From the fungus Trichoderma sp., we isolated seven novel 18-residue peptaibols, neoatroviridins E-K ( 1−7 ), and six new 14-residue peptaibols, harzianins NPDG J-O ( 8−13 ). Additionally, four previously characterized...From the fungus Trichoderma sp., we isolated seven novel 18-residue peptaibols, neoatroviridins E-K ( 1−7 ), and six new 14-residue peptaibols, harzianins NPDG J-O ( 8−13 ). Additionally, four previously characterized 18-residue peptaibols neoatroviridins A-D ( 14−17 ) were also identified. The structural configurations of the newly identified peptaibols ( 1−13 ) were determined by comprehensive nuclear magnetic resonance (NMR) and high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) data. Their absolute configurations were further determined using Marfey’s method. Notably, compounds 12 and 13 represent the first 14-residue peptaibols containing an acidic amino acid residue. In antimicrobial assessments, all 18-residue peptaibols ( 1 − 7 , 14 − 17 ) exhibited moderate inhibitory activities against Staphylococcus aureus 209P, with minimum inhibitory concentration (MIC) values ranging from 8−32 μg·mL^(−1). Moreover, compound 9 exhibited moderate inhibitory effect on Candida albicans FIM709, with a MIC value of 16 μg·mL^(−1).展开更多
Allii Macrostemonis Bulbus(Xiebai in Chinese), as a famous traditional Chinese medicine, has great medicinal and dietary values since ancient times. In China, the dry bulbs of Allium macrostemon and Allium chinense ar...Allii Macrostemonis Bulbus(Xiebai in Chinese), as a famous traditional Chinese medicine, has great medicinal and dietary values since ancient times. In China, the dry bulbs of Allium macrostemon and Allium chinense are both used as its original plants. Pharmacological studies have revealed that both of them could increase plasminogen activator activity and prolong the effect of coagulation to achieve antiplatelet aggregation which validates their traditional uses for the treatment of thoracic obstruction and cardialgia in clinics. Besides, several other significant activities, including lipid-lowering, anti-atherosclerosis, antitumor, antispasmodic, antibacterial, antioxidant, and insecticidal activities, have already been reported. The volatile oils, nitrogenous compounds, and steroidal saponins are the major beneficial compounds. Among them, steroidal saponins are considered as the characteristic constituents. In this review, the current information concerning the phytochemistry and pharmacology of Allii Macrostemonis Bulbus is summarized comprehensively. In addition, several research future perspectives are presented, especially the mechanism of bioactive components and fraction from the bulbs of Allium macrostemon and Allium chinense.展开更多
Phytochemical investigation on Forsythia suspensa(Thunb.) Vahl afforded ten compounds, including five lignan glycosides and five phenylethanoid glycosides. The compounds were isolated by using HP-20 macroporous resin,...Phytochemical investigation on Forsythia suspensa(Thunb.) Vahl afforded ten compounds, including five lignan glycosides and five phenylethanoid glycosides. The compounds were isolated by using HP-20 macroporous resin, silica gel, octadecyl silica gel(ODS), size exclusion chromatography resin HW-40 chromatography, and preparative HPLC. The structures were established through application of extensive spectroscopic methods, including ESI-MS, 1D- and 2D-NMR spectroscopy. They were identified as forsythialanside E(1), 8′-hydroxypinoresinol-4′-O-β-D-glucoside(2), 8′-hydroxypinoresinol(3), lariciresinol-4′-O-β- D-glucoside(4), lariciresinol-4-O-β-D-glucoside(5), forsythoside H(6), forsythoside I(7), forsythoside F(8), plantainoside B(9), and plantainoside A(10). Compound 1 was a new lignan glycoside.展开更多
