Six new indole alkaloid sulfonic acids(1–6), together with two analogues(7 and 8) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their struct...Six new indole alkaloid sulfonic acids(1–6), together with two analogues(7 and 8) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95(H3N2), respectively.展开更多
Phenylpropanoid derivatives are a complex class of secondary metabolites that have many important roles in plants during normal growth and in responses to environmental stress. Phenylalanine ammonialyase （PAL） catal...Phenylpropanoid derivatives are a complex class of secondary metabolites that have many important roles in plants during normal growth and in responses to environmental stress. Phenylalanine ammonialyase （PAL） catalyzes the first step in the biosynthesis of phenylpropanoids. In the present study, we isolated a novel phenylalanine ammonialyase gene （designated as liPAL） from tetraploid Isatis indigotica Fort. by rapid amplification of cDNA ends （RACE）, which was a cultivar from the diploid plant by genome duplication. The full-length cDNA of liPAL was 2 530-bp long with an open reading frame （ORF） of 2 178 bp encoding a polypeptide of 725 amino acid residues. Analysis of liPAL genomic DNA revealed that it was structurally similar to other plant PAL genes, with a single intron at a conserved position, and a long highly conserved second exon. Semi-quantitative RT-PCR revealed that the liPAL expression in roots and leaves from a tetraploid sample was higher than that in diploid progenitor, whereas expression of liPAL in stems was almost the same as each other. Furthermore, the highest expression of liPAL in tetraploid plant was found in roots, which was found in stems in diploid plants. Further expression analysis revealed that gibberelUn （GA3）, abscisic acid （ABA）, methyl jasmonate （MeJA） and cold treatments could up-regulate the liPAL transcription in tetraploid plants. All our findings suggest that liPAL participates not only in the defense/stress responsive pathways, but also probably in the polyploidy evolution of L indigotica.展开更多
Three pairs of glycosidic 8,4′-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F(1–6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations wer...Three pairs of glycosidic 8,4′-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F(1–6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations were elucidated by comprehensive spectroscopic data analysis and enzyme hydrolysis. The validity of Δδ_(C8-C7) values to distinguish threo and erythro aryl glycerol units and Cotton effects at 235±5 nm to determine absolute configurations at C-8 in 1–6 and their aglycones(1a–6a) are discussed.展开更多
基金Financial support from the National Natural Sciences Foundation of China(NNSFCgrant Nos.81373287,81630094 and 30825044)is acknowledged
文摘Six new indole alkaloid sulfonic acids(1–6), together with two analogues(7 and 8) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95(H3N2), respectively.
基金Supported by the National Natural Science Foundation of China （30371746）,
文摘Phenylpropanoid derivatives are a complex class of secondary metabolites that have many important roles in plants during normal growth and in responses to environmental stress. Phenylalanine ammonialyase （PAL） catalyzes the first step in the biosynthesis of phenylpropanoids. In the present study, we isolated a novel phenylalanine ammonialyase gene （designated as liPAL） from tetraploid Isatis indigotica Fort. by rapid amplification of cDNA ends （RACE）, which was a cultivar from the diploid plant by genome duplication. The full-length cDNA of liPAL was 2 530-bp long with an open reading frame （ORF） of 2 178 bp encoding a polypeptide of 725 amino acid residues. Analysis of liPAL genomic DNA revealed that it was structurally similar to other plant PAL genes, with a single intron at a conserved position, and a long highly conserved second exon. Semi-quantitative RT-PCR revealed that the liPAL expression in roots and leaves from a tetraploid sample was higher than that in diploid progenitor, whereas expression of liPAL in stems was almost the same as each other. Furthermore, the highest expression of liPAL in tetraploid plant was found in roots, which was found in stems in diploid plants. Further expression analysis revealed that gibberelUn （GA3）, abscisic acid （ABA）, methyl jasmonate （MeJA） and cold treatments could up-regulate the liPAL transcription in tetraploid plants. All our findings suggest that liPAL participates not only in the defense/stress responsive pathways, but also probably in the polyploidy evolution of L indigotica.
基金Financial support from the National Natural Sciences Foundation of China(NNSFCGrant Nos.81373287,81630094,and 30825044)
文摘Three pairs of glycosidic 8,4′-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F(1–6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations were elucidated by comprehensive spectroscopic data analysis and enzyme hydrolysis. The validity of Δδ_(C8-C7) values to distinguish threo and erythro aryl glycerol units and Cotton effects at 235±5 nm to determine absolute configurations at C-8 in 1–6 and their aglycones(1a–6a) are discussed.
