To investigate the cembranoid diterpenes from the soft coral Sarcophyton sp. collected in the South China Sea. Repeatedly column chromatography was performed for the isolation and purification. The structures were elu...To investigate the cembranoid diterpenes from the soft coral Sarcophyton sp. collected in the South China Sea. Repeatedly column chromatography was performed for the isolation and purification. The structures were elucidated on the basis of extensive spectral data （IR, MS, 1 D- and 2D-NMR） analysis by comparing with literature data. A new cembranoid diterpene namely sarcophyolide A （1）, together with 7a, 8β-dihydroxydeepoxysarcophine （2） were isolated from this species. The cembranoid diterpenes with 7-1actone could be chemotaxonomic markers of Sarcophyton sp.展开更多
The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lac...The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lactam.展开更多
The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were ...The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.展开更多
The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)...The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)-3-hydroxymegastigm-7-en-9-one(3),(-)-(3R)-3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin(4),(-)-(3R)-8-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one(5),neocnidilide(6),(3S)-butylphthalide(7)and senkyunolide I(8).Their structures were determined by comprehensive spectroscopic methods,including HRESIMS and 1D NMR.展开更多
[2+2]-Type cyclobutane derivatives comprise a large family of natural products with diverse molecular architectures.However,the structure elucidation of the cyclobutane ring,including its connection mode and stereoche...[2+2]-Type cyclobutane derivatives comprise a large family of natural products with diverse molecular architectures.However,the structure elucidation of the cyclobutane ring,including its connection mode and stereochemistry,presents a significant challenge.Plumerubradins A-C(1-3),three novel iridoid glycoside[2+2]dimers featuring a highly functionalized cyclobutane core and multiple stereogenic centers,were isolated from the flowers of Plumeria rubra.Through biomimetic semisynthesis and chemical degradation of compounds 1-3,synthesis of phenylpropanoid-derived[2+2]dimers 7-10,combined with extensive spectroscopic analysis,single-crystal X-ray crystallography,and microcrystal electron diffraction experiments,the structures with absolute configurations of 1-3 were unequivocally elucidated.Furthermore,quantum mechanics-based^(1)H NMR iterative full spin analysis successfully established the correlations between the signal patterns of cyclobutane protons and the structural information of the cyclobutane ring in phenylpropanoid-derived[2+2]dimers,providing a diagnostic tool for the rapid structural elucidation of[2+2]-type cyclobutane derivatives.展开更多
A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene...A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.展开更多
A new class of potent liver injury protective compounds,phychetins A-D(1-4)featuring an unique 6/6/5/6/5 pentacyclic framework,were isolated and structurally characterized from a Chinese medicinal plant Phyllanthus fr...A new class of potent liver injury protective compounds,phychetins A-D(1-4)featuring an unique 6/6/5/6/5 pentacyclic framework,were isolated and structurally characterized from a Chinese medicinal plant Phyllanthus franchetianus.Compounds 2-4 are three pairs of enantiomers that were initially obtained in a racemic manner,and were further separated by chiral HPLC preparation.Compounds 1-4 were proposed to be originated biosynthetically from a coexisting lignan via an intramolecular Friedel-Crafts reaction as the key step.A bioinspired total synthesis strategy was thus designated,and allowed the effective syntheses of compounds 2-4 in high yields.Some of compounds exhibited significant anti-inflammatory activities in vitro via suppressing the production of pro-inflammatory cytokine IL-1β.Notably,compound 4,the most active enantiomeric pair in vitro,displayed prominent potent protecting activity against liver injury at a low dose of 3 mg/kg in mice,which could serve as a promising lead for the development of acute liver injury therapeutic agent.展开更多
Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new m...Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.展开更多
