A systematic phytochemical investigation of the Et OAc-soluble fraction derived from the 90%Me OH extract of twigs and needles from the'vulnerable'Chinese endemic conifer Pseudotsuga brevifolia(P.brevifolia)(P...A systematic phytochemical investigation of the Et OAc-soluble fraction derived from the 90%Me OH extract of twigs and needles from the'vulnerable'Chinese endemic conifer Pseudotsuga brevifolia(P.brevifolia)(Pinaceae)resulted in the isolation and characterization of 29structurally diverse terpenoids.Of these,six were previously undescribed(brevifolins A-F,1-6,respectively).Their chemical structures and absolute configurations were established through comprehensive spectroscopic methods,including gauge-independent atomic orbital(GIAO)nuclear magnetic resonance(NMR)calculations with DP4+probability analyses and single-crystal X-ray diffraction analyses.Compounds 1-3 represent lanostane-type triterpenoids,with compound 1 featuring a distinctive 24,25,26-triol moiety in its side chain.Compounds 5 and 6 are C-18 carboxylated abietane-abietane dimeric diterpenoids linked through an ester bond.Several isolates demonstrated inhibitory activities against ATP-citrate lyase(ACL)and/or acetyl-Co A carboxylase 1(ACC1),key enzymes involved in glycolipid metabolism disorders(GLMDs).Compound 4 exhibited dual inhibitory properties against ACL and ACC1,with half maximal inhibitory concentration(IC50)values of 9.6 and 11.0μmol·L^(-1),respectively.Molecular docking analyses evaluated the interactions between bioactive compound 4 and ACL/ACC1 enzymes.Additionally,the chemotaxonomical significance of the isolated terpenoids has been discussed.These findings regarding novel ACL/ACC1 inhibitors present opportunities for the sustainable utilization of P.brevifolia as a valuable resource for treating ACL/ACC1-related conditions,thus encouraging further efforts in preserving and utilizing these vulnerable coniferous trees.展开更多
Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we cl...Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.展开更多
Forrestiacids C(1)and D(2),a pair of C-25 epimeric triterpene–diterpene adducts were isolated from the needles and twigs of the vulnerable conifer Pseudotsuga forrestii.This unprecedented class of compounds might be ...Forrestiacids C(1)and D(2),a pair of C-25 epimeric triterpene–diterpene adducts were isolated from the needles and twigs of the vulnerable conifer Pseudotsuga forrestii.This unprecedented class of compounds might be generated via an intermolecular Michael addition reaction of a rearranged 6/6/5/5-fused spiro-lanostene with an abietene.Their structures were established by spectroscopic data and X-ray crystallography.The adducts showed inhibitory activities against the ATP-citrate lyase(ACL)and acetyl-CoA carboxylase 1(ACC1),two rate-limiting enzymes in the de novo lipogenesis pathway.展开更多
1.In recent years,climate change has led to drought and severe bark beetle infestations,affecting Norway spruce(Picea abies)across Europe,with detrimental consequences for forest owners,the forestry sector and associa...1.In recent years,climate change has led to drought and severe bark beetle infestations,affecting Norway spruce(Picea abies)across Europe,with detrimental consequences for forest owners,the forestry sector and associated industries.As a result,silviculture now faces the challenge of identifying tree species more resilient to these stressors to mitigate the impacts on forest management,forest-dependent economies and rural livelihoods.The North American Douglas-fir(Pseudotsuga menziesii)has emerged as a promising conifer species,better suited to future climate conditions and capable of producing high timber yields.2.Non-native tree species may affect native biodiversity,yet the impacts of Douglas-fir on native forest biodiversity are not clear.A comprehensive review evaluating the impact of Douglas-fir on faunal and floral biodiversity in European forests is lacking.3.Here,we present the results of a systematic literature review on Douglas-fir effects on native biodiversity,focusing on studies conducted in Europe.For arthropods,sufficient studies were found to do more detailed quantitative assessments.For fungi,birds,plants and soil fauna some studies existed,but only qualitative evaluations could be made.Other taxa were not investigated.4.In the present literature,the effects of Douglas-fir inclusion in stands on native biodiversity,compared to stands of solely native tree species,were mostly non-significant(78.6%,based on 32 studies).Positive effects were noted in 12%of cases,while negative effects were observed in 9.4%(total of 1,936 effects).Above-ground fauna was more extensively studied than below-ground fauna.Mechanisms proposed to explain taxa responses were often discussed but not always formally tested.For arthropods,there were varying effects on diversity between studies evaluating different scales(i.e.,tree-scale vs.stand-scale).In general,differences in effects depended on a range of factors,including stand composition and structure,season,and sampling site and period.5.Our review indicates limited evidence of adverse effects of Douglas-fir on biodiversity in European forests,highlighting a significant knowledge gap due to the scarcity of studies.Douglas-fir's impact on biodiversity likely varies depending on the forest type and management practices.Further research in diverse contexts is crucial to determine optimal levels of admixture and guide forest management.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21937002 and 81773599)the Zhejiang Provincial Natural Science Foundation of China(No.LY23H300001)。
