6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones（6-DMNQ）,the promising anticancer scaffolds,were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H...6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones（6-DMNQ）,the promising anticancer scaffolds,were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H2O in comparatively high yields.An interesting finding was that apart from the reported electron-withdrawing effects of substituents on position 2 of naphthalene ring,regioselective synthesis of 6-DMNQ was largely dependent on the steric effects in CAN-mediated oxidation.The selective cytotoxicities of 6-DMNQ from the in vitro cell-based assays were exhibited between the cancer cells and normal cells.Moreover,most of sulfur-containing 6-DMNQ derivatives displayed better anticancer activities than the corresponding oxygen-containing ones,which could provide an available strategy for the design of 6-DMNQ derivatives as potential anticancer agents.展开更多
A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding,named brainin A（1）,was isolated from the rhizomes of Brainea insignis.Its structure was elucidated on the basis of spectral data incl...A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding,named brainin A（1）,was isolated from the rhizomes of Brainea insignis.Its structure was elucidated on the basis of spectral data including 2D NMR and HR-ESI-MS.展开更多
Two new flavanol derivatives, bearing phenylpropionic acid moiety at C-4 through a C--C bonding, named brainin B （1） and brainin C （2）, were isolated from Brainea insignis. Their structures were elucidated by NMR ...Two new flavanol derivatives, bearing phenylpropionic acid moiety at C-4 through a C--C bonding, named brainin B （1） and brainin C （2）, were isolated from Brainea insignis. Their structures were elucidated by NMR and MS spectrometry, Brainins B and C were tested for their antioxidant properties in DPPH （2,2-diphenyl-l-picryl- hydrazyl） radical scavenging, and both compounds displayed potent antioxidant activities.展开更多
基金supported by National Natural Science Foundation of China(No.81373274)Ph.D.Programs Foundation of Ministry of Education China(No.20120073110068)Shanghai Biomedical Supporting Funding(No.15431900600)
文摘6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones（6-DMNQ）,the promising anticancer scaffolds,were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H2O in comparatively high yields.An interesting finding was that apart from the reported electron-withdrawing effects of substituents on position 2 of naphthalene ring,regioselective synthesis of 6-DMNQ was largely dependent on the steric effects in CAN-mediated oxidation.The selective cytotoxicities of 6-DMNQ from the in vitro cell-based assays were exhibited between the cancer cells and normal cells.Moreover,most of sulfur-containing 6-DMNQ derivatives displayed better anticancer activities than the corresponding oxygen-containing ones,which could provide an available strategy for the design of 6-DMNQ derivatives as potential anticancer agents.
基金supported by the Natural Science Foundation of China(Nos.30560178 and 20964005)by a program for New Century Excellent Talents in University from MOE(No.NCET-08-0925)a grant from Education Department of Yunnan Province(No.08Y10302)
文摘A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding,named brainin A（1）,was isolated from the rhizomes of Brainea insignis.Its structure was elucidated on the basis of spectral data including 2D NMR and HR-ESI-MS.
文摘Two new flavanol derivatives, bearing phenylpropionic acid moiety at C-4 through a C--C bonding, named brainin B （1） and brainin C （2）, were isolated from Brainea insignis. Their structures were elucidated by NMR and MS spectrometry, Brainins B and C were tested for their antioxidant properties in DPPH （2,2-diphenyl-l-picryl- hydrazyl） radical scavenging, and both compounds displayed potent antioxidant activities.