The flower buds of Lonicera macranthoides(Shan Yin-Hua), represent an important traditional Chinese medicine and food ingredient. A phytochemical investigation of the 70% EtOH extract of the flower buds of L. macranth...The flower buds of Lonicera macranthoides(Shan Yin-Hua), represent an important traditional Chinese medicine and food ingredient. A phytochemical investigation of the 70% EtOH extract of the flower buds of L. macranthoides resulted in the isolation of 12 triterpenoids(1-12), including two new ursane-type nortriterpenes, 2α, 24-dihydroxy-23-nor-ursolic acid(1) and 2α, 4α-dihydroxy-23-nor-ursolic acid(2). Their structures were established by multiple spectroscopic methods and comparison with literature data. All isolated compounds were evaluated for their anti-inflammatory effects in LPS-activated RAW264.7 cells. Compounds 1 and 2 exhibited inhibitory effects on iNOS at the concentration of 30 μmol·L^(-1).展开更多
Background Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes （RAG） and RAG-mediated V（D）J recombination. This process is named re...Background Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes （RAG） and RAG-mediated V（D）J recombination. This process is named receptor revision and has been observed in mature peripheral T cells from transgenic mice and human donors. However, whether the receptor revision in mature T cells is a random or orientated process remains poorly understood. Here we used the Jurkat human T cell line, which represents a mature stage of T cell development, as a model to investigate the regulation of T cell receptor （TCR） gene recombination. Methods TCR Dβ-Jβ signal joint T cell receptor excision DNA circles （sjTRECs） were determined by nested and seminested PCR. Double-strand DNA breaks at recombination signal sequences （RSSs） in the TCRVβ chain locus were detected by ligation-mediated-PCR. Further analysis of the complementarity-determining region 3 （CDR3） size of the TCRVβ chain was examined by the TCR GeneScan technique. Results RAG1, RAG2, and three crucial components of the nonhomologous DNA end-joining （NHEJ） pathway were readily detected in Jurkat. Characteristics of junctional diversity of Dβ2-Jβ2 signal joints and ds RSS breaks associated with the Dβ2 5＇ and Dβ 2 3＇ sites were detected in DNA from Jurkat cells. CDR3 size and the gene sequences of the TCRVβ chain did not change during cell proliferation. Conclusions RAG1 and RAG2 and ongoing TCR gene recombination are coexpressed in Jurkat cells, but the ongoing recombination process may not play a role in modification of the TCR repertoire.However, the results suggest that Jurkat could be used as a model for studying the regulation of RAGs and V（D）J recombination and as a ＂special＂ model of the coexistence of TCR gene rearrangements and ＂negative＂ receptor revision.展开更多
基金supported by the National Key Research and Development Program of China(No.2018YFA0903200//2018YFA0903201)the National Natural Science Foundation of China(Nos.81925037 and 81973213)+6 种基金National High-level Personnel of Special Support Program(No.2017RA2259)the 111 Project of Ministry of Education of the People's Republic of China(No.B13038)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Y036)Guangdong International Science and Technology Cooperation Base(No.2021A0505020015)Innovative and Research Teams Project of Guangdong Higher Education Institution(No.2021KCXTD001)K.C.Wong Education Foundation(No.Guo-Dong Chen,2021,China)the Science and Technology Planning Project of Guangzhou(No.202201020048)。
文摘From the fungus Trichoderma sp., we isolated seven novel 18-residue peptaibols, neoatroviridins E-K ( 1−7 ), and six new 14-residue peptaibols, harzianins NPDG J-O ( 8−13 ). Additionally, four previously characterized 18-residue peptaibols neoatroviridins A-D ( 14−17 ) were also identified. The structural configurations of the newly identified peptaibols ( 1−13 ) were determined by comprehensive nuclear magnetic resonance (NMR) and high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) data. Their absolute configurations were further determined using Marfey’s method. Notably, compounds 12 and 13 represent the first 14-residue peptaibols containing an acidic amino acid residue. In antimicrobial assessments, all 18-residue peptaibols ( 1 − 7 , 14 − 17 ) exhibited moderate inhibitory activities against Staphylococcus aureus 209P, with minimum inhibitory concentration (MIC) values ranging from 8−32 μg·mL^(−1). Moreover, compound 9 exhibited moderate inhibitory effect on Candida albicans FIM709, with a MIC value of 16 μg·mL^(−1).