An extract from the female sex gland of Semiothisa cinerearia attracted conspecific males in field tests.A major active component was isolated from the extract and identified by GC-MS,GC-IR and microchemical reactions...An extract from the female sex gland of Semiothisa cinerearia attracted conspecific males in field tests.A major active component was isolated from the extract and identified by GC-MS,GC-IR and microchemical reactions as cis-3,4-cpoxy-(Z,Z)-6,9-heptadecadiene,which showed strong EAG response.Another minor yet important component was identified as (Z,Z,Z)-3,6,9-heptadecatriene.展开更多
The structure of a radiation-protective sulfated polysaccharide, SP-APS, isolated from Spirulina platensis, was investigated by methylation analysis, partial acetolysis and H-1-NMR spectroscopy. The repeating-unit of ...The structure of a radiation-protective sulfated polysaccharide, SP-APS, isolated from Spirulina platensis, was investigated by methylation analysis, partial acetolysis and H-1-NMR spectroscopy. The repeating-unit of SP-APS as branched structures was elucidated.展开更多
Five novel emestrin-type epipolythiodioxopiperazines(ETPs),prenylemestrins C-G(1-5),along with two known ETPs,prenylemestrin A(6)and prenylemestrin B(7),were obtained from Aspergillus nidulans.Their structures were ch...Five novel emestrin-type epipolythiodioxopiperazines(ETPs),prenylemestrins C-G(1-5),along with two known ETPs,prenylemestrin A(6)and prenylemestrin B(7),were obtained from Aspergillus nidulans.Their structures were characterized by spectroscopic data,X-ray crystallographic data,ECD comparisons and calculations.Prenylemestrins C-G(1-5)represent a rare class of ETPs,characterized by a 2,5-dithia-7,9-diazabicyclo[4.2.2]decane-8,10-dione core involving a hemiterpene moiety.Notably,compound 6 exhibited moderate cytotoxicity,inducing G2/M cell cycle arrest and apoptosis of L1210 cells by regulating the PI3K/AKT signaling pathway and mitochondrial apoptotic mechanisms.展开更多
The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mi...The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mixtures 1–5 to 1a/1b–5a/5b was achieved using a chiral column with acetonitrile−water mixtures as eluents.The planar structures of 1–2 were previously undescribed,and the chiral separation and absolute configurations of 3–5 were reported for the first time.Their structures were determined through comprehensive spectroscopic data analysis[nuclear magnetic resonance(NMR),high-resolution electrospray ionization mass(HR-ESI-MS),infrared(IR),and ultraviolet(UV)]and quantum chemistry calculations(ECD).The new isolates were evaluated by measuring their inhibitory effect on NO in lipopolysaccharide(LPS)-stimulated BV-2 cells.Compounds 1a,3a,3b,and 5a demonstrated partial inhibition of NO production in a concentration-dependent manner.Western blot and real-time polymerase chain reaction(PCR)assays revealed that 1a down-regulated the messenger ribonucleic acid(mRNA)levels of tumor necrosis factorα(TNF-α),interleukin-6(IL-6),COX-2,and iNOS and the protein expressions of COX-2 and iNOS.This research provides guidance and evidence for the further development and utilization of I.dunnianum.展开更多
The bioactivity-guided isolation of potentially active natural products has been widely utilized in pharmaceutical discovery.In this study,by screening fungal extracts against coxsackievirus B3(CVB3),three new aspocha...The bioactivity-guided isolation of potentially active natural products has been widely utilized in pharmaceutical discovery.In this study,by screening fungal extracts against coxsackievirus B3(CVB3),three new aspochalasins,templichalasins A-C(1-3),along with six known aspochalasins(4-9)were isolated from an active extract derived from the endophytic fungus Aspergillus templicola LHWf045.Compound 1 features a unique 5/6/5/7/5 pentacyclic ring system,while compounds 2 and 3 possess unusual 5/6/6/7 tetracyclic skeletons.Their structures were characterized through extensive spectroscopic analyses,electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analysis.Additionally,we demonstrated that compound 4 can be readily converted into compounds 1-3 under mild acidic conditions and proposed a plausible mechanism for this conversion.Bioactivity evaluation of compounds 1-9 against CVB3 revealed the inhibitory effects of all compounds against the virus.Notably,compound 9 exhibited superior antiviral activity,surpassing the commercial drug ribavirin in selectivity index(SI)value.展开更多
