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1.
Chem Commun (Camb) ; 59(46): 7108-7111, 2023 Jun 06.
Article in English | MEDLINE | ID: mdl-37218633

ABSTRACT

Alkyl boronic acid and its derivatives are important motifs in organic synthesis and pharmaceuticals. Herein, we report a photoinduced, CuCl2 mediated C(sp3)-H borylation of unactivated alkanes. This protocol features mild reaction conditions, readily available reagents, and gram-scalability.

2.
J Org Chem ; 86(22): 16114-16120, 2021 11 19.
Article in English | MEDLINE | ID: mdl-33416327

ABSTRACT

We developed an electrochemical trifluoromethylation of thiophenols without the use of metal catalysts and oxidants. This reaction features mild reaction conditions, readily available substrate, as well as moderate to good yields. In addition, this protocol can be easily scaled up with moderate efficiency.


Subject(s)
Hydrocarbons, Fluorinated , Mesylates , Phenols , Sulfhydryl Compounds
3.
J Agric Food Chem ; 66(30): 8069-8078, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-30001627

ABSTRACT

Transcription factors that include myeloblastosis (MYB), basic helix-loop-helix (bHLH), and tryptophan-aspartic acid (WD)-repeat protein often form a ternary complex to regulate the phenylpropanoid pathway. However, only a few MYB and bHLH members involved in the biosynthesis of salvianolic acid B (Sal B) have been reported, and little is known about Sal B pathway regulation by the WD40 protein transparent testa glabra 1 (TTG1)-dependent transcriptional complexes in Salvia miltiorrhiza. We isolated SmTTG1 from that species for detailed functional characterization. Enhanced or reduced expression of SmTTG1 was achieved by gain- or loss-of-function assays, respectively, revealing that SmTTG1 is necessary for Sal B biosynthesis. Interaction partners of the SmTTG1 protein were screened by yeast two-hybrid (Y2H) assays with the cDNA library of S. miltiorrhiza. A new R2R3-MYB transcription factor, SmMYB111, was found through this screening. Transgenic plants overexpressing or showing reduced expression of SmMYB111 upregulated or deregulated, respectively, the yields of Sal B. Both Y2H and bimolecular fluorescent complementation experiments demonstrated that SmMYB111 interacts with SmTTG1 and SmbHLH51, a positive regulator of the phenolic acid pathway. Our data verified the function of SmTTG1 and SmMYB111 in regulating phenolic acid biosynthesis in S. miltiorrhiza. Furthermore, ours is the first report of the potential ternary transcription complex SmTTG1-SmMYB111-SmbHLH51, which is involved in the production of Sal B in that species.


Subject(s)
Hydroxybenzoates/metabolism , Plant Proteins/metabolism , Salvia miltiorrhiza/metabolism , Transcription Factors/metabolism , Gene Expression Regulation, Plant , Helix-Turn-Helix Motifs , Plant Proteins/chemistry , Plant Proteins/genetics , Protein Binding , Salvia miltiorrhiza/chemistry , Salvia miltiorrhiza/genetics , Transcription Factors/chemistry , Transcription Factors/genetics
4.
Protoplasma ; 254(2): 685-696, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27193100

ABSTRACT

Abiotic stresses, such as drought and high salinity, are major factors that limit plant growth and productivity. Late embryogenesis abundant (LEA) proteins are members of a diverse, multigene family closely associated with tolerance to abiotic stresses in numerous organisms. We examined the function of SmLEA2, previously isolated from Salvia miltiorrhiza, in defense responses to drought and high salinity. Phylogenetic analysis indicated that SmLEA2 belongs to the LEA_2 subfamily. Its overexpression in Escherichia coli improved growth performance when compared with the control under salt and drought stresses. We further characterized its roles in S. miltiorrhiza through overexpression and RNAi-mediated silencing. In response to drought and salinity treatments, transgenic plants overexpressing SmLEA2 exhibited significantly increased superoxide dismutase activity, reduced levels of lipid peroxidation, and more vigorous growth than empty-vector control plants did. However, transgenic lines in which expression was suppressed showed the opposite results. Our data demonstrate that SmLEA2 plays an important role in the abiotic stress response and its overexpression in transgenic S. miltiorrhiza improves tolerance to excess salt and drought conditions.


