[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
Two new glutarimide derivatives,2-hydroxy-3-[2-(2-hydroxy-3-methylphenyl-5-hydroxymethyl)-2-oxoethyl]glutarimide(1)and 2-hydroxy-3-[2-[2-hydroxy-3-hydroxymethyl-5-methylphenyl]-2-oxoethyl]glutarimide(2),along with 8 k...Two new glutarimide derivatives,2-hydroxy-3-[2-(2-hydroxy-3-methylphenyl-5-hydroxymethyl)-2-oxoethyl]glutarimide(1)and 2-hydroxy-3-[2-[2-hydroxy-3-hydroxymethyl-5-methylphenyl]-2-oxoethyl]glutarimide(2),along with 8 known compounds were isolated from the liquid fermentation broth of endophytic Streptomyces sp.YINM00048 obtained from Agrimonia pilosa.Their structures were elucidated through comprehensive spectroscopic analysis,including nuclear magnetic resonance,high-resolution mass spectrometry,and single-crystal X-ray diffraction,supported by time-dependent density functional theory(TDDFT)-electronic circular dichroism(ECD)calculations.Furthermore,compound 2 displayed weak cytotoxic activity against A549 and SMMC-7721 cell lines with IC50 values of 62.69 and 55.07μmol/L,respectively.展开更多
new sesquiterpene-lactone,designated as neopentalenolactone D1(1),was isolated from the fermentation cultures of Streptomyces aureus SP-371,which is known for producing agricultural-bactericide aureonuclemycin.The che...new sesquiterpene-lactone,designated as neopentalenolactone D1(1),was isolated from the fermentation cultures of Streptomyces aureus SP-371,which is known for producing agricultural-bactericide aureonuclemycin.The chemical structure of compound 1 was determined to be a neopentapyrrole natural product with a 5/5/6 tricyclic skeleton and one amide functional group,by using spectroscopic techniques such as nuclear magnetic resonance(1D/2D NMR)and high-resolution mass spectrometry(HR-ESI-MS).Its structural information indicates that it is probably the shunt product of neopentalenolactone biosynthetic pathway.In antibacterial activity evaluations,compound 1 demonstrated no inhibitory effects against the tested strains including Escherichia coli(DH5a),Staphylococcus aureus,and Bacillus subtilis under the experimental conditions.展开更多
Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease marked by motor neuron(MN)degeneration,neuromuscular junction disruption,and muscle atrophy,ultimately leading to paralysis and death.Despit...Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease marked by motor neuron(MN)degeneration,neuromuscular junction disruption,and muscle atrophy,ultimately leading to paralysis and death.Despite extensive research,no effective treatment exists,highlighting the need to elucidate mechanisms driving ALS pathogenesis.About 90%of ALS cases are sporadic ALS and lack a clear genetic cause;the remaining 10%are familial ALS,associated with mutations in over 25 genes.The most common mutations are in superoxide dismutase 1(SOD1)and C9ORF72,with rarer variants in FUS,TARDBP,TBK1,and VCP.展开更多
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
As a key contributor to memory storage, the synapse is one of the earliest affected neuronal components in Alzheimer＇s disease （AD）. Under physiological conditions, the synaptic con- nections between neurons underg...As a key contributor to memory storage, the synapse is one of the earliest affected neuronal components in Alzheimer＇s disease （AD）. Under physiological conditions, the synaptic con- nections between neurons undergo activity-dependent func- tional and morphological re-organisation. This dynamic, ＇plastic＇ neural ability critically depends on the structural integrity of the synapse. Thus, proteins that are implicated in preserving the organisation and dynamics of synaptic connections, including microtubules of the cytoskeleton and associated proteins, have attracted much focus for their involvement in the malfunction- ing AD synapse.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
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
A new prenylated flavonol, maackiaflavonol, was isolated from the ethanol extract of the roots of Maackia tenuifolia. Its structure was elucidated as 7-hydrox-8-prenylflavonol by means of spectroscopic analysis (UV, I...A new prenylated flavonol, maackiaflavonol, was isolated from the ethanol extract of the roots of Maackia tenuifolia. Its structure was elucidated as 7-hydrox-8-prenylflavonol by means of spectroscopic analysis (UV, IR, MS, NMR and 1H-1H COSY) and confirmed by total synthesis.展开更多
A new p-acetylphenyl glycoside,asterbatanoside A has been isolated from the roots of Aster batangensis, and its structure has been elucidated as p-hydroxyacetophenone- -O-α-D-xylopyranosyl-(1,6) -β-D-glucopyranosid...A new p-acetylphenyl glycoside,asterbatanoside A has been isolated from the roots of Aster batangensis, and its structure has been elucidated as p-hydroxyacetophenone- -O-α-D-xylopyranosyl-(1,6) -β-D-glucopyranoside by chemical and spectral means.For the confirmation of this structure. the synthesis of this compound was also reported in this paper.展开更多
On the basis of spectroscopic evidence (MS, ~1HNMR, ^(13)CNMR, CD, ~1H-~1H and ~1H-^(13)C cosy NMR) and chemical synthesis, the structure of isodopharicin E (1), isolated from the dry leaves and tender branches of Iso...On the basis of spectroscopic evidence (MS, ~1HNMR, ^(13)CNMR, CD, ~1H-~1H and ~1H-^(13)C cosy NMR) and chemical synthesis, the structure of isodopharicin E (1), isolated from the dry leaves and tender branches of Isodon pharicus (Prain) Murata was elucidated as 3R, 3'R, 13S, 13'S-tetrahydroxy-11S, 11'S-diacetoxy(16S-O-15')-bisentkaur-15'-en-15-one.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
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.