Seven novel acylphloroglucinol-sesquiterpenoid adducts,designated as dryatraols J-P(1-7),were isolated from the rhizomes of Dryopteris atrata(Wall.ex Kunze)Ching.The structures,including absolute configurations,were e...Seven novel acylphloroglucinol-sesquiterpenoid adducts,designated as dryatraols J-P(1-7),were isolated from the rhizomes of Dryopteris atrata(Wall.ex Kunze)Ching.The structures,including absolute configurations,were elucidated using comprehensive spectroscopic data,calculated 13C Nuclear Magnetic Resonance-Diastereotopic Probability Assignment Plus(13C NMR-DP4+)probability analysis,and ECD calculations.These structures represent a rare subclass of carbon skeleton of acylphloroglucinol-sesquiterpenoid adducts with a furan ring connecting the acylphloroglucinol and sesquiterpenoid moieties.Notably,compounds 1-6 are the first reported examples of acylphloroglucinol-sesquiterpenoid adducts with dimeric acylphloroglucinol incorporated into the aristolane-or rulepidanol-type sesquiterpene,while compound 7 features a hydroxylated monomeric acylphloroglucinol motif.A preliminary evaluation of their antiviral activities revealed that compounds 1-6 exhibited more potent activities against respiratory syncytial virus(RSV)with IC50 values ranging from 0.75 to 3.12μmol·L^(-1) compared to the positive control(ribavirin).展开更多
The Plectranthinae clade,which includes genera such as Plectranthus,Ocimum,and Aeollanthus,is well known for its diverse array of diterpenoids.While numerous studies have deepened the understanding of diterpene divers...The Plectranthinae clade,which includes genera such as Plectranthus,Ocimum,and Aeollanthus,is well known for its diverse array of diterpenoids.While numerous studies have deepened the understanding of diterpene diversity across the clade,Aeollanthus species remain underexplored,with only two studies focusing on their diterpene profiles.The NMR-based chemical profiling of the EtOAc leaf extract of the rocky and succulent species Aeollanthus buchnerianus Briq.reveals a range of diterpenes with isopimarane and abietane skeletons including several previously unreported analogues.Interestingly,the isolated compounds provided insights into the breakdown patterns of both diterpene classes by examining the product ions in their MS2 spectra.These data offer valuable information for evaluating the taxonomic position of this species in relation to other species within the clade.展开更多
Hymoins A–C(1–3),three unusual polycyclic polyprenylated acylphloroglucinols(PPAPs)were isolated from the flowers of Hypericum monogynum.Hymoin A features the first intriguing 6/5/5/5/7 pentacyclic caged PPAP.Hymoin...Hymoins A–C(1–3),three unusual polycyclic polyprenylated acylphloroglucinols(PPAPs)were isolated from the flowers of Hypericum monogynum.Hymoin A features the first intriguing 6/5/5/5/7 pentacyclic caged PPAP.Hymoin B is characterized by an unprecedented rearranged 5/6/8 tricyclic ring system,while hymoin C represents the first rearranged PPAP with a fantastic spirocyclic 5/6/7 ring system.Their structures were established by extensive spectroscopic analysis,X-ray crystallography,and computational methods.The plausible biosynthetic routes for the compounds were also proposed.In oleic acid(OA)-induced HepG2 cells,all compounds exhibited significant lipid-lowering activity at the concentrations of 2–8μmol/L.Further mechanistic study implied that compound 1 exhibited excellent lipid-lowering activity in OA-induced HepG2 cells through inhibiting the proteins of free fatty acids synthesis and improving lipidolysis.展开更多
(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectr...(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectroscopic analysis and HR-ESI-MS data,and their absolute configurations were elucidated using a modified Mosher’s method and electronic circular dichroism(ECD)calculations.(±)-Talapyrones A−F(1−6)possess a 6/6/6 tricyclic skeleton,presumably formed through a Michael addition reaction between one molecule ofα-pyrone derivative and one molecule of C8 poly-β-keto chain.In addition,compounds 2/3 and 4/5 are two pairs of C-18 epimers,respectively.Putative biosynthetic pathways of 1−6 were discussed.展开更多
A chemical investigation of secondary metabolites(SMs)from Aspergillus nidulans resulted in the identification of five novel dioxopiperazine(DKP)-diphenyl ether hybrids,designated as diphenylemestrins A-E(1-5).These c...A chemical investigation of secondary metabolites(SMs)from Aspergillus nidulans resulted in the identification of five novel dioxopiperazine(DKP)-diphenyl ether hybrids,designated as diphenylemestrins A-E(1-5).These compounds 1-5 represent the first known dimers combining DKP and diphenyl ether structures,with compound 4 featuring an uncommon dibenzofuran as the diphenyl ether component.The structural elucidation and determination of absolute stereochemistry were accomplished through spectroscopic analysis and electronic circular dichroism(ECD)calculations.Notably,diphenylemestrin C(3)exhibited moderate cytostatic activity against NB4 cells,with a half maximal inhibitory concentration(IC50)value of 21.99μmol·L-1,and induced apoptosis at higher concentrations.展开更多