Subject(s)
Droughts , Escherichia coli/physiology , Genes, Plant , Plant Proteins/genetics , Salvia miltiorrhiza/genetics , Sodium Chloride/pharmacology , Stress, Physiological/drug effects , Adaptation, Physiological/drug effects , Adaptation, Physiological/genetics , Electrophoresis, Polyacrylamide Gel , Escherichia coli/drug effects , Gene Expression Regulation, Plant/drug effects , Microbial Viability/drug effects , Phenotype , Phylogeny , Plant Proteins/isolation & purification , Plant Proteins/metabolism , Plant Transpiration/drug effects , Plants, Genetically Modified , Potassium/metabolism , Salinity , Salvia miltiorrhiza/drug effects , Salvia miltiorrhiza/physiology , Sodium/metabolism , Stress, Physiological/genetics
5.
PLoS One ; 11(11): e0166493, 2016.
Article in English | MEDLINE | ID: mdl-27851826

ABSTRACT

Gentiana macrophylla, a medicinal plant with significant pharmacological properties, contains the bioactive compound gentiopicroside. Methyl jasmonate (MeJA) is an effective elicitor for enhancing the production of such compounds. However, little is known about MeJA-mediated biosynthesis of gentiopicroside. We investigated this phenomenon as well as gene expression profiles to determine the molecular mechanisms for MeJA-mediated gentiopicroside biosynthesis and regulation in G. macrophylla. Our HPLC results showed that Gentiana macrophylla seedlings exposed to MeJA had significantly higher concentrations of gentiopicroside when compared with control plants. We used RNA sequencing to compare transcriptional profiles in seedlings treated for 5 d with either 0 µmol L-1 MeJA (C) or 250 µmol L-1 MeJA (M5) and detected differentially expressed genes (DEGs). In total, 77,482 unique sequences were obtained from approximately 34 million reads. Of these, 48,466 (57.46%) sequences were annotated based on BLASTs performed against public databases. We identified 5,206 DEGs between the C and M5 samples, including genes related to the α-lenolenic acid degradation pathway, JA signaling pathway, and gentiopicroside biosynthesis. Expression of numerous enzyme genes in the glycolysis pathway was significantly up-regulated. Many genes encoding transcription factors (e.g. ERF, bHLH, MYB, and WRKY) also responded to MeJA elicitation. Rapid acceleration of the glycolysis pathway that supplies precursors for IPP biosynthesis and up-regulates the expression of enzyme genes in that IPP pathway are probably most responsible for MeJA stimulation of gentiopicroside synthesis. Our qRT-PCR results showed that the expression profiles of 12 gentiopicroside biosynthesis genes were consistent with the RNA-Seq data. These results increase our understanding about how the gentiopicroside biosynthesis pathway in G. macrophylla responds to MeJA.


Subject(s)
Acetates/pharmacology , Biosynthetic Pathways/genetics , Cyclopentanes/pharmacology , Gentiana/genetics , Iridoid Glucosides/metabolism , Oxylipins/pharmacology , Seedlings/genetics , Transcription, Genetic/drug effects , Biosynthetic Pathways/drug effects , Cyclopentanes/metabolism , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Gentiana/drug effects , Glycolysis/drug effects , Molecular Sequence Annotation , Oxylipins/metabolism , Real-Time Polymerase Chain Reaction , Reproducibility of Results , Secondary Metabolism/drug effects , Secondary Metabolism/genetics , Seedlings/drug effects , Sequence Analysis, RNA , Signal Transduction/drug effects , Signal Transduction/genetics , Transcription Factors/metabolism , Transcriptome , Up-Regulation/drug effects , Up-Regulation/genetics , alpha-Linolenic Acid/metabolism
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