Kalmane diterpenoids,featuring a 5/8/5/5 tetracyclic carbon skeleton,are very rare in nature.The flowers of Rhododendron dauricum L.(Ericaceae)were phytochemically investigated for the first time,leading to the isolat...Kalmane diterpenoids,featuring a 5/8/5/5 tetracyclic carbon skeleton,are very rare in nature.The flowers of Rhododendron dauricum L.(Ericaceae)were phytochemically investigated for the first time,leading to the isolation of eight kalmane diterpenoids(1-8)including four new ones,named rhodokalmanols A-D(1-4).The structures of 1-8 were elucidated by comprehensive spectroscopic methods and ic NMR-DP4+analysis,and the absolute configurations of 1,2,4,and 5 were defined by single-crystal X-ray diffraction analysis with Cu Kαradiation.Rhodokalmanol A(1)represents the first 5,8-epoxykalmane diterpenoid and also the first kalm-15(16)-ene diterpenoid.Rhodokalmanols BD(2-4)are the first examples of kalm-7(8)-ene,kalm-16(17)-ene,and 8α-methoxykalmane diterpenoids,respectively.All the isolated kalmane diterpenoids 1-8 exhibited significant analgesic effects,and rhodokalmanol C(3)and kalmanoi(8)expressed more potent analgesic activity than morphine at doses of 0.2 and 0.04 mg/kg.The preliminary structure-activity relationships of kalmane diterpenoids as potent analgesics are discussed.展开更多
A novel diterpenoid with an unprecedented 5/6/5/7 tetracyclic system, rhodauricanol A(1), five new grayanane-derived diterpenoids, dauricanols A-E(2-6), and five known ones(7-11) were isolated from the flowers of Rhod...A novel diterpenoid with an unprecedented 5/6/5/7 tetracyclic system, rhodauricanol A(1), five new grayanane-derived diterpenoids, dauricanols A-E(2-6), and five known ones(7-11) were isolated from the flowers of Rhododendron dauricum. Rhodauricanol A(1) possesses a unique 5/6/5/7 tetracyclic ring system featuring a 16-oxa-tetracyclo[11.2.1.0^(1,5).0^(7,13)]hexadecane core. Dauricanols A-C(2-4) are the first1,3-dioxolane conjugates of grayanane diterpenoids and 5-hydroxymethylfurfural and vanillin, respectively, and dauricanols D(5) and E(6) represent the first examples of 6-deoxy-1,5-seco-grayanane diterpenoids. Their structures were determined by spectroscopic methods, quantum chemical calculation including ^(13)C NMR-DP4+ analysis and ECD calculation, and single-crystal X-ray diffraction analysis. Plausible biosynthetic pathways for 1-4 were proposed. All the isolates showed significant analgesic activities,and dauricanols B(3) and C(4) showed more potent analgesic activities than the positive control, morphine.展开更多
The present study was designed to determine the major chemical constituents of the leaves of Rhododendron dauricum L. Compounds were isolated and purified by various chromatographic methods, and their structures were ...The present study was designed to determine the major chemical constituents of the leaves of Rhododendron dauricum L. Compounds were isolated and purified by various chromatographic methods, and their structures were elucidated by physicochemical properties and spectral data. The present study identified two new C-methyl flavanones, 5, 7, 3', 5'-tetrahydroxy-6, 8-di-C-methyl flavanone(1) and 5, 4'-dihydroxy-8-C-methylflavanone-7-O-β-D-glucopyranoside(2), and one new flavonoid glycoside, quercetin-3-O-β-D-(6''-O-cinnamoyl)-galactoside(3), along with seven known compounds, including syzalterin(4), poriolin(5), farrerol-7-O-β-D-glucopyranoside(6), myrciacetin(7), quercetin-3-O-β-D-(6-p-hydroxy-benzoyl)-galactoside(8), quercetin-3-O-β-D-(6-p-coumaroyl)-galactoside(9), and 5, 7, 3', 5'-tetrahydroxyl flavanone(10). Compounds 1-3 were determined to be new flavonoids; compounds 4-6 were isolated from this species for the first time; and compounds 7-10 were reported for the first time from this genus.展开更多
为了了解大兴安岭北部地区兴安杜鹃(Rhododendron dauricum L.)的菌根真菌多样性特征。采用形态学和r DNA ITS序列分析相结合的方法。结果表明从兴安杜鹃根样中分离得到的真菌分属于7个属:Phialocephala、粒毛盘菌属(Lachnum)、膜盘菌属...为了了解大兴安岭北部地区兴安杜鹃(Rhododendron dauricum L.)的菌根真菌多样性特征。采用形态学和r DNA ITS序列分析相结合的方法。结果表明从兴安杜鹃根样中分离得到的真菌分属于7个属:Phialocephala、粒毛盘菌属(Lachnum)、膜盘菌属(Hymenoscyphus)、Meliniomyces、丝核菌属(Rhizoctonia)、被孢霉属(Mortierella)和软盘菌属(Mollisia)。其中Phialocephala、粒毛盘菌属(Lachnum)和膜盘菌属(Hymenoscyphus)为兴安杜鹃菌根真菌优势类群,在分离的菌株中所占比率超过了20%。研究表明与兴安杜鹃根共生的真菌类群较丰富。展开更多
