采用美国F inn igan公司GC 2000/T race M S P lus型GC-M S联用仪,对安徽黄山产山苍子香精油进行了组分分析。共分离出63个峰,鉴定出46个化学单体组分,占组分总量95.98%,其中含α-柠檬醛36.82%,β-柠檬醛31.33%,柠檬烯11.59%,甲基庚烯酮...采用美国F inn igan公司GC 2000/T race M S P lus型GC-M S联用仪,对安徽黄山产山苍子香精油进行了组分分析。共分离出63个峰,鉴定出46个化学单体组分,占组分总量95.98%,其中含α-柠檬醛36.82%,β-柠檬醛31.33%,柠檬烯11.59%,甲基庚烯酮2.56%,α-蒎烯1.73%,芳樟醇1.72%,β-蒎烯1.36%,莰烯1.05%等单萜烯或倍半萜烯。并与广西、湖南、贵州产山苍子油化学组分进行比较,发现被鉴定出组分种类数有明显差异,柠檬醛和柠檬烯的含量也不同。这种组分种类及含量的差异与品种、地理条件以及测定仪器有关。展开更多
Diderm bacteria,characterized by an additional lipid membrane layer known as the outer membrane,fold their outer membrane proteins(OMPs)via theβ-barrel assembly machinery(BAM)complex.Understanding how the BAM complex...Diderm bacteria,characterized by an additional lipid membrane layer known as the outer membrane,fold their outer membrane proteins(OMPs)via theβ-barrel assembly machinery(BAM)complex.Understanding how the BAM complex,particularly its key component BamA,assists in OMP folding remains crucial in bacterial cell biology.Recent research has focused primarily on the structural and functional characteristics of BamA within the Gracilicutes clade,such as in Escherichia coli(E.coli).However,another major evolutionary branch,Terrabacteria,has received comparatively less attention.An example of a Terrabacteria is Deinococcus radiodurans(D.radiodurans),a Gram-positive bacterium that possesses a distinctive outer membrane structure.In this study,we first demonstrated that theβ-barrel domains of BamA are not interchangeable between D.radiodurans and E.coli.The structure of D.radiodurans BamA was subsequently determined at 3.8Åresolution using cryo-electron microscopy,revealing obviously distinct arrangements of extracellular loop 4(ECL4)and ECL6 after structural comparison with their counterparts in gracilicutes.Despite the overall similarity in the topology of theβ-barrel domain,our results indicate that certain ECLs have evolved into distinct structures between the Terrabacteria and Gracilicutes clades.While BamA and its function are generally conserved across diderm bacterial species,our findings underscore the evolutionary diversity of this core OMP folder among bacteria,offering new insights into bacterial physiology and evolutionary biology.展开更多
文摘采用美国F inn igan公司GC 2000/T race M S P lus型GC-M S联用仪,对安徽黄山产山苍子香精油进行了组分分析。共分离出63个峰,鉴定出46个化学单体组分,占组分总量95.98%,其中含α-柠檬醛36.82%,β-柠檬醛31.33%,柠檬烯11.59%,甲基庚烯酮2.56%,α-蒎烯1.73%,芳樟醇1.72%,β-蒎烯1.36%,莰烯1.05%等单萜烯或倍半萜烯。并与广西、湖南、贵州产山苍子油化学组分进行比较,发现被鉴定出组分种类数有明显差异,柠檬醛和柠檬烯的含量也不同。这种组分种类及含量的差异与品种、地理条件以及测定仪器有关。
基金supported by the Fundamental Research Funds for the Central Universities(WK9100000063)the Fundamental Research Funds for the Central Universities(WK9100000031)+3 种基金the National Natural Science Foundation of China(32270035,32271241)the Anhui Provincial Natural Science Foundation(2208085MC40,2008085QC98)the Talent Fund Project of Biomedical Sciences and Health Laboratory of Anhui Province,University of Science and Technology of China(BJ9100000003)the start-up funding from the University of Science and Technology of China(KY9100000034,KJ2070000082).
文摘Diderm bacteria,characterized by an additional lipid membrane layer known as the outer membrane,fold their outer membrane proteins(OMPs)via theβ-barrel assembly machinery(BAM)complex.Understanding how the BAM complex,particularly its key component BamA,assists in OMP folding remains crucial in bacterial cell biology.Recent research has focused primarily on the structural and functional characteristics of BamA within the Gracilicutes clade,such as in Escherichia coli(E.coli).However,another major evolutionary branch,Terrabacteria,has received comparatively less attention.An example of a Terrabacteria is Deinococcus radiodurans(D.radiodurans),a Gram-positive bacterium that possesses a distinctive outer membrane structure.In this study,we first demonstrated that theβ-barrel domains of BamA are not interchangeable between D.radiodurans and E.coli.The structure of D.radiodurans BamA was subsequently determined at 3.8Åresolution using cryo-electron microscopy,revealing obviously distinct arrangements of extracellular loop 4(ECL4)and ECL6 after structural comparison with their counterparts in gracilicutes.Despite the overall similarity in the topology of theβ-barrel domain,our results indicate that certain ECLs have evolved into distinct structures between the Terrabacteria and Gracilicutes clades.While BamA and its function are generally conserved across diderm bacterial species,our findings underscore the evolutionary diversity of this core OMP folder among bacteria,offering new insights into bacterial physiology and evolutionary biology.