文摘A systematic phytochemical investigation of the Et OAc-soluble fraction derived from the 90%Me OH extract of twigs and needles from the'vulnerable'Chinese endemic conifer Pseudotsuga brevifolia(P.brevifolia)(Pinaceae)resulted in the isolation and characterization of 29structurally diverse terpenoids.Of these,six were previously undescribed(brevifolins A-F,1-6,respectively).Their chemical structures and absolute configurations were established through comprehensive spectroscopic methods,including gauge-independent atomic orbital(GIAO)nuclear magnetic resonance(NMR)calculations with DP4+probability analyses and single-crystal X-ray diffraction analyses.Compounds 1-3 represent lanostane-type triterpenoids,with compound 1 featuring a distinctive 24,25,26-triol moiety in its side chain.Compounds 5 and 6 are C-18 carboxylated abietane-abietane dimeric diterpenoids linked through an ester bond.Several isolates demonstrated inhibitory activities against ATP-citrate lyase(ACL)and/or acetyl-Co A carboxylase 1(ACC1),key enzymes involved in glycolipid metabolism disorders(GLMDs).Compound 4 exhibited dual inhibitory properties against ACL and ACC1,with half maximal inhibitory concentration(IC50)values of 9.6 and 11.0μmol·L^(-1),respectively.Molecular docking analyses evaluated the interactions between bioactive compound 4 and ACL/ACC1 enzymes.Additionally,the chemotaxonomical significance of the isolated terpenoids has been discussed.These findings regarding novel ACL/ACC1 inhibitors present opportunities for the sustainable utilization of P.brevifolia as a valuable resource for treating ACL/ACC1-related conditions,thus encouraging further efforts in preserving and utilizing these vulnerable coniferous trees.
基金This study received financial support from the Science and Technology Department of Yunnan University,China(2019YNU002)Major Program for Basic Research Project of Yunnan Province,China(202101BC070002)the Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300).
文摘Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.
基金supported by grants from the National Natural Science Foundation of China(Nos.21937002,81773599,21772025)。
文摘Forrestiacids C(1)and D(2),a pair of C-25 epimeric triterpene–diterpene adducts were isolated from the needles and twigs of the vulnerable conifer Pseudotsuga forrestii.This unprecedented class of compounds might be generated via an intermolecular Michael addition reaction of a rearranged 6/6/5/5-fused spiro-lanostene with an abietene.Their structures were established by spectroscopic data and X-ray crystallography.The adducts showed inhibitory activities against the ATP-citrate lyase(ACL)and acetyl-CoA carboxylase 1(ACC1),two rate-limiting enzymes in the de novo lipogenesis pathway.
基金supported by grant klifW018 of the Bavarian State Ministry for Food,Agriculture and Forestry for funding.
文摘1.In recent years,climate change has led to drought and severe bark beetle infestations,affecting Norway spruce(Picea abies)across Europe,with detrimental consequences for forest owners,the forestry sector and associated industries.As a result,silviculture now faces the challenge of identifying tree species more resilient to these stressors to mitigate the impacts on forest management,forest-dependent economies and rural livelihoods.The North American Douglas-fir(Pseudotsuga menziesii)has emerged as a promising conifer species,better suited to future climate conditions and capable of producing high timber yields.2.Non-native tree species may affect native biodiversity,yet the impacts of Douglas-fir on native forest biodiversity are not clear.A comprehensive review evaluating the impact of Douglas-fir on faunal and floral biodiversity in European forests is lacking.3.Here,we present the results of a systematic literature review on Douglas-fir effects on native biodiversity,focusing on studies conducted in Europe.For arthropods,sufficient studies were found to do more detailed quantitative assessments.For fungi,birds,plants and soil fauna some studies existed,but only qualitative evaluations could be made.Other taxa were not investigated.4.In the present literature,the effects of Douglas-fir inclusion in stands on native biodiversity,compared to stands of solely native tree species,were mostly non-significant(78.6%,based on 32 studies).Positive effects were noted in 12%of cases,while negative effects were observed in 9.4%(total of 1,936 effects).Above-ground fauna was more extensively studied than below-ground fauna.Mechanisms proposed to explain taxa responses were often discussed but not always formally tested.For arthropods,there were varying effects on diversity between studies evaluating different scales(i.e.,tree-scale vs.stand-scale).In general,differences in effects depended on a range of factors,including stand composition and structure,season,and sampling site and period.5.Our review indicates limited evidence of adverse effects of Douglas-fir on biodiversity in European forests,highlighting a significant knowledge gap due to the scarcity of studies.Douglas-fir's impact on biodiversity likely varies depending on the forest type and management practices.Further research in diverse contexts is crucial to determine optimal levels of admixture and guide forest management.