基金This work was financially supported by the Scientific Research Project of Traditional Chinese Medicine of Hubei Provincial Health Commission(ZY2021M056)the Open Project of State Key Laboratory of Chemistry and Molecular Engineering of Medicinal Resources(No.CMEMR-2021-B03)。
文摘Kalmane diterpenoids,featuring a 5/8/5/5 tetracyclic carbon skeleton,are very rare in nature.The flowers of Rhododendron dauricum L.(Ericaceae)were phytochemically investigated for the first time,leading to the isolation of eight kalmane diterpenoids(1-8)including four new ones,named rhodokalmanols A-D(1-4).The structures of 1-8 were elucidated by comprehensive spectroscopic methods and ic NMR-DP4+analysis,and the absolute configurations of 1,2,4,and 5 were defined by single-crystal X-ray diffraction analysis with Cu Kαradiation.Rhodokalmanol A(1)represents the first 5,8-epoxykalmane diterpenoid and also the first kalm-15(16)-ene diterpenoid.Rhodokalmanols BD(2-4)are the first examples of kalm-7(8)-ene,kalm-16(17)-ene,and 8α-methoxykalmane diterpenoids,respectively.All the isolated kalmane diterpenoids 1-8 exhibited significant analgesic effects,and rhodokalmanol C(3)and kalmanoi(8)expressed more potent analgesic activity than morphine at doses of 0.2 and 0.04 mg/kg.The preliminary structure-activity relationships of kalmane diterpenoids as potent analgesics are discussed.
基金supported by the Fund of State Key Laboratory of Phytochemistry and Plant Resources in West China (NoP2022-KF08)National Natural Science Foundation of China (Nos.22107033 and U1703109)the Scientific Research Project of Traditional Chinese Medicine of Hubei Provincial Health Commission (No. ZY2021M056)。
文摘A novel diterpenoid with an unprecedented 5/6/5/7 tetracyclic system, rhodauricanol A(1), five new grayanane-derived diterpenoids, dauricanols A-E(2-6), and five known ones(7-11) were isolated from the flowers of Rhododendron dauricum. Rhodauricanol A(1) possesses a unique 5/6/5/7 tetracyclic ring system featuring a 16-oxa-tetracyclo[11.2.1.0^(1,5).0^(7,13)]hexadecane core. Dauricanols A-C(2-4) are the first1,3-dioxolane conjugates of grayanane diterpenoids and 5-hydroxymethylfurfural and vanillin, respectively, and dauricanols D(5) and E(6) represent the first examples of 6-deoxy-1,5-seco-grayanane diterpenoids. Their structures were determined by spectroscopic methods, quantum chemical calculation including ^(13)C NMR-DP4+ analysis and ECD calculation, and single-crystal X-ray diffraction analysis. Plausible biosynthetic pathways for 1-4 were proposed. All the isolates showed significant analgesic activities,and dauricanols B(3) and C(4) showed more potent analgesic activities than the positive control, morphine.
基金supported by the National Natural Science Foundation of China(No.81373956)
文摘The present study was designed to determine the major chemical constituents of the leaves of Rhododendron dauricum L. Compounds were isolated and purified by various chromatographic methods, and their structures were elucidated by physicochemical properties and spectral data. The present study identified two new C-methyl flavanones, 5, 7, 3', 5'-tetrahydroxy-6, 8-di-C-methyl flavanone(1) and 5, 4'-dihydroxy-8-C-methylflavanone-7-O-β-D-glucopyranoside(2), and one new flavonoid glycoside, quercetin-3-O-β-D-(6''-O-cinnamoyl)-galactoside(3), along with seven known compounds, including syzalterin(4), poriolin(5), farrerol-7-O-β-D-glucopyranoside(6), myrciacetin(7), quercetin-3-O-β-D-(6-p-hydroxy-benzoyl)-galactoside(8), quercetin-3-O-β-D-(6-p-coumaroyl)-galactoside(9), and 5, 7, 3', 5'-tetrahydroxyl flavanone(10). Compounds 1-3 were determined to be new flavonoids; compounds 4-6 were isolated from this species for the first time; and compounds 7-10 were reported for the first time from this genus.
文摘为了了解大兴安岭北部地区兴安杜鹃(Rhododendron dauricum L.)的菌根真菌多样性特征。采用形态学和r DNA ITS序列分析相结合的方法。结果表明从兴安杜鹃根样中分离得到的真菌分属于7个属:Phialocephala、粒毛盘菌属(Lachnum)、膜盘菌属(Hymenoscyphus)、Meliniomyces、丝核菌属(Rhizoctonia)、被孢霉属(Mortierella)和软盘菌属(Mollisia)。其中Phialocephala、粒毛盘菌属(Lachnum)和膜盘菌属(Hymenoscyphus)为兴安杜鹃菌根真菌优势类群,在分离的菌株中所占比率超过了20%。研究表明与兴安杜鹃根共生的真菌类群较丰富。