(±)-Penicithrones A–D(1a/1b–4a/4b),four novel pairs of anthrone–cyclopentenone heterodimers characterized by a distinctive bridged 6/6/6−5 tetracyclic core skeleton,together with three previously identified co...(±)-Penicithrones A–D(1a/1b–4a/4b),four novel pairs of anthrone–cyclopentenone heterodimers characterized by a distinctive bridged 6/6/6−5 tetracyclic core skeleton,together with three previously identified compounds(5–7),were isolated from the crude extract of the mangrove-derived fungus Penicillium sp.,guided by heteronuclear single quantum correlation(HSQC)-based small molecule accurate recognition technology(SMART 2.0)and liquid chromatography-tandem mass spectrometry(LC-MS/MS)-based molecular networking.The structural elucidation of new compounds was accomplished through comprehensive spectroscopic analysis,and their absolute configurations were determined using DP4+^(13)C nuclear magnetic resonance(NMR)calculations and electronic circular dichroism(ECD)calculations.Compounds 1a/1b–4a/4b demonstrated moderate cytotoxicity against three human cancer cell lines HeLa,HCT116 and MCF-7 with half maximal inhibitory concentration(IC50)values ranging from 15.95±1.64 to 28.56±2.59μmol·L–1.展开更多
A novel and unusual sterol with unsaturation in the△^(5(14)) position,5α-cholesta-8(14),24(25)-diene-3β,6α-diol 1,was isolated from the South China Ses sponge Dysidea sp.The structure and relative stereochemistry ...A novel and unusual sterol with unsaturation in the△^(5(14)) position,5α-cholesta-8(14),24(25)-diene-3β,6α-diol 1,was isolated from the South China Ses sponge Dysidea sp.The structure and relative stereochemistry of 1 was established by spectral analysis and comparison to the spectral data of known sterols.展开更多
基金National Natural Science Foundation of China(Grant No.30672607)the National Hi-Tech Projects(Grant No.2006AA09Z446,2006DFA31100 and 2006AA09Z405)+1 种基金China Uni-PhD Base Project(Grant No.20060001149)International Cooperation Projects of BMBF-MOST.
文摘To investigate the cembranoid diterpenes from the soft coral Sarcophyton sp. collected in the South China Sea. Repeatedly column chromatography was performed for the isolation and purification. The structures were elucidated on the basis of extensive spectral data （IR, MS, 1 D- and 2D-NMR） analysis by comparing with literature data. A new cembranoid diterpene namely sarcophyolide A （1）, together with 7a, 8β-dihydroxydeepoxysarcophine （2） were isolated from this species. The cembranoid diterpenes with 7-1actone could be chemotaxonomic markers of Sarcophyton sp.
文摘The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lactam.
文摘The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.
文摘The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)-3-hydroxymegastigm-7-en-9-one(3),(-)-(3R)-3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin(4),(-)-(3R)-8-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one(5),neocnidilide(6),(3S)-butylphthalide(7)and senkyunolide I(8).Their structures were determined by comprehensive spectroscopic methods,including HRESIMS and 1D NMR.
基金supported by the National Key R&D Program of China(No.2023YFC3503902)the National Natural Science Foundation of China(Nos.82293681(82293680)and 82321004)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(Nos.2022B1515120015 and 2021A1515111021)the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000026)the Science and Technology Projects in Guangzhou(No.202102070001).
文摘[2+2]-Type cyclobutane derivatives comprise a large family of natural products with diverse molecular architectures.However,the structure elucidation of the cyclobutane ring,including its connection mode and stereochemistry,presents a significant challenge.Plumerubradins A-C(1-3),three novel iridoid glycoside[2+2]dimers featuring a highly functionalized cyclobutane core and multiple stereogenic centers,were isolated from the flowers of Plumeria rubra.Through biomimetic semisynthesis and chemical degradation of compounds 1-3,synthesis of phenylpropanoid-derived[2+2]dimers 7-10,combined with extensive spectroscopic analysis,single-crystal X-ray crystallography,and microcrystal electron diffraction experiments,the structures with absolute configurations of 1-3 were unequivocally elucidated.Furthermore,quantum mechanics-based^(1)H NMR iterative full spin analysis successfully established the correlations between the signal patterns of cyclobutane protons and the structural information of the cyclobutane ring in phenylpropanoid-derived[2+2]dimers,providing a diagnostic tool for the rapid structural elucidation of[2+2]-type cyclobutane derivatives.
