed using high-performance liquid chromatography with tandem mass spectrometer. Tolerability was assessed throughout the study. RESULTS: The pharmacokinetic parameters were assessed in the 40 subjects who completed the study. The tianeptine C(max) for the test formulation was 283.13 ± 57.58 ng/mL (mean ± SD) and that for the reference formulation was 272.50 ± 59.00 ng/mL. The AUC(last) of tianeptine was 803.24 ± 180.94 ng×h/mL for the test formulation and 792.27 ± 180.93 ng×h/mL for the reference formulation. The geometric mean ratio (%) of the test to reference formulation was 104.04 (90% CI, 99.66 - 108.61) for C(max) and 101.30 (98.01 - 104.71) for AUC(last). Clinically significant adverse events were not reported during the study. CONCLUSION: The test and reference formulations of tianeptine were bioequivalent with regard to the pharmacokinetic parameters of Cmax and AUC(last). Both formulations were tolerated by all of the participants.

Pharmacokinetics and bioequivalence of sildenafil granules and sildenafil tablets in Korean healthy volunteers.

BACKGROUND: A sildenafil tablet formulation as a PDE-5 inhibitor is widely used for the treatment of erectile dysfunction. Recently, a fine granular formulation of sildenafil was developed by a domestic Korean pharmaceutical company. OBJECTIVES: This study was performed to compare the bioavailability of sildenafil fine granules with that of sildenafil tablets for assessing bioequivalence in 40 healthy male volunteers. METHODS: This was an open-label, randomized sequence, single-dose, two-period, and two-treatment crossover study. Half of the volunteers received a single dose of sildenafil fine granule 50 mg and then sildenafil tablet 50 mg after a 7-day washout period. The remaining half of volunteers received the tablet first and the the granule with the same washout period. 10- mL blood samples were serially sampled to measure the concentrations of sildenafil and the N-desmethyl metabolite. Tolerability was assessed during the study. RESULTS: The pharmacokinetic parameters of sildenafil were similar between granular and tablet formulations. The 90% CI of geometric mean ratios (sildenafil granule/tablet) for the pharmacokinetic parameters of sildenafil were within 0.8 – 1.25, as a bioequivalent acceptable range; 1.111 (90% CI, 1.002 - 1.231) for maximum plasma concentration (Cmax) and 1.092 (1.019 - 1.117) for area under the concentration- time curve from time zero to time of last measurable concentration (AUClast). Also, the 90% CI of geometric mean ratios for Cmax and AUClast of the metabolite were within 0.8 - 1.25. Both formulations were well tolerated by volunteers. CONCLUSION: This study confirmed that sildenafil granules and sildenafil tablet are bioequivalent with regards to pharmacokinetics of sildenafil and N-desmethyl sildenafil.

Pharmacokinetic evaluation of a newly developed piperazine dithioctate formulation in healthy volunteers.