文摘Two new glutarimide derivatives,2-hydroxy-3-[2-(2-hydroxy-3-methylphenyl-5-hydroxymethyl)-2-oxoethyl]glutarimide(1)and 2-hydroxy-3-[2-[2-hydroxy-3-hydroxymethyl-5-methylphenyl]-2-oxoethyl]glutarimide(2),along with 8 known compounds were isolated from the liquid fermentation broth of endophytic Streptomyces sp.YINM00048 obtained from Agrimonia pilosa.Their structures were elucidated through comprehensive spectroscopic analysis,including nuclear magnetic resonance,high-resolution mass spectrometry,and single-crystal X-ray diffraction,supported by time-dependent density functional theory(TDDFT)-electronic circular dichroism(ECD)calculations.Furthermore,compound 2 displayed weak cytotoxic activity against A549 and SMMC-7721 cell lines with IC50 values of 62.69 and 55.07μmol/L,respectively.
基金supported by the National Natural Science Foundation of China(No.22077134)。
文摘new sesquiterpene-lactone,designated as neopentalenolactone D1(1),was isolated from the fermentation cultures of Streptomyces aureus SP-371,which is known for producing agricultural-bactericide aureonuclemycin.The chemical structure of compound 1 was determined to be a neopentapyrrole natural product with a 5/5/6 tricyclic skeleton and one amide functional group,by using spectroscopic techniques such as nuclear magnetic resonance(1D/2D NMR)and high-resolution mass spectrometry(HR-ESI-MS).Its structural information indicates that it is probably the shunt product of neopentalenolactone biosynthetic pathway.In antibacterial activity evaluations,compound 1 demonstrated no inhibitory effects against the tested strains including Escherichia coli(DH5a),Staphylococcus aureus,and Bacillus subtilis under the experimental conditions.
文摘Amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease marked by motor neuron(MN)degeneration,neuromuscular junction disruption,and muscle atrophy,ultimately leading to paralysis and death.Despite extensive research,no effective treatment exists,highlighting the need to elucidate mechanisms driving ALS pathogenesis.About 90%of ALS cases are sporadic ALS and lack a clear genetic cause;the remaining 10%are familial ALS,associated with mutations in over 25 genes.The most common mutations are in superoxide dismutase 1(SOD1)and C9ORF72,with rarer variants in FUS,TARDBP,TBK1,and VCP.
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.
基金supported by grant SDU2020 to Prof.Bente Finsen and Prof.Martin R.Larsen(COPING AD–Collaborative Project on the Interaction between Neurons and Glia in Alzheimer’s Disease)
文摘As a key contributor to memory storage, the synapse is one of the earliest affected neuronal components in Alzheimer＇s disease （AD）. Under physiological conditions, the synaptic con- nections between neurons undergo activity-dependent func- tional and morphological re-organisation. This dynamic, ＇plastic＇ neural ability critically depends on the structural integrity of the synapse. Thus, proteins that are implicated in preserving the organisation and dynamics of synaptic connections, including microtubules of the cytoskeleton and associated proteins, have attracted much focus for their involvement in the malfunction- ing AD synapse.
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.
文摘A new prenylated flavonol, maackiaflavonol, was isolated from the ethanol extract of the roots of Maackia tenuifolia. Its structure was elucidated as 7-hydrox-8-prenylflavonol by means of spectroscopic analysis (UV, IR, MS, NMR and 1H-1H COSY) and confirmed by total synthesis.
文摘A new p-acetylphenyl glycoside,asterbatanoside A has been isolated from the roots of Aster batangensis, and its structure has been elucidated as p-hydroxyacetophenone- -O-α-D-xylopyranosyl-(1,6) -β-D-glucopyranoside by chemical and spectral means.For the confirmation of this structure. the synthesis of this compound was also reported in this paper.
文摘On the basis of spectroscopic evidence (MS, ~1HNMR, ^(13)CNMR, CD, ~1H-~1H and ~1H-^(13)C cosy NMR) and chemical synthesis, the structure of isodopharicin E (1), isolated from the dry leaves and tender branches of Isodon pharicus (Prain) Murata was elucidated as 3R, 3'R, 13S, 13'S-tetrahydroxy-11S, 11'S-diacetoxy(16S-O-15')-bisentkaur-15'-en-15-one.
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.
