Structure-antioxidative activity relationships in benzylisoquinoline alkaloids.
نویسندگان
چکیده
The antioxidative properties of the aporphines boldine, glaucine and apomorphine, and of the benzyltetrahydroisoquinolines (+/-)-coclaurine and (+/-)-norarmepavine were compared in the brain homogenate autoxidation model. The IC50 values found lay in the 16-20 microM range for the aporphines and were 131.7 microM, and 79.3 microM for coclaurine and norarmepavine, respectively. These results indicate that the antioxidative capacity (AC) of these compounds is related to the presence of the biphenyl system rather than phenol groups. The non-phenolic glaucine inhibited the 2,2'-azobis-(2-amidinopropane)(AAP)-induced inactivation of lysozyme with an IC50 value of 12 microM, while the corresponding values for the phenolic coclaurine and norarmepavine were 10 and 20 microM, respectively. N-Methylation of glaucine to its quaternary ammonium reduced its protective effect by two-thirds. This result suggests that a benzylic hydrogen neighbouring a nitrogen lone electron pair may be the key to the protective effect of non-phenolic aporphines.
منابع مشابه
BIAdb: A curated database of benzylisoquinoline alkaloids
BACKGROUND Benzylisoquinoline is the structural backbone of many alkaloids with a wide variety of structures including papaverine, noscapine, codeine, morphine, apomorphine, berberine, protopine and tubocurarine. Many benzylisoquinoline alkaloids have been reported to show therapeutic properties and to act as novel medicines. Thus it is important to collect and compile benzylisoquinoline alkalo...
متن کاملA divergent approach to benzylisoquinoline-type and oxoaporphine alkaloids via regioselective direct ring metalation of alkoxy isoquinolines.
Methoxy- and benzyloxy-substituted isoquinolines are regioselectively metalated at C-1 with the Knochel-Hauser base, subsequent trapping with aromatic aldehydes gives aryl(isoquinolin-1-yl)carbinols as building blocks for divergent syntheses of different types of benzylisoquinoline alkaloids. Photochemical cyclization of ortho-bromo analogues under reductive conditions gives oxoaporphine alkalo...
متن کاملOverexpression of Coptis japonica norcoclaurine 6-O-methyltransferase overcomes the rate-limiting step in Benzylisoquinoline alkaloid biosynthesis in cultured Eschscholzia californica.
Benzylisoquinoline alkaloids are one of the most important secondary metabolite groups, and include the economically important analgesic morphine and the antimicrobial agent berberine. To improve the production of these alkaloids, we investigated the effect of the overexpression of putative rate-limiting step enzymes in benzylisoquinoline alkaloid biosynthesis. We introduced two O-methyltransfe...
متن کاملCytotoxic benzophenanthridine and benzylisoquinoline alkaloids from Argemone mexicana.
Fractionation of the chloroform extract from the aerial part of Argemone mexicana led to the isolation of two benzophenanthridine-type alkaloids, N-demethyloxysanguinarine and pancorine; three benzylisoquinoline-type alkaloids, (+)-1,2,3,4-tetrahydro-1-(2-hydroxymethyl-3,4-dimethoxyphenylmethyl)-6,7-methylenedioxyisoquinoline, (+)-higenamine and (+)-reticuline. Among them, N-demethyloxysanguina...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Pharmacological research
دوره 31 2 شماره
صفحات -
تاریخ انتشار 1995