基金support from the Natural Sciences Foundation of China(82374035)the CAMS Innovation Fund for Medical Sciences(CIFMS,2022-I2M-1-017,China).
文摘A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.
基金Financial support from the National Natural Science Foundations of China(No.22237007,22177121 and 92057116)supported by the grants from Science and Technology Commission of Shanghai Municipality(No.20ZR1467800 and 19431908100,China)。
文摘A new class of potent liver injury protective compounds,phychetins A-D(1-4)featuring an unique 6/6/5/6/5 pentacyclic framework,were isolated and structurally characterized from a Chinese medicinal plant Phyllanthus franchetianus.Compounds 2-4 are three pairs of enantiomers that were initially obtained in a racemic manner,and were further separated by chiral HPLC preparation.Compounds 1-4 were proposed to be originated biosynthetically from a coexisting lignan via an intramolecular Friedel-Crafts reaction as the key step.A bioinspired total synthesis strategy was thus designated,and allowed the effective syntheses of compounds 2-4 in high yields.Some of compounds exhibited significant anti-inflammatory activities in vitro via suppressing the production of pro-inflammatory cytokine IL-1β.Notably,compound 4,the most active enantiomeric pair in vitro,displayed prominent potent protecting activity against liver injury at a low dose of 3 mg/kg in mice,which could serve as a promising lead for the development of acute liver injury therapeutic agent.
文摘Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.
文摘An extract from the female sex gland of Semiothisa cinerearia attracted conspecific males in field tests.A major active component was isolated from the extract and identified by GC-MS,GC-IR and microchemical reactions as cis-3,4-cpoxy-(Z,Z)-6,9-heptadecadiene,which showed strong EAG response.Another minor yet important component was identified as (Z,Z,Z)-3,6,9-heptadecatriene.
基金Project supported by the State Science and Technology Commission of China.
文摘The structure of a radiation-protective sulfated polysaccharide, SP-APS, isolated from Spirulina platensis, was investigated by methylation analysis, partial acetolysis and H-1-NMR spectroscopy. The repeating-unit of SP-APS as branched structures was elucidated.
基金National Natural Science Foundation of China(U22A20380,82173706,82104028)Fundamental Research Funds for the Central Universities(2024BRA018)financially supported this project.
文摘Five novel emestrin-type epipolythiodioxopiperazines(ETPs),prenylemestrins C-G(1-5),along with two known ETPs,prenylemestrin A(6)and prenylemestrin B(7),were obtained from Aspergillus nidulans.Their structures were characterized by spectroscopic data,X-ray crystallographic data,ECD comparisons and calculations.Prenylemestrins C-G(1-5)represent a rare class of ETPs,characterized by a 2,5-dithia-7,9-diazabicyclo[4.2.2]decane-8,10-dione core involving a hemiterpene moiety.Notably,compound 6 exhibited moderate cytotoxicity,inducing G2/M cell cycle arrest and apoptosis of L1210 cells by regulating the PI3K/AKT signaling pathway and mitochondrial apoptotic mechanisms.
基金supported by the Basic Research Program of the Natural Science Fund-Frontier Leading Technology Basic Research Special Project(No.SBK2023050003)by the University Science and Technology Innovation Team of Department of Education of Guizhou Province(No.QJ[2023]099).
文摘The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mixtures 1–5 to 1a/1b–5a/5b was achieved using a chiral column with acetonitrile−water mixtures as eluents.The planar structures of 1–2 were previously undescribed,and the chiral separation and absolute configurations of 3–5 were reported for the first time.Their structures were determined through comprehensive spectroscopic data analysis[nuclear magnetic resonance(NMR),high-resolution electrospray ionization mass(HR-ESI-MS),infrared(IR),and ultraviolet(UV)]and quantum chemistry calculations(ECD).The new isolates were evaluated by measuring their inhibitory effect on NO in lipopolysaccharide(LPS)-stimulated BV-2 cells.Compounds 1a,3a,3b,and 5a demonstrated partial inhibition of NO production in a concentration-dependent manner.Western blot and real-time polymerase chain reaction(PCR)assays revealed that 1a down-regulated the messenger ribonucleic acid(mRNA)levels of tumor necrosis factorα(TNF-α),interleukin-6(IL-6),COX-2,and iNOS and the protein expressions of COX-2 and iNOS.This research provides guidance and evidence for the further development and utilization of I.dunnianum.
