琥珀中的甾萜化合物是高等植物分泌的次生代谢物^([1])。因不同植物分泌出的次生代谢物不同,这些丰富的甾萜化合物可作为解译琥珀古植物来源的化学指纹^([2])。但是,现有关于琥珀或树脂化石的化学分类难以区分出琥珀古植物来源的种属,...琥珀中的甾萜化合物是高等植物分泌的次生代谢物^([1])。因不同植物分泌出的次生代谢物不同,这些丰富的甾萜化合物可作为解译琥珀古植物来源的化学指纹^([2])。但是,现有关于琥珀或树脂化石的化学分类难以区分出琥珀古植物来源的种属,甚至较为粗略层次的分类指标(如生物分类系统中的门、科等)都未见系统研究^([3-6])。本研究借用了生物化学领域中常用的比较代谢组学研究思路^([7-8]),以顶空固相微萃取与全二维气相色谱-飞行时间质谱联用为技术手段,系统分析了来自古裸子植物(始新世柏科、白垩纪南洋杉科)和古被子植物(中新世龙脑香料、中新世豆科植物)琥珀中的甾萜化合物^([9]),鉴定的次生代谢物包括83种单萜、186种倍半萜、84种二萜和43种正构烷烃。通过保留指数校正及与国际标准NIST质谱数据库比对,明确了其中大部分次生代谢物的结构及其化学名称。在化学分类前,我们先测试了样品的镜质体反射率和最大热解峰温(T_(max)),证明本文选取的四类琥珀样品具有非常相似的热成熟度;再利用多元统计法从鉴定的396种甾萜化合物中提取出了四条琥珀古植物来源分类标准:(1)根据单萜和二萜的相对含量可区分裸子植物琥珀和被子植物琥珀;(2)10种化学分类标志物可用于区分出两种裸子植物琥珀,包括柏科和南洋杉科;(3)被子植物琥珀中,豆科琥珀和龙脑香料的化学超类存在差异,豆科琥珀的主要成分是倍半萜和二萜,而龙脑香料的主要成分是单萜和倍半萜;(4)其它特殊的化学成分可将豆科琥珀的古植物源鉴定到属级别(Hymenaea mexicana and Hymenaea protera)。由于古植物次生代谢物成分是由植物的基因组控制,本文揭示的化学分类标志具备遗传基础[10-12],研究结果全面建立了古树脂植物次生代谢物数据库,为古植物及古环境研究提供数据基础。展开更多
Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 ...Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.展开更多
文摘琥珀中的甾萜化合物是高等植物分泌的次生代谢物^([1])。因不同植物分泌出的次生代谢物不同,这些丰富的甾萜化合物可作为解译琥珀古植物来源的化学指纹^([2])。但是,现有关于琥珀或树脂化石的化学分类难以区分出琥珀古植物来源的种属,甚至较为粗略层次的分类指标(如生物分类系统中的门、科等)都未见系统研究^([3-6])。本研究借用了生物化学领域中常用的比较代谢组学研究思路^([7-8]),以顶空固相微萃取与全二维气相色谱-飞行时间质谱联用为技术手段,系统分析了来自古裸子植物(始新世柏科、白垩纪南洋杉科)和古被子植物(中新世龙脑香料、中新世豆科植物)琥珀中的甾萜化合物^([9]),鉴定的次生代谢物包括83种单萜、186种倍半萜、84种二萜和43种正构烷烃。通过保留指数校正及与国际标准NIST质谱数据库比对,明确了其中大部分次生代谢物的结构及其化学名称。在化学分类前,我们先测试了样品的镜质体反射率和最大热解峰温(T_(max)),证明本文选取的四类琥珀样品具有非常相似的热成熟度;再利用多元统计法从鉴定的396种甾萜化合物中提取出了四条琥珀古植物来源分类标准:(1)根据单萜和二萜的相对含量可区分裸子植物琥珀和被子植物琥珀;(2)10种化学分类标志物可用于区分出两种裸子植物琥珀,包括柏科和南洋杉科;(3)被子植物琥珀中,豆科琥珀和龙脑香料的化学超类存在差异,豆科琥珀的主要成分是倍半萜和二萜,而龙脑香料的主要成分是单萜和倍半萜;(4)其它特殊的化学成分可将豆科琥珀的古植物源鉴定到属级别(Hymenaea mexicana and Hymenaea protera)。由于古植物次生代谢物成分是由植物的基因组控制,本文揭示的化学分类标志具备遗传基础[10-12],研究结果全面建立了古树脂植物次生代谢物数据库,为古植物及古环境研究提供数据基础。
基金supported by the National Natural Science Foundation of China(No.22090050,No.22090052,No.22176180)National Basic Research Program of China(No.2021YFA1200400)+1 种基金the Natural Science Foundation of Hubei Province(No.2024AFA001)Shenzhen Science and Technology Program(No.JCYJ20220530162406014)。
文摘Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.