BACKGROUND: The formulation investigated as reference contains thioctic acid which is known to be poorly soluble in water and have some instability during storage at high temperature. To overcome these limitations, a new piperazine dithioctate (PDT) tablet formulation was developed by a domestic pharmaceutical company in Korea. OBJECTIVE: The aim of this clinical study was to evaluate the pharmacokinetic characteristics of PDT in healthy volunteers. METHODS: This study consisted of two clinical trials. In the part 1 study, a randomized, singledose, parallel study was performed with 24 healthy volunteers. All of the subjects were administered one of the three study formulations, Thioctacid® HR (High Release) as the reference, PDT-1 or PDT-2 (each containing thioctic acid 600 mg), respectively. To determine the harmacokinetic characteristics, blood samples were serially collected at pre-dose and at pre-defined timepoints after dosing. In the part 2 study, a randomized, single-dose, two-way crossover study was conducted with 48 subjects. All of the subjects were administered both the reference and PDT-2 formulations, with a 7-day washout period between the two medications. Blood samples were collected at the same timepoints as in the part 1 study. Tolerability was evaluated throughout the study. RESULTS: 23 volunteers completed the part 1 study. The maximum plasma concentration (Cmax) of thioctic acid after administration of the reference tablet was 4.08 ± 2.35 µg/mL (means ± SD), and the Cmax of PDT-1 and PDT-2 was 3.53 ± 2.87 µg/mL and 4.15 ± 1.62 µg/mL, respectively. The AUClast value was 2.96 ± 1.13 µg x h/mL for the reference, 2.84 ± 1.12 µg x h/mL for PDT-1, and 3.30 ± 1.32 µg x h/mL for PDT-2. 42 volunteers completed the part 2 study. The Cmax of reference and PDT-2 was 5.59 ± 3.07 µg/mL and 5.14 ± 3.18 µg/mL, respectively. The AUClast value was 4.01 ± 1.65 µg x h/mL for the reference and 3.96 ± 1.47 µg x h/mL for PDT-2. The geometric mean ratios (PDT-2/reference) and the 90% CI for Cmax and AUClast were 0.93 (0.78 - 1.11) and 1.01 (0.94 - 1.09), respectively. CONCLUSION: Both studies suggested that the pharmacokinetic profile of the newly developed piperazine dithioctate formulation was comparable to the pharmacokinetic profile of the reference tablet. Both study tablets were well tolerated in all of the subjects.

Genetic diversity and structure of the 4th cycle breeding population of Chinese fir (Cunninghamia lanceolata (lamb.) hook).

Studying population genetic structure and diversity is crucial for the marker-assisted selection and breeding of coniferous tree species. In this study, using RAD-seq technology, we developed 343,644 high-quality single nucleotide polymorphism (SNP) markers to resolve the genetic diversity and population genetic structure of 233 Chinese fir selected individuals from the 4th cycle breeding program, representing different breeding generations and provenances. The genetic diversity of the 4th cycle breeding population was high with nucleotide diversity (Pi ) of 0.003, and Ho and He of 0.215 and 0.233, respectively, indicating that the breeding population has a broad genetic base. The genetic differentiation level between the different breeding generations and different provenances was low (Fst < 0.05), with population structure analysis results dividing the 233 individuals into four subgroups. Each subgroup has a mixed branch with interpenetration and weak population structure, which might be related to breeding rather than provenance, with aggregation from the same source only being in the local branches. Our results provide a reference for further research on the marker-assisted selective breeding of Chinese fir and other coniferous trees.

Transcriptome analysis of gibberellins and abscisic acid during the flooding response in Fokienia hodginsii.

Flooding is one of the main abiotic stresses suffered by plants. Plants respond to flooding stress through regulating their morphological structure, endogenous hormone biosynthesis, and genetic signaling transduction. We previously found that Fokienia hodginsii varieties originating from Gutian exhibited typical flooding tolerance traits compared to three other provenances (Yongzhou, Sanming, Nanping), expressed as increased height, longer diameter at breast height (DBH), and smaller branch angle. Herein, the changes in endogenous gibberellins (GA) and abscisic acid (ABA) contents were measured under flooding stress in F. hodginsii, and ABA was found to decrease, whereas GA increased with time. Furthermore, the GA and ABA contents of the varieties originating from Gutian and the three other provenances were measured, and the results indicated that F. hodginsii from Gutian could respond more rapidly to flooding stress. The transcriptomes of the varieties originating from Gutian and the other three provenances were compared using RNA sequencing to explore the underlying genetic mechanisms of the flood-resistant phenotypes in F. hodginsii. The results indicated that two flood-stress response genes (TRINITY_DN142_c0_g2 and TRINITY_DN7657_c0_g1) were highly related to both the ABA and GA response in F. hodginsii.

Exploring the Cunninghamia lanceolata(Lamb.) Hook Genome by BAC Sequencing.

