A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear reg...A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.展开更多
Beneficial effects of natural compounds are often attributed to modulation of NO production;however effects produced by plant extracts do not correlate with effects of purified components. The goal of our work was to ...Beneficial effects of natural compounds are often attributed to modulation of NO production;however effects produced by plant extracts do not correlate with effects of purified components. The goal of our work was to study ability of flavonoids and indole-3-carbinol, as well as their combinations to modify NO production, iNOS gene and protein expression in rat tissues. Baicalein and luteolin decreased NO concentration in both intact and LPS-treated animals. Baicalein decreased iNOS gene expression. Luteolin decreased NO production in the liver and heart and number of iNOS-positive cells in the liver of LPS-treated animals. Combination of the two substances did not decrease the NO synthesis triggered by LPS, although it decreased iNOS gene expression. Quercetin decreased NO production in the heart, kidneys and blood of intact rats, but enhanced the LPS effect in testes, spleen and blood on NO production and iNOS protein expression in the liver. Indole-3-carbinol decreased NO concentration in the cerebellum, blood, lungs and skeletal muscles. The drug enhanced the LPS-triggered increase of NO production in all rat organs. It increased iNOS protein expression in intact liver;however it decreased the LPS-triggered outburst of the enzyme biosynthesis. Combination of indole3-carbinol with quercetin decreased NO production in LPS-treated animals however it slightly increased iNOS gene expression. Taken together our results suggest that modifications of NO level in tissues by a natural compound cannot be predicted from data about its effects on NOS expression or activity. Combination of substances can produce an effect differing from that of individual substances. This stresses importance of direct measurements of NO in the tissues.展开更多
Two new and rare bioactive indoles named dalesindoloids A （1） and B （3）, along with 3-（1H-indole-3ylmethyl）-2-oxindole （2）, were characterized from the indole-3-carbinot （13C）-exposed culture of Daldinia esc...Two new and rare bioactive indoles named dalesindoloids A （1） and B （3）, along with 3-（1H-indole-3ylmethyl）-2-oxindole （2）, were characterized from the indole-3-carbinot （13C）-exposed culture of Daldinia eschscholzii. The absolute configuration of 2 was determined by quantum chemical calculations of the electronic circular dichroism （ECD） spectrum. Dalesindoloids A and B were cytotoxic against the leukemia HL-60 cell line with the IC50 values of 1.0 and 7.4 μmol/L, respectively, with the former being inhibitory on Staphylococcus aureus （MIC： 9.1 μmol/L）. The simultaneous characterization of the alkaloids from the 13C-exposed fungal culture highlighted that the 2,3-epoxyindoline motif can be transformed into both lactam and indolin-3-one moieties. This is the first-time description of the 2,3-epoxyindoline chemical versatility and Wagner-Meerwein rearrangement （WMR） reaction in the microbial culture.展开更多
Two skeletally undescribed polyketide-indole hybrids(PIHs), named indolchromins A and B,were generated from indole-3-carbinol(I3 C) in the fungal culture(Daldinia eschscholzii). The indolchromin structures were elucid...Two skeletally undescribed polyketide-indole hybrids(PIHs), named indolchromins A and B,were generated from indole-3-carbinol(I3 C) in the fungal culture(Daldinia eschscholzii). The indolchromin structures were elucidated mainly by their 1 D and 2 D NMR spectra with the former confirmed by the single-crystal X-ray crystallographic analysis. Each indolchromin alkaloid was chirally separated into four isomers, whose absolute configurations were assigned by comparing the recorded circular dichroism(CD) spectra with the electronic CD(ECD) curves computed for all optional stereoisomers. Furthermore, the indolchromin construction pathways in fungal culture were clarified through enzyme inhibition, precursor feeding experiment, and energy calculation. The cascade reactions,including decarboxylative Claisen condensation catalyzed by 8-amino-7-oxononanoate synthase(AONS),C(sp3)-H activation, double bond migration, and Michael addition, all undergone compatibly during the fungal cultivation. In an MIC range of 1.3–8.6 μmol/L,(2 S,4 R)-and(2 R,4 S)-indolchromin A and(2 R,4 S)-indolchromin B are inhibitory against Clostridium perfringens, Clostridium difficile, Veillonella sp.,Bacteroides fragilis, and Streptococcus pyogenes.(2 R,4 S)-Indolchromin A and(2 S,4 S)-indolchromin B were cytotoxic against the human breast cancer cell line MDA-MB-231 with IC50 values of 27.9 and131.2 nmol/L, respectively, with the former additionally active against another human breast cancer cell line MCF-7(IC_(50)94.4 nmol/L).展开更多
基金Projects(20775010, 21075011) supported by the National Natural Science Foundation of ChinaProject(2008AA05Z405) supported by the National High-tech Research and Development Program of China+2 种基金Project(09JJ3016) supported by the Natural Science Foundation of Hunan Province, ChinaProject(09C066) supported by the Scientific Research Fund of Hunan Provincial Education Department, ChinaProject(2010CL01) supported by the Foundation of Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, China
文摘A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.
