From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were establish...From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were established as cyclo (Pro(1)-Phe-Leu-Ala(1)-Thr-Pro(2)-Ala(2)-Gly) (1), cyclo (Pro(1)-Ala-Phe-Trp-Asp-Pro(2)-Leu-Gly) (2), cyclo (Pro(1)-Ile-Gly-Pro(2)-Val-Ala(1)-Ala(2)-Tyr) (3) and cyclo ( Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (4) respectively by means of extensive spectral methods.展开更多
Brachystemma calycinum D. Don as an important rare medicinal plant, the market prospect is very promising. In this paper, the resource distribution, ecological environment, community structure, domestication of wild c...Brachystemma calycinum D. Don as an important rare medicinal plant, the market prospect is very promising. In this paper, the resource distribution, ecological environment, community structure, domestication of wild cultivar and market demand and status of Brachystemma calycinum were systematically studied, so as to provide a basis for resource development and utilization.展开更多
Four novel Daphniphyllum alkaloids with highly rearranged skeletons involving a 6/5/7/7/5 pentacyclic scaffold(1),a 6/5/7/5/6/5/6 heptacyclic scaffold(2 and 4),and a 6/5/7/5/6/5 hexacyclic scaffold(3),were isolated fr...Four novel Daphniphyllum alkaloids with highly rearranged skeletons involving a 6/5/7/7/5 pentacyclic scaffold(1),a 6/5/7/5/6/5/6 heptacyclic scaffold(2 and 4),and a 6/5/7/5/6/5 hexacyclic scaffold(3),were isolated from Daphniphyllum calycinum.Particularly,compound 1 contains a unique 13-oxa-17-azapentacyclo[7.6.4.1^(12,15).0^(4,8).0^(9,15)]eicosane core.Their structures were elucidated by comprehensive spectroscopic analyses,single-crystal X-ray diffraction,and electronic circular dichroism calculations.Putative biosynthetic pathways for compounds 1–4 were discussed with caldaphnidine C(5)as their biosynthetic precursor.Compound 2 markedly enhanced the survival of H9c2 cardiomyocytes under oxygen glucose deprivation and reoxygenation conditions.Mechanistic study revealed that 2 exerted its cardioprotective effects by activating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1(Nrf2/HO-1)antioxidant pathway,thereby enhancing cellular antioxidant capacity and alleviating oxidative stress induced by hypoxia.展开更多
Fivenovel Daphniphyllum alkaloids,named dcalycinumines A-E(1-4,6),andeight previously described Daphniphyllum alkaloids(5,7-13)were isolated from Daphniphyllum calycinum.Compound 1 is the first Daphniphyllum alkaloid ...Fivenovel Daphniphyllum alkaloids,named dcalycinumines A-E(1-4,6),andeight previously described Daphniphyllum alkaloids(5,7-13)were isolated from Daphniphyllum calycinum.Compound 1 is the first Daphniphyllum alkaloid possessing a highly rearranged 6/6/6/7/5/6 hexacyclic architecture with a unique 3-methyl-1-azabicyclo[4,4,0]decane ring system.Compound 2 represents a rare diamino Daphniphyllum alkaloid with an unprecedented 6/5/5/6/6/5 carbon skeleton featuring a unique 1-aza-6-azaspiro[4,5]decane unit,whereas 3 also represents a rare diamino Daphniphyllum alkaloid as a possible precursor of 2.Compound 4 is the second example of c-22-nor yuzurimine-type alkaloids.Their structures and absolute configurations were elucidated by HRESIMS,NMR spectroscopic analyses,EcD calculations,and single-crystal X-ray diffraction.Moreover,compound 1 showed remarkable antitumor activities,which could inhibit the proliferation,migration and invasion of nasopharyngeal carcinoma cells,and promoted nasopharyngeal carcinoma cells apoptosis.展开更多
文摘From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were established as cyclo (Pro(1)-Phe-Leu-Ala(1)-Thr-Pro(2)-Ala(2)-Gly) (1), cyclo (Pro(1)-Ala-Phe-Trp-Asp-Pro(2)-Leu-Gly) (2), cyclo (Pro(1)-Ile-Gly-Pro(2)-Val-Ala(1)-Ala(2)-Tyr) (3) and cyclo ( Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (4) respectively by means of extensive spectral methods.
基金Supported by the Special Fund for Major Research Program of Guangxi Province(GKZ1298001-1-8)Medical Treatment and Public Health Research and Development Project of Guangxi Province(S201416-02)~~
文摘Brachystemma calycinum D. Don as an important rare medicinal plant, the market prospect is very promising. In this paper, the resource distribution, ecological environment, community structure, domestication of wild cultivar and market demand and status of Brachystemma calycinum were systematically studied, so as to provide a basis for resource development and utilization.
基金supported by the National Natural Science Foundation of China(Nos.82273803 and 82173695)the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515011896 and 2020A1515110453)+2 种基金Guangzhou Basic and Applied Basic Research(Nos.SL2024A04J0113 and 202102080022)Fundamental Research Funds for the Central Universities(No.21623224)the high-performance public computing service platform of Jinan University。
文摘Four novel Daphniphyllum alkaloids with highly rearranged skeletons involving a 6/5/7/7/5 pentacyclic scaffold(1),a 6/5/7/5/6/5/6 heptacyclic scaffold(2 and 4),and a 6/5/7/5/6/5 hexacyclic scaffold(3),were isolated from Daphniphyllum calycinum.Particularly,compound 1 contains a unique 13-oxa-17-azapentacyclo[7.6.4.1^(12,15).0^(4,8).0^(9,15)]eicosane core.Their structures were elucidated by comprehensive spectroscopic analyses,single-crystal X-ray diffraction,and electronic circular dichroism calculations.Putative biosynthetic pathways for compounds 1–4 were discussed with caldaphnidine C(5)as their biosynthetic precursor.Compound 2 markedly enhanced the survival of H9c2 cardiomyocytes under oxygen glucose deprivation and reoxygenation conditions.Mechanistic study revealed that 2 exerted its cardioprotective effects by activating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1(Nrf2/HO-1)antioxidant pathway,thereby enhancing cellular antioxidant capacity and alleviating oxidative stress induced by hypoxia.
基金supported by grants from the National Natural Science Foundation of China(Nos.82173695,82273803,82003743,81973190)the Guangdong Basic and Applied Basic Research Foundation(No.2020B1515020033)Scienceand Technology Planning Projectof Guangzhou City(No.202201010485).
文摘Fivenovel Daphniphyllum alkaloids,named dcalycinumines A-E(1-4,6),andeight previously described Daphniphyllum alkaloids(5,7-13)were isolated from Daphniphyllum calycinum.Compound 1 is the first Daphniphyllum alkaloid possessing a highly rearranged 6/6/6/7/5/6 hexacyclic architecture with a unique 3-methyl-1-azabicyclo[4,4,0]decane ring system.Compound 2 represents a rare diamino Daphniphyllum alkaloid with an unprecedented 6/5/5/6/6/5 carbon skeleton featuring a unique 1-aza-6-azaspiro[4,5]decane unit,whereas 3 also represents a rare diamino Daphniphyllum alkaloid as a possible precursor of 2.Compound 4 is the second example of c-22-nor yuzurimine-type alkaloids.Their structures and absolute configurations were elucidated by HRESIMS,NMR spectroscopic analyses,EcD calculations,and single-crystal X-ray diffraction.Moreover,compound 1 showed remarkable antitumor activities,which could inhibit the proliferation,migration and invasion of nasopharyngeal carcinoma cells,and promoted nasopharyngeal carcinoma cells apoptosis.