Cunninghamia lanceolata (Lamb.)Hook is an important economic timber tree in China. However, its genome characteristics have not been extensively assessed. To better understand its genome information, the bacterial artificial chromosome (BAC) library of chinese fir was constructed. A total of 422 BAC clones were selected and divided into 10 pools and sequenced, and with an average insert size of 121 kb, ranging from 97 to 145 kb. A total of 61,902,523 bp of reference sequences were sequenced and assembled, and based on an estimated genome size of 11.6 Gb for Chinese fir, the BAC library was estimated to have a total coverage of 0.53% genome equivalents. Bioinformatics analyses were also performed for repeated sequences, tRNAs, coding gene prediction, and functional annotation. The results of this study provide insights into the brief structure of the Chinese fir genome and has generated gene data that will facilitate molecular investigations on the mechanisms underlying tree growth.

Proteome profiling of early seed development in Cunninghamia lanceolata (Lamb.) Hook.

Knowledge of the proteome of the early gymnosperm embryo could provide important information for optimizing plant cloning procedures and for establishing platforms for research into plant development/regulation and in vitro transgenic studies. Compared with angiosperms, it is more difficult to induce somatic embryogenesis in gymnosperms; success in this endeavour could be increased, however, if proteomic information was available on the complex, dynamic, and multistage processes of gymnosperm embryogenesis in vivo. A proteomic analysis of Chinese fir seeds in six developmental stages was carried out during early embryogenesis. Proteins were extracted from seeds dissected from immature cones and separated by two-dimensional difference gel electrophoresis. Analysis with DeCyder 6.5 software revealed 136 spots that differed in kinetics of appearance. Analysis by liquid chromatography coupled to tandem mass spectrometry and MALDI-TOF mass spectrometry identified proteins represented by 71 of the spots. Functional annotation of these seed proteins revealed their involvement in programmed cell death and chromatin modification, indicating that the proteins may play a central role in determining the number of zygotic embryos generated and controlling embryo patterning and shape remodelling. The analysis also revealed other proteins involved in carbon metabolism, methionine metabolism, energy production, protein storage, synthesis and stabilization, disease/defence, the cytoskeleton, and embryo development. The comprehensive protein expression profiles generated by our study provide new insights into the complex developmental processes in the seeds of the Chinese fir.

Preparation of sub-microspherical Fe3O4@PDA-Pd NPs catalyst and application in catalytic hydroreduction reaction of halogenated aromatic nitro compounds to prepare halogenated aromatic amines.

BACKGROUND: The side reactions of dehalogenation or C-N coupling tend to occur when halogenated aromatic amines are prepared by catalytic hydrogenation reduction of halogenated aromatic nitro compounds. In this paper, we prepared the sub-microspherical Fe3O4@PDA-Pd NPs catalyst apply it efficiently in the hydrogenation reduction of halogenated aromatic nitro compounds to prepare the halogenated aromatic amines under atmospheric pressure. The catalyst shows a high selectivity of greater than 96% and can effectively inhibit the occurrence of the side reactions of dehalogenation and C-N coupling. RESULTS: The optimum condition of the hydroreduction reaction is when tetrahydrofuran is used as solvent and the reaction happens at 50 °C for 5 h. The selectivity of the chlorinated aromatic amine and the fluorinated aromatic amine products exceed 99% and the yield exceeds 90%. Only a small amount of dehalogenated products and C-N coupling by-products were produced in the brominated aromatic compound and the iodinated aromatic compound. CONCLUSION: We developed a promising method for preparing the superparamagnetic and strongly magnetic Fe3O4@PDA core-shell sub-microsphere-supported nano-palladium catalyst for catalyzing the hydrogenation reduction of halogenated aromatic nitro compounds. The halogenated aromatic amines were efficiently and highly selectively prepared under atmospheric pressure, with the side reactions of dehalogenation and C-N coupling effectively inhabited simultaneously.