基金supported by the National Natural Science Foundation of China(Nos.31972852,32371496,and 81903527)the Key Project at Central Government Level:the Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources(No.2060302)。
文摘The bioactivity-guided isolation of potentially active natural products has been widely utilized in pharmaceutical discovery.In this study,by screening fungal extracts against coxsackievirus B3(CVB3),three new aspochalasins,templichalasins A-C(1-3),along with six known aspochalasins(4-9)were isolated from an active extract derived from the endophytic fungus Aspergillus templicola LHWf045.Compound 1 features a unique 5/6/5/7/5 pentacyclic ring system,while compounds 2 and 3 possess unusual 5/6/6/7 tetracyclic skeletons.Their structures were characterized through extensive spectroscopic analyses,electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analysis.Additionally,we demonstrated that compound 4 can be readily converted into compounds 1-3 under mild acidic conditions and proposed a plausible mechanism for this conversion.Bioactivity evaluation of compounds 1-9 against CVB3 revealed the inhibitory effects of all compounds against the virus.Notably,compound 9 exhibited superior antiviral activity,surpassing the commercial drug ribavirin in selectivity index(SI)value.
基金supported by the National Natural Science Foundation of China(Nos.82173695,82003609 and 82003743)the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515011896 and 2020A1515110453)+1 种基金the Science and Technology Planning Project of Guangzhou City(No.2023A03J0566)the High-performance Public Computing Service Platform of Jinan University.
文摘Seven novel acylphloroglucinol-sesquiterpenoid adducts,designated as dryatraols J-P(1-7),were isolated from the rhizomes of Dryopteris atrata(Wall.ex Kunze)Ching.The structures,including absolute configurations,were elucidated using comprehensive spectroscopic data,calculated 13C Nuclear Magnetic Resonance-Diastereotopic Probability Assignment Plus(13C NMR-DP4+)probability analysis,and ECD calculations.These structures represent a rare subclass of carbon skeleton of acylphloroglucinol-sesquiterpenoid adducts with a furan ring connecting the acylphloroglucinol and sesquiterpenoid moieties.Notably,compounds 1-6 are the first reported examples of acylphloroglucinol-sesquiterpenoid adducts with dimeric acylphloroglucinol incorporated into the aristolane-or rulepidanol-type sesquiterpene,while compound 7 features a hydroxylated monomeric acylphloroglucinol motif.A preliminary evaluation of their antiviral activities revealed that compounds 1-6 exhibited more potent activities against respiratory syncytial virus(RSV)with IC50 values ranging from 0.75 to 3.12μmol·L^(-1) compared to the positive control(ribavirin).
基金funded by a grant to MSJS from Procter and Gamble.
文摘The Plectranthinae clade,which includes genera such as Plectranthus,Ocimum,and Aeollanthus,is well known for its diverse array of diterpenoids.While numerous studies have deepened the understanding of diterpene diversity across the clade,Aeollanthus species remain underexplored,with only two studies focusing on their diterpene profiles.The NMR-based chemical profiling of the EtOAc leaf extract of the rocky and succulent species Aeollanthus buchnerianus Briq.reveals a range of diterpenes with isopimarane and abietane skeletons including several previously unreported analogues.Interestingly,the isolated compounds provided insights into the breakdown patterns of both diterpene classes by examining the product ions in their MS2 spectra.These data offer valuable information for evaluating the taxonomic position of this species in relation to other species within the clade.
