Host–guest molecular recognition at the liquid–liquid interface endows the interface with unique properties,including stimuli-responsiveness and self-regulation,due to the dynamic and reversible nature of non-covale...Host–guest molecular recognition at the liquid–liquid interface endows the interface with unique properties,including stimuli-responsiveness and self-regulation,due to the dynamic and reversible nature of non-covalent interactions.Increasing research efforts have been put into the preparation of supramolecular interfacial systems such as films and microcapsules by integrating functional components(e.g.,colloidal particles,polymers)at the interface,providing tremendous opportunities in the areas of encapsulation,delivery vehicles,and biphasic reaction systems.In this review,we summarize recent progress in supramolecular interfacial systems assembled by host–guest chemistry,and provide an overview of the fabrication process,functions,and promising applications of the resultant constructs.展开更多
Summary of main observation and conclusion Collismycins(COLs)are antibiotics characterized by a 2,2'-bipyridine(2,2'-BP)core composed of a trisubstituted ring A and an unmodified ring B.The 2,2'-BP core,wh...Summary of main observation and conclusion Collismycins(COLs)are antibiotics characterized by a 2,2'-bipyridine(2,2'-BP)core composed of a trisubstituted ring A and an unmodified ring B.The 2,2'-BP core,which possesses metal-chelating ability and plays key roles in various biological activities of COLs,is biosynthesized by a nonribosomal peptide synthetase(NRPS)-polyketide synthase(PKS)hybrid machinery.The starter module of the NRPS-PKS hybrid machinery consists of a type II peptidyl carrier protein(PCP)ColA1a and an adenylation protein ColA1b.We here report the functional characterization of ColAia and ColAlb in vitro,confirming their functions in selection and loading of picolinic acid(PA),instead of normal amino acid substrates,as the origin of ring B in COLs.The 2.1 A crystal structure of ColAia was solved,revealing structural features including the additional helices ala,alb and missing helix a3,which may reflect unique interactions of ColAia with other NRPS-PKS proteins/domains or substrate.Primary and tertiary structural comparison of ColAia with other PCPs revealed the structural basis for their typical a-helical bundle,providing a better understanding of the structural flexibility of PCPs.These results facilitate the starter module engineering for the generation of COL derivatives with ring B modifications in the future.展开更多
WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide...WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide skeleton,which is biosynthesized by nonribosomal peptide synthetases(NRPS).The regioselective cyclization in the last step of NRPS catalysis,which is proposed to be catalyzed by a thioesterase(TE)domain in the last module,has not been experimentally characterized.We here report the synthesis of two substrate mimics(1 and 2)of the TE(WS9326 A-TE)in WS9326 A biosynthesis,by using Fmoc-based solid-phase peptide synthesis(SPPS)method.Compounds 1 and 2 are new compounds whose structures have been elucidated based on NMR and HRESIMS analyses.The N-terminal cinnamoyl moiety and C-terminal methylated L-Ser moiety in 2 were incorporated under the mild SPPS conditions.Given the isolation difficulties of substrate of WS9326 A-TE from the Streptomyces producers of WS9326 A,our synthesis of 1 and 2 set the stage for the reconstitution of WS9326 A-TE’s catalytic reaction in vitro in the future.展开更多
Tryptamine-derived natural products have been discovered from different sources including animals, plants and bacteria,and they show various biological activities. However, they are not discovered widely compared with...Tryptamine-derived natural products have been discovered from different sources including animals, plants and bacteria,and they show various biological activities. However, they are not discovered widely compared with the large amounts of tryptamine derivatives generated by chemical synthesis. We here report the discovery of five tryptamine-derived natural products(1-5) and one known polyketide 6 from Bacillus sp. PKU-TA00001. Compounds 1 and 2 are new compounds featuring methyl-hexanamide moieties, compound 4 is first discovered as a natural product, and 3 and 4’s NMR data are first provided. All compounds showed MIC(minimum inhibitory concentration) values higher than 50 μM against several Gram-positive and negative strains, and showed no cytotoxicity at the concentration of 100 μM against the human cancer cell lines A549, HCT-8 and MCF-7. The discovery of 1-4 expands the structural diversity of tryptamine-derived natural products, and sets the stage for revealing their biosynthetic mechanisms and biological activities in the future.展开更多
基金This work was supported by National Natural Science Foundation of China(51903011)Thomas P.Russell was supported by the US Department of Energy,Office of Science,Office of Basic Energy Sciences,Materials Sciences and Engineering Division under Contract No.DE-AC02-05-CH11231 within the Adaptive Interfacial Assemblies Towards Structuring Liquids program(KCTR16).