文摘Beneficial effects of natural compounds are often attributed to modulation of NO production;however effects produced by plant extracts do not correlate with effects of purified components. The goal of our work was to study ability of flavonoids and indole-3-carbinol, as well as their combinations to modify NO production, iNOS gene and protein expression in rat tissues. Baicalein and luteolin decreased NO concentration in both intact and LPS-treated animals. Baicalein decreased iNOS gene expression. Luteolin decreased NO production in the liver and heart and number of iNOS-positive cells in the liver of LPS-treated animals. Combination of the two substances did not decrease the NO synthesis triggered by LPS, although it decreased iNOS gene expression. Quercetin decreased NO production in the heart, kidneys and blood of intact rats, but enhanced the LPS effect in testes, spleen and blood on NO production and iNOS protein expression in the liver. Indole-3-carbinol decreased NO concentration in the cerebellum, blood, lungs and skeletal muscles. The drug enhanced the LPS-triggered increase of NO production in all rat organs. It increased iNOS protein expression in intact liver;however it decreased the LPS-triggered outburst of the enzyme biosynthesis. Combination of indole3-carbinol with quercetin decreased NO production in LPS-treated animals however it slightly increased iNOS gene expression. Taken together our results suggest that modifications of NO level in tissues by a natural compound cannot be predicted from data about its effects on NOS expression or activity. Combination of substances can produce an effect differing from that of individual substances. This stresses importance of direct measurements of NO in the tissues.
基金We thank the National Natural Science Foundation of China （Nos. 81530089, 81503232, 21672101, and 21661140001） and State Project for Essential Drug Research and Development （No. 2018ZX09711001-007-004） for generous support.
文摘Two new and rare bioactive indoles named dalesindoloids A （1） and B （3）, along with 3-（1H-indole-3ylmethyl）-2-oxindole （2）, were characterized from the indole-3-carbinot （13C）-exposed culture of Daldinia eschscholzii. The absolute configuration of 2 was determined by quantum chemical calculations of the electronic circular dichroism （ECD） spectrum. Dalesindoloids A and B were cytotoxic against the leukemia HL-60 cell line with the IC50 values of 1.0 and 7.4 μmol/L, respectively, with the former being inhibitory on Staphylococcus aureus （MIC： 9.1 μmol/L）. The simultaneous characterization of the alkaloids from the 13C-exposed fungal culture highlighted that the 2,3-epoxyindoline motif can be transformed into both lactam and indolin-3-one moieties. This is the first-time description of the 2,3-epoxyindoline chemical versatility and Wagner-Meerwein rearrangement （WMR） reaction in the microbial culture.
基金supported by the National Natural Science Foundation of China(Grant Nos.81530089,21661140001,21672101,and 81503232)National Key R&D Program of China(2018YFC1706200)the Drug Innovation Major Project(2018ZX09711-001-007-004,China)for generous support
文摘Two skeletally undescribed polyketide-indole hybrids(PIHs), named indolchromins A and B,were generated from indole-3-carbinol(I3 C) in the fungal culture(Daldinia eschscholzii). The indolchromin structures were elucidated mainly by their 1 D and 2 D NMR spectra with the former confirmed by the single-crystal X-ray crystallographic analysis. Each indolchromin alkaloid was chirally separated into four isomers, whose absolute configurations were assigned by comparing the recorded circular dichroism(CD) spectra with the electronic CD(ECD) curves computed for all optional stereoisomers. Furthermore, the indolchromin construction pathways in fungal culture were clarified through enzyme inhibition, precursor feeding experiment, and energy calculation. The cascade reactions,including decarboxylative Claisen condensation catalyzed by 8-amino-7-oxononanoate synthase(AONS),C(sp3)-H activation, double bond migration, and Michael addition, all undergone compatibly during the fungal cultivation. In an MIC range of 1.3–8.6 μmol/L,(2 S,4 R)-and(2 R,4 S)-indolchromin A and(2 R,4 S)-indolchromin B are inhibitory against Clostridium perfringens, Clostridium difficile, Veillonella sp.,Bacteroides fragilis, and Streptococcus pyogenes.(2 R,4 S)-Indolchromin A and(2 S,4 S)-indolchromin B were cytotoxic against the human breast cancer cell line MDA-MB-231 with IC50 values of 27.9 and131.2 nmol/L, respectively, with the former additionally active against another human breast cancer cell line MCF-7(IC_(50)94.4 nmol/L).
