Objective: To investigate antimicrobial activities of methanolic extract of leaves of Cleistocalyx operculatus L.(C. operculatus) grown in Vietnam.Methods: The methanolic extract of C. operculatus leaves was phytochem...Objective: To investigate antimicrobial activities of methanolic extract of leaves of Cleistocalyx operculatus L.(C. operculatus) grown in Vietnam.Methods: The methanolic extract of C. operculatus leaves was phytochemically screened and tested for its antimicrobial activity against six Gram-positive bacteria(three of which were antibiotic multiresistant Staphylococcus spp.), two Gram-negative bacteria,and one fungal species using an agar diffusion method. Anticaries activity was tested using p H drop and biofilm assays formed in 96-well plastic plates.Results: Phytochemical screening revealed the presence of flavonoids and terpenes, in which flavonoid content was 6.8 mg/g dry material. Antibacterial activity of the C. operculatus extract was shown only against Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis and Streptococcus mutans GS-5(S. mutans), and three multiresistant bacteria being Staphylococcus epidermidis 847, Staphylococcus haemolyticus 535 and Staphylococcus aureus North German epidemic strain. Interestingly, methanolic extract of C. operculatus leaves exhibited the anticaries activity against S. mutans in terms of inhibition of acid production and biofilm formation. Activity of two key enzymes responsible for acidogenicity of S. mutans, F-ATPase and phosphotransferase system were inhibited by the extract with IC_(50) of 51.0 and 98.0 m g/m L, respectively. Cytotoxicity of the extract against keratinocytes was found only for higher concentrations [IC_(50)=(119.98 ± 4.63) m g/m L].Conclusions: The methanolic extract of C. operculatus leaves has the potential for development of antimicrobial preparations, especially anticaries products.展开更多
The building blocks-based molecular network(BBMN)strategy was applied to the phytochemical investigation of Cleistocalyx operculatus,leading to the targeted isolation of eighteen novel cinnamoylphloroglucinol-terpene ...The building blocks-based molecular network(BBMN)strategy was applied to the phytochemical investigation of Cleistocalyx operculatus,leading to the targeted isolation of eighteen novel cinnamoylphloroglucinol-terpene adducts(CPTAs)with diverse skeleton types(cleistoperones A-R,1-18).Their structures including absolute configurations were determined by extensive spectroscopic methods,quantum chemical calculations,and single-crystal X-ray crystallographic experiments.Cleistoperone A(1),consisting of a cinnamoylphloroglucinol motif and two linear monoterpene moieties,represents an unprecedented macrocyclic CPTA,whose densely functionalized tricyclo[15.3.1.0^(3,8)]heneicosane bridge ring skeleton contains an enolizableβ,β′-triketone system and two different kinds of stereogenic elements(including five point and three planar chiralities).Cleistoperones B and C(2 and 3)are two new skeletal CPTAs with an unusual coupling pattern between the(nor)monoterpene moiety and the cinnamoyl chain of the cinnamoylphloroglucinol unit.Cleistoperone D(4)possesses an unprecedented cage-like 6/6/6/4/6-fused heteropentacyclic scaffold.The plausible biosynthetic pathways for 1-18 were also proposed.Notably,compounds 1,4,7,8,and 18 exhibited significant antiviral activity against respiratory syncytial virus(RSV).The most potent one,cleistoperone A(1)with IC_(50) value of 1.71±0.61μmol/L,could effectively inhibit virus replication via affecting the Akt/mTOR/p70S6K signaling pathway.展开更多
基金Supported by The German Academic Exchange Service(DAAD)funding for Phuong T.M.Nguyen(Reference No.91562658)in 2015
文摘Objective: To investigate antimicrobial activities of methanolic extract of leaves of Cleistocalyx operculatus L.(C. operculatus) grown in Vietnam.Methods: The methanolic extract of C. operculatus leaves was phytochemically screened and tested for its antimicrobial activity against six Gram-positive bacteria(three of which were antibiotic multiresistant Staphylococcus spp.), two Gram-negative bacteria,and one fungal species using an agar diffusion method. Anticaries activity was tested using p H drop and biofilm assays formed in 96-well plastic plates.Results: Phytochemical screening revealed the presence of flavonoids and terpenes, in which flavonoid content was 6.8 mg/g dry material. Antibacterial activity of the C. operculatus extract was shown only against Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis and Streptococcus mutans GS-5(S. mutans), and three multiresistant bacteria being Staphylococcus epidermidis 847, Staphylococcus haemolyticus 535 and Staphylococcus aureus North German epidemic strain. Interestingly, methanolic extract of C. operculatus leaves exhibited the anticaries activity against S. mutans in terms of inhibition of acid production and biofilm formation. Activity of two key enzymes responsible for acidogenicity of S. mutans, F-ATPase and phosphotransferase system were inhibited by the extract with IC_(50) of 51.0 and 98.0 m g/m L, respectively. Cytotoxicity of the extract against keratinocytes was found only for higher concentrations [IC_(50)=(119.98 ± 4.63) m g/m L].Conclusions: The methanolic extract of C. operculatus leaves has the potential for development of antimicrobial preparations, especially anticaries products.
基金supported by the National Key R&D Program of China(No.2023YFC3503902,China)the National Natural Science Foundation of China(Nos.82293681(82293680)+6 种基金82321004,82204234,and 82273822,China)the Guangdong Basic and Applied Basic Research Foundation(Nos.2022B1515120015 and 2021A1515111021,China)the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000026,China)the Guangdong-Hong Kong-Macao Universities Joint Laboratory for the Internationalization of Traditional Chinese Medicine(No.2023LSYS002,China)the Guangzhou Key Laboratory of Traditional Chinese Medicine&Disease Susceptibility(No.2024A03J090,China)the Science and Technology Projects in Guangzhou(No.202102070001,China)supported by the high-performance computing platform of Jinan University.
文摘The building blocks-based molecular network(BBMN)strategy was applied to the phytochemical investigation of Cleistocalyx operculatus,leading to the targeted isolation of eighteen novel cinnamoylphloroglucinol-terpene adducts(CPTAs)with diverse skeleton types(cleistoperones A-R,1-18).Their structures including absolute configurations were determined by extensive spectroscopic methods,quantum chemical calculations,and single-crystal X-ray crystallographic experiments.Cleistoperone A(1),consisting of a cinnamoylphloroglucinol motif and two linear monoterpene moieties,represents an unprecedented macrocyclic CPTA,whose densely functionalized tricyclo[15.3.1.0^(3,8)]heneicosane bridge ring skeleton contains an enolizableβ,β′-triketone system and two different kinds of stereogenic elements(including five point and three planar chiralities).Cleistoperones B and C(2 and 3)are two new skeletal CPTAs with an unusual coupling pattern between the(nor)monoterpene moiety and the cinnamoyl chain of the cinnamoylphloroglucinol unit.Cleistoperone D(4)possesses an unprecedented cage-like 6/6/6/4/6-fused heteropentacyclic scaffold.The plausible biosynthetic pathways for 1-18 were also proposed.Notably,compounds 1,4,7,8,and 18 exhibited significant antiviral activity against respiratory syncytial virus(RSV).The most potent one,cleistoperone A(1)with IC_(50) value of 1.71±0.61μmol/L,could effectively inhibit virus replication via affecting the Akt/mTOR/p70S6K signaling pathway.