文摘Host–guest molecular recognition at the liquid–liquid interface endows the interface with unique properties,including stimuli-responsiveness and self-regulation,due to the dynamic and reversible nature of non-covalent interactions.Increasing research efforts have been put into the preparation of supramolecular interfacial systems such as films and microcapsules by integrating functional components(e.g.,colloidal particles,polymers)at the interface,providing tremendous opportunities in the areas of encapsulation,delivery vehicles,and biphasic reaction systems.In this review,we summarize recent progress in supramolecular interfacial systems assembled by host–guest chemistry,and provide an overview of the fabrication process,functions,and promising applications of the resultant constructs.
基金This research was supported in part by the National Natural Science Foundation of China(Nos.81673332,81573326,21877002 and 81991525)the China Postdoctoral Science Foundation(Nos.2019M660362 and 2018M641123).
文摘Summary of main observation and conclusion Collismycins(COLs)are antibiotics characterized by a 2,2'-bipyridine(2,2'-BP)core composed of a trisubstituted ring A and an unmodified ring B.The 2,2'-BP core,which possesses metal-chelating ability and plays key roles in various biological activities of COLs,is biosynthesized by a nonribosomal peptide synthetase(NRPS)-polyketide synthase(PKS)hybrid machinery.The starter module of the NRPS-PKS hybrid machinery consists of a type II peptidyl carrier protein(PCP)ColA1a and an adenylation protein ColA1b.We here report the functional characterization of ColAia and ColAlb in vitro,confirming their functions in selection and loading of picolinic acid(PA),instead of normal amino acid substrates,as the origin of ring B in COLs.The 2.1 A crystal structure of ColAia was solved,revealing structural features including the additional helices ala,alb and missing helix a3,which may reflect unique interactions of ColAia with other NRPS-PKS proteins/domains or substrate.Primary and tertiary structural comparison of ColAia with other PCPs revealed the structural basis for their typical a-helical bundle,providing a better understanding of the structural flexibility of PCPs.These results facilitate the starter module engineering for the generation of COL derivatives with ring B modifications in the future.
基金National Natural Science Foundation of China(Grant No.21877002,81673332,81573326 and 81741148)
文摘WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide skeleton,which is biosynthesized by nonribosomal peptide synthetases(NRPS).The regioselective cyclization in the last step of NRPS catalysis,which is proposed to be catalyzed by a thioesterase(TE)domain in the last module,has not been experimentally characterized.We here report the synthesis of two substrate mimics(1 and 2)of the TE(WS9326 A-TE)in WS9326 A biosynthesis,by using Fmoc-based solid-phase peptide synthesis(SPPS)method.Compounds 1 and 2 are new compounds whose structures have been elucidated based on NMR and HRESIMS analyses.The N-terminal cinnamoyl moiety and C-terminal methylated L-Ser moiety in 2 were incorporated under the mild SPPS conditions.Given the isolation difficulties of substrate of WS9326 A-TE from the Streptomyces producers of WS9326 A,our synthesis of 1 and 2 set the stage for the reconstitution of WS9326 A-TE’s catalytic reaction in vitro in the future.
基金National Natural Science Foundation of China(Grant No.81673332,81573326,81741148)
文摘Tryptamine-derived natural products have been discovered from different sources including animals, plants and bacteria,and they show various biological activities. However, they are not discovered widely compared with the large amounts of tryptamine derivatives generated by chemical synthesis. We here report the discovery of five tryptamine-derived natural products(1-5) and one known polyketide 6 from Bacillus sp. PKU-TA00001. Compounds 1 and 2 are new compounds featuring methyl-hexanamide moieties, compound 4 is first discovered as a natural product, and 3 and 4’s NMR data are first provided. All compounds showed MIC(minimum inhibitory concentration) values higher than 50 μM against several Gram-positive and negative strains, and showed no cytotoxicity at the concentration of 100 μM against the human cancer cell lines A549, HCT-8 and MCF-7. The discovery of 1-4 expands the structural diversity of tryptamine-derived natural products, and sets the stage for revealing their biosynthetic mechanisms and biological activities in the future.
