A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1α, 6α, 7β-triacetoxycass-1...A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1α, 6α, 7β-triacetoxycass-13（15）-en-16, 12-olide.展开更多
One new sesquiterpene lactone,1 α,8 α,9 α-trihydroxyeudesman-3（4）,7（11）-dien-8 β,12-olide（1） and two new phenylpropanoidsubstituted catechin glycosides,glabraoside C（2） and glabraoside D（3） were isolated...One new sesquiterpene lactone,1 α,8 α,9 α-trihydroxyeudesman-3（4）,7（11）-dien-8 β,12-olide（1） and two new phenylpropanoidsubstituted catechin glycosides,glabraoside C（2） and glabraoside D（3） were isolated from the whole plant of Sarcandra glabra. Their structures were established by the analyses of spectral and chemical evidences.展开更多
A new sesquiterpene lactone eupatoranolide was isolated from the flowers of Eupatorium adenophorum, its structure was elucidated as 2 beta-acetoxy-(7 alpha, 9 beta H)-3.6(11)-cadinadien-12(7)-olide by spectral analysis.
A new germacranolide sesquiterpene lactone, isoscabertopin, was isolated from Elephantopus scaber together with the known scabertopin. Their structures were determined by spectroscopic methods.
Pseudomonas aeruginosa is a ubiquitous and metabolically versatile microorganism naturally found in soil and water.It is also an opportunistic pathogen in plants,insects,animals,and humans.In response to increasing ce...Pseudomonas aeruginosa is a ubiquitous and metabolically versatile microorganism naturally found in soil and water.It is also an opportunistic pathogen in plants,insects,animals,and humans.In response to increasing cell density,P.aeruginosa uses two acylhomoserine lactone(AHL)quorum-sensing(QS)signals(i.e.,N-3-oxo-dodecanoyl homoserine lactone[3-oxo-C12-HSL]and Nbutanoyl-homoserine lactone[C4-HsL]),which regulate the expression of hundreds of genes.However,how the biosynthesis of these two QS signals is coordinated remains unknown.We studied the regulation of these two QS signals in the rhizosphere strain PA1201.PA1201 sequentially produced 3-oxo-C12-HSL and C4-HSL at the early and late growth stages,respectively.The highest 3-oxo-C12-HSL-dependent elastase activity was observed at the early stage,while the highest C4-HSL-dependent rhamnolipid production was observed at the late stage.The atypical regulator RsaL played a pivotal role in coordinating 3-oxo-C12-HSL and C4-HSL biosynthesis and QS-associated virulence.RsaL repressed las/transcription by binding the-10 and-35 boxes of the lasl promoter.In contrast,RsaL activated rhll transcription by binding the region encoding the 5'-untranslated region of the rhll mRNA.Further,RsaL repressed its own expression by binding a nucleotide motif located in the-35 box of the rsaL promoter.Thus,RsaL acts as a molecular switch that coordinates the sequential biosynthesis of AHL QS signals and differential virulence in PA1201.Finally,C4-HSL activation by RsaL was independent of the Las and Pseudomonas quinolone signal(PQS)QS signaling systems.Therefore,we propose a new model of the QS regulatory network in PA1201,in which RsaL represents a superior player acting at the top of the hierarchy.展开更多
The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 ...The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1（1.0065 g/mL）. The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.展开更多
A new sesquiterpene lactone, strychnilactone (1), together with five known sesquiterpenoids, linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneolinderane (6) have been isolated from...A new sesquiterpene lactone, strychnilactone (1), together with five known sesquiterpenoids, linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneolinderane (6) have been isolated from the extracts of Supercritical Fluid Extraction of Lindera strychnifolia. The structure of the new compound was elucidated by means of spectroscopic analysis. And the relative configuration of 1 was assigned on the basis of NOE analysis.展开更多
基金supported by the science and technology grant of Guangxi province(No.0639039)special purpose of basic scientific research operation grant for commonweal academy and institute of central authorities(No.YZ-1-24).
文摘A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1α, 6α, 7β-triacetoxycass-13（15）-en-16, 12-olide.
基金supported by the National Natural Science Foundation of China(Nos.20772157 and 21132009)National Science and Technology Project of China(No.2011ZX09307-002-01)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT1007)
文摘One new sesquiterpene lactone,1 α,8 α,9 α-trihydroxyeudesman-3（4）,7（11）-dien-8 β,12-olide（1） and two new phenylpropanoidsubstituted catechin glycosides,glabraoside C（2） and glabraoside D（3） were isolated from the whole plant of Sarcandra glabra. Their structures were established by the analyses of spectral and chemical evidences.
文摘A new sesquiterpene lactone eupatoranolide was isolated from the flowers of Eupatorium adenophorum, its structure was elucidated as 2 beta-acetoxy-(7 alpha, 9 beta H)-3.6(11)-cadinadien-12(7)-olide by spectral analysis.
文摘A new germacranolide sesquiterpene lactone, isoscabertopin, was isolated from Elephantopus scaber together with the known scabertopin. Their structures were determined by spectroscopic methods.
基金financially supported by grants from the National Key R&D Program of China(2018YFA0901900 to H.Y.W.)the National Natural Science Foundation of China(No.31972231 to H.Y.W)。
文摘Pseudomonas aeruginosa is a ubiquitous and metabolically versatile microorganism naturally found in soil and water.It is also an opportunistic pathogen in plants,insects,animals,and humans.In response to increasing cell density,P.aeruginosa uses two acylhomoserine lactone(AHL)quorum-sensing(QS)signals(i.e.,N-3-oxo-dodecanoyl homoserine lactone[3-oxo-C12-HSL]and Nbutanoyl-homoserine lactone[C4-HsL]),which regulate the expression of hundreds of genes.However,how the biosynthesis of these two QS signals is coordinated remains unknown.We studied the regulation of these two QS signals in the rhizosphere strain PA1201.PA1201 sequentially produced 3-oxo-C12-HSL and C4-HSL at the early and late growth stages,respectively.The highest 3-oxo-C12-HSL-dependent elastase activity was observed at the early stage,while the highest C4-HSL-dependent rhamnolipid production was observed at the late stage.The atypical regulator RsaL played a pivotal role in coordinating 3-oxo-C12-HSL and C4-HSL biosynthesis and QS-associated virulence.RsaL repressed las/transcription by binding the-10 and-35 boxes of the lasl promoter.In contrast,RsaL activated rhll transcription by binding the region encoding the 5'-untranslated region of the rhll mRNA.Further,RsaL repressed its own expression by binding a nucleotide motif located in the-35 box of the rsaL promoter.Thus,RsaL acts as a molecular switch that coordinates the sequential biosynthesis of AHL QS signals and differential virulence in PA1201.Finally,C4-HSL activation by RsaL was independent of the Las and Pseudomonas quinolone signal(PQS)QS signaling systems.Therefore,we propose a new model of the QS regulatory network in PA1201,in which RsaL represents a superior player acting at the top of the hierarchy.
基金supported by the National Natural Science Found of China (No.51078036)
文摘The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1（1.0065 g/mL）. The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.
文摘A new sesquiterpene lactone, strychnilactone (1), together with five known sesquiterpenoids, linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneolinderane (6) have been isolated from the extracts of Supercritical Fluid Extraction of Lindera strychnifolia. The structure of the new compound was elucidated by means of spectroscopic analysis. And the relative configuration of 1 was assigned on the basis of NOE analysis.
