Objective:To isolate,purify,and characterize gossypol from the fruits of Thespesia populnea(L)Sol.ex Correa,test its antidermatophytic activity,identify its targets on the dermatophyte,and confirm the binding of gossy...Objective:To isolate,purify,and characterize gossypol from the fruits of Thespesia populnea(L)Sol.ex Correa,test its antidermatophytic activity,identify its targets on the dermatophyte,and confirm the binding of gossypol with the fungal target by molecular docking study.Methods:Gossypol from Thespesia populnea was characterized by high performance liquid chromatography,liquid chromatographmass spectrometry,Fourier transform infrared spectroscopy,and nuclear magnetic resonance.The anti-dermatophytic activity of gossypol was tested against four different dermatophytes,viz.Trichophyton mentagrophytes,Trichophyton rubrum,Microsporum canis,and Microsporum gypseum.Trichophyton mentagrophytes was selected for further studies.The inhibitory mode of action of gossypol on Trichophyton mentagrophytes was determined by analyzing the modulation of gene expression in various pathways of the dermatophyte.Results:Gossypol inhibited all the dermatophytes.The minimum inhibitory concentrations were 12.5μg/mL for Trichophyton mentagrophytes and Microsporum canis and 25μg/mL for Trichophyton rubrum and Microsporum gypseum.The minimum fungicidal concentrations were 50μg/mL for Trichophyton mentagrophytes,100μg/mL for Microsporum canis and Trichophyton rubrum,and 200μg/mL for Microsporum gypseum.Gossypol inhibited the mRNA expression of metalloprotease(MEP4)and isocitrate lyase(ICL).The binding of gossypol with the enzymes was confirmed by molecular docking studies.The best docking poses were found and the low binding energies were recorded with the two target enzymes.Conclusions:Gossypol is a potential antifungal agent and can be further explored as an anti-dermatophytic drug.展开更多
Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occ...Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occurs, cytosolic sesquiterpenes are assumed to derive mainly from MVA, while plastidial monoterpenes are produced preferentially from MEP precursors. Additional complexity arises in the first step of the MEP pathway, which is typically catalyzed by two divergent 1-deoxy-D-xylulose 5-phosphate synthase isoforms （DXS1, DXS2）. In tomato （Solanum lycopersicum）, the SIDXS1 gene is ubiquitously expressed with highest levels during fruit ripening, whereas SIDXS2 transcripts are abundant in only few tissues, including young leaves, petals, and isolated trichomes. Specific down-regulation of SIDXS2 expression was performed by RNA interference in transgenic plants to investigate feedback mechanisms. SIDXS2 down-regulation led to a decrease in the monoterpene β-phellandrene and an increase in two sesquiterpenes in trichomes. Moreover, incorporation of MVA-derived precursors into residual monoterpenes and into sesquiterpenes was elevated as determined by comparison of ^13C to ^12C natural isotope ratios. A compensatory up-regulation of SIDXS1 was not observed. Down-regulated lines also exhibited increased trichome density and showed less damage by leaf-feeding Spodoptera littoralis caterpillars. The results reveal novel, non-redundant roles of DXS2 in modulating isoprenoid metabolism and a pronounced plasticity in isoprenoid precursor allocation.展开更多
文摘Objective:To isolate,purify,and characterize gossypol from the fruits of Thespesia populnea(L)Sol.ex Correa,test its antidermatophytic activity,identify its targets on the dermatophyte,and confirm the binding of gossypol with the fungal target by molecular docking study.Methods:Gossypol from Thespesia populnea was characterized by high performance liquid chromatography,liquid chromatographmass spectrometry,Fourier transform infrared spectroscopy,and nuclear magnetic resonance.The anti-dermatophytic activity of gossypol was tested against four different dermatophytes,viz.Trichophyton mentagrophytes,Trichophyton rubrum,Microsporum canis,and Microsporum gypseum.Trichophyton mentagrophytes was selected for further studies.The inhibitory mode of action of gossypol on Trichophyton mentagrophytes was determined by analyzing the modulation of gene expression in various pathways of the dermatophyte.Results:Gossypol inhibited all the dermatophytes.The minimum inhibitory concentrations were 12.5μg/mL for Trichophyton mentagrophytes and Microsporum canis and 25μg/mL for Trichophyton rubrum and Microsporum gypseum.The minimum fungicidal concentrations were 50μg/mL for Trichophyton mentagrophytes,100μg/mL for Microsporum canis and Trichophyton rubrum,and 200μg/mL for Microsporum gypseum.Gossypol inhibited the mRNA expression of metalloprotease(MEP4)and isocitrate lyase(ICL).The binding of gossypol with the enzymes was confirmed by molecular docking studies.The best docking poses were found and the low binding energies were recorded with the two target enzymes.Conclusions:Gossypol is a potential antifungal agent and can be further explored as an anti-dermatophytic drug.
文摘Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occurs, cytosolic sesquiterpenes are assumed to derive mainly from MVA, while plastidial monoterpenes are produced preferentially from MEP precursors. Additional complexity arises in the first step of the MEP pathway, which is typically catalyzed by two divergent 1-deoxy-D-xylulose 5-phosphate synthase isoforms （DXS1, DXS2）. In tomato （Solanum lycopersicum）, the SIDXS1 gene is ubiquitously expressed with highest levels during fruit ripening, whereas SIDXS2 transcripts are abundant in only few tissues, including young leaves, petals, and isolated trichomes. Specific down-regulation of SIDXS2 expression was performed by RNA interference in transgenic plants to investigate feedback mechanisms. SIDXS2 down-regulation led to a decrease in the monoterpene β-phellandrene and an increase in two sesquiterpenes in trichomes. Moreover, incorporation of MVA-derived precursors into residual monoterpenes and into sesquiterpenes was elevated as determined by comparison of ^13C to ^12C natural isotope ratios. A compensatory up-regulation of SIDXS1 was not observed. Down-regulated lines also exhibited increased trichome density and showed less damage by leaf-feeding Spodoptera littoralis caterpillars. The results reveal novel, non-redundant roles of DXS2 in modulating isoprenoid metabolism and a pronounced plasticity in isoprenoid precursor allocation.