基金financially supported by the National Natural Science Foundation of China(Nos.32270413,82060631,82160808,and 82360035)the Science and Technology Department of Guizhou Province(Nos.QKHJC 2020–1Z076,QKHJC-ZK[2023]YB156,QKHJC-ZK[2021]YB569,and QKHPTRC[2020]5008)+4 种基金Excellent Young Talents Plan of Guizhou Medical University(2023,No.106)the 13thbatch of outstanding young scientific and technological talents in Guizhou Province(No.QKHPTRC[2021]5633)Guizhou Science and Technology Innovation Talent Team(No.QKHPTRC–CXTD[2022]007)High-level Innovative Talents in Guizhou Province(Thousand Levels of Talent for Chunmao Yuan in 2018)the project of State Key Laboratory of Functions and Applications of Medicinal Plants,Guizhou Medical University(Nos.FAMP202102K and QJJ[2023]113)。
文摘Hymoins A–C(1–3),three unusual polycyclic polyprenylated acylphloroglucinols(PPAPs)were isolated from the flowers of Hypericum monogynum.Hymoin A features the first intriguing 6/5/5/5/7 pentacyclic caged PPAP.Hymoin B is characterized by an unprecedented rearranged 5/6/8 tricyclic ring system,while hymoin C represents the first rearranged PPAP with a fantastic spirocyclic 5/6/7 ring system.Their structures were established by extensive spectroscopic analysis,X-ray crystallography,and computational methods.The plausible biosynthetic routes for the compounds were also proposed.In oleic acid(OA)-induced HepG2 cells,all compounds exhibited significant lipid-lowering activity at the concentrations of 2–8μmol/L.Further mechanistic study implied that compound 1 exhibited excellent lipid-lowering activity in OA-induced HepG2 cells through inhibiting the proteins of free fatty acids synthesis and improving lipidolysis.
基金supported by the National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(Nos.U22A20380,82173706,and 82104028)the Science and Technology Major Project of Hubei Province(No.2021ACA012).
文摘(±)-Talapyrones A−F(1−6),six pairs of dimeric polyketide enantiomers featuring unusual 6/6/6 and 6/6/6/5 ring systems,were isolated from the fungus Talaromyces adpressus.Their structures were determined by spectroscopic analysis and HR-ESI-MS data,and their absolute configurations were elucidated using a modified Mosher’s method and electronic circular dichroism(ECD)calculations.(±)-Talapyrones A−F(1−6)possess a 6/6/6 tricyclic skeleton,presumably formed through a Michael addition reaction between one molecule ofα-pyrone derivative and one molecule of C8 poly-β-keto chain.In addition,compounds 2/3 and 4/5 are two pairs of C-18 epimers,respectively.Putative biosynthetic pathways of 1−6 were discussed.
基金The National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(Nos.U22A20380,82104028,82173706,and 82373755)+1 种基金the Science and Technology Major Project of Hubei Province(No.2021ACA012)the Fundamental Research Funds for the Central Universities,HUST(No.2021JYCXJJ058)。
文摘A chemical investigation of secondary metabolites(SMs)from Aspergillus nidulans resulted in the identification of five novel dioxopiperazine(DKP)-diphenyl ether hybrids,designated as diphenylemestrins A-E(1-5).These compounds 1-5 represent the first known dimers combining DKP and diphenyl ether structures,with compound 4 featuring an uncommon dibenzofuran as the diphenyl ether component.The structural elucidation and determination of absolute stereochemistry were accomplished through spectroscopic analysis and electronic circular dichroism(ECD)calculations.Notably,diphenylemestrin C(3)exhibited moderate cytostatic activity against NB4 cells,with a half maximal inhibitory concentration(IC50)value of 21.99μmol·L-1,and induced apoptosis at higher concentrations.
基金supported by the National Key Research and Development Program of China(No.2022YFC2303100)the National Natural Science Foundation of China(Nos.32022002 and 21977113).
文摘(±)-Penicithrones A–D(1a/1b–4a/4b),four novel pairs of anthrone–cyclopentenone heterodimers characterized by a distinctive bridged 6/6/6−5 tetracyclic core skeleton,together with three previously identified compounds(5–7),were isolated from the crude extract of the mangrove-derived fungus Penicillium sp.,guided by heteronuclear single quantum correlation(HSQC)-based small molecule accurate recognition technology(SMART 2.0)and liquid chromatography-tandem mass spectrometry(LC-MS/MS)-based molecular networking.The structural elucidation of new compounds was accomplished through comprehensive spectroscopic analysis,and their absolute configurations were determined using DP4+^(13)C nuclear magnetic resonance(NMR)calculations and electronic circular dichroism(ECD)calculations.Compounds 1a/1b–4a/4b demonstrated moderate cytotoxicity against three human cancer cell lines HeLa,HCT116 and MCF-7 with half maximal inhibitory concentration(IC50)values ranging from 15.95±1.64 to 28.56±2.59μmol·L–1.
文摘A novel and unusual sterol with unsaturation in the△^(5(14)) position,5α-cholesta-8(14),24(25)-diene-3β,6α-diol 1,was isolated from the South China Ses sponge Dysidea sp.The structure and relative stereochemistry of 1 was established by spectral analysis and comparison to the spectral data of known sterols.
