Maytansine （I） (C34H46CIN3O10) is a novel type of ansa macrolide with potent antitumor activity. It was isolated by Kupchan et al. with great efforts from several Maytenus species （0.2 p.p.m.—1.5 p.p.m, dried plan...Maytansine （I） (C34H46CIN3O10) is a novel type of ansa macrolide with potent antitumor activity. It was isolated by Kupchan et al. with great efforts from several Maytenus species （0.2 p.p.m.—1.5 p.p.m, dried plant material） collected in Kenya and Ethiopia. It showed highly inhibitory activity against several experimental tumors （L-1210, P-388, W-256, S-180, Lewis lung carcinoma and B-16 melanocarcinoma） at the level of micrograms per kilogram body weight and the safety dosage ranging about 50—100 folds. Therefore, maytansine has been considered as one of the most promising anticancer agent of natural origin, attracting the interest of many relevant scientists.展开更多
It is well known that the SEA-TROSY experiment could alleviate some of the problems of resonance overlap in 15N/2H labeled proteins as it was designed to selectively map solvent exposed amide protons. However, SEA- TR...It is well known that the SEA-TROSY experiment could alleviate some of the problems of resonance overlap in 15N/2H labeled proteins as it was designed to selectively map solvent exposed amide protons. However, SEA- TROSY spectra may be contaminated with exchange-relayed NOE contributions from fast exchanged hydroxyl or amine protons and contributions from longitudinal relaxation. Also, perdeuteration of the protein sample is a pre-requisite for this experiment. In this communication, a modified version, clean SEA-TROSY, was proposed to eliminate these artifacts and to allow the experiment to be applied to protonated or partially deuterated proteins and protein complexes.展开更多
文摘Maytansine （I） (C34H46CIN3O10) is a novel type of ansa macrolide with potent antitumor activity. It was isolated by Kupchan et al. with great efforts from several Maytenus species （0.2 p.p.m.—1.5 p.p.m, dried plant material） collected in Kenya and Ethiopia. It showed highly inhibitory activity against several experimental tumors （L-1210, P-388, W-256, S-180, Lewis lung carcinoma and B-16 melanocarcinoma） at the level of micrograms per kilogram body weight and the safety dosage ranging about 50—100 folds. Therefore, maytansine has been considered as one of the most promising anticancer agent of natural origin, attracting the interest of many relevant scientists.
基金Project supported by the grants from One Hundred Talent Program of the Chinese Academy of Sciences and Shanghai Commission of Science and Technology (No. 03JC14081).
文摘It is well known that the SEA-TROSY experiment could alleviate some of the problems of resonance overlap in 15N/2H labeled proteins as it was designed to selectively map solvent exposed amide protons. However, SEA- TROSY spectra may be contaminated with exchange-relayed NOE contributions from fast exchanged hydroxyl or amine protons and contributions from longitudinal relaxation. Also, perdeuteration of the protein sample is a pre-requisite for this experiment. In this communication, a modified version, clean SEA-TROSY, was proposed to eliminate these artifacts and to allow the experiment to be applied to protonated or partially deuterated proteins and protein complexes.