基金financially supported by the Macao Science and Technology Development Fund(No.035/2014/A1)
文摘Allii Macrostemonis Bulbus(Xiebai in Chinese), as a famous traditional Chinese medicine, has great medicinal and dietary values since ancient times. In China, the dry bulbs of Allium macrostemon and Allium chinense are both used as its original plants. Pharmacological studies have revealed that both of them could increase plasminogen activator activity and prolong the effect of coagulation to achieve antiplatelet aggregation which validates their traditional uses for the treatment of thoracic obstruction and cardialgia in clinics. Besides, several other significant activities, including lipid-lowering, anti-atherosclerosis, antitumor, antispasmodic, antibacterial, antioxidant, and insecticidal activities, have already been reported. The volatile oils, nitrogenous compounds, and steroidal saponins are the major beneficial compounds. Among them, steroidal saponins are considered as the characteristic constituents. In this review, the current information concerning the phytochemistry and pharmacology of Allii Macrostemonis Bulbus is summarized comprehensively. In addition, several research future perspectives are presented, especially the mechanism of bioactive components and fraction from the bulbs of Allium macrostemon and Allium chinense.
文摘Phytochemical investigation on Forsythia suspensa(Thunb.) Vahl afforded ten compounds, including five lignan glycosides and five phenylethanoid glycosides. The compounds were isolated by using HP-20 macroporous resin, silica gel, octadecyl silica gel(ODS), size exclusion chromatography resin HW-40 chromatography, and preparative HPLC. The structures were established through application of extensive spectroscopic methods, including ESI-MS, 1D- and 2D-NMR spectroscopy. They were identified as forsythialanside E(1), 8′-hydroxypinoresinol-4′-O-β-D-glucoside(2), 8′-hydroxypinoresinol(3), lariciresinol-4′-O-β- D-glucoside(4), lariciresinol-4-O-β-D-glucoside(5), forsythoside H(6), forsythoside I(7), forsythoside F(8), plantainoside B(9), and plantainoside A(10). Compound 1 was a new lignan glycoside.
基金supported by the National Natural Science Foundation of China(Nos.81602984 and 81630097)Science and Technology Planning Project of Guangdong Province(No.2015B030301005)
文摘The flower buds of Lonicera macranthoides(Shan Yin-Hua), represent an important traditional Chinese medicine and food ingredient. A phytochemical investigation of the 70% EtOH extract of the flower buds of L. macranthoides resulted in the isolation of 12 triterpenoids(1-12), including two new ursane-type nortriterpenes, 2α, 24-dihydroxy-23-nor-ursolic acid(1) and 2α, 4α-dihydroxy-23-nor-ursolic acid(2). Their structures were established by multiple spectroscopic methods and comparison with literature data. All isolated compounds were evaluated for their anti-inflammatory effects in LPS-activated RAW264.7 cells. Compounds 1 and 2 exhibited inhibitory effects on iNOS at the concentration of 30 μmol·L^(-1).
基金grants from Major State Basic Research Development 973 Program of China(No.2001CB510008 and 2003CB514113)NSFC & Research Grant Coancil of Hong Kong Joint Research Fund(No.30418003).
文摘Background Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes （RAG） and RAG-mediated V（D）J recombination. This process is named receptor revision and has been observed in mature peripheral T cells from transgenic mice and human donors. However, whether the receptor revision in mature T cells is a random or orientated process remains poorly understood. Here we used the Jurkat human T cell line, which represents a mature stage of T cell development, as a model to investigate the regulation of T cell receptor （TCR） gene recombination. Methods TCR Dβ-Jβ signal joint T cell receptor excision DNA circles （sjTRECs） were determined by nested and seminested PCR. Double-strand DNA breaks at recombination signal sequences （RSSs） in the TCRVβ chain locus were detected by ligation-mediated-PCR. Further analysis of the complementarity-determining region 3 （CDR3） size of the TCRVβ chain was examined by the TCR GeneScan technique. Results RAG1, RAG2, and three crucial components of the nonhomologous DNA end-joining （NHEJ） pathway were readily detected in Jurkat. Characteristics of junctional diversity of Dβ2-Jβ2 signal joints and ds RSS breaks associated with the Dβ2 5＇ and Dβ 2 3＇ sites were detected in DNA from Jurkat cells. CDR3 size and the gene sequences of the TCRVβ chain did not change during cell proliferation. Conclusions RAG1 and RAG2 and ongoing TCR gene recombination are coexpressed in Jurkat cells, but the ongoing recombination process may not play a role in modification of the TCR repertoire.However, the results suggest that Jurkat could be used as a model for studying the regulation of RAGs and V（D）J recombination and as a ＂special＂ model of the coexistence of TCR gene rearrangements and ＂negative＂ receptor revision.
