Alkaloids ofThalictrum collinum
The method of methanolic extraction was applied to the roots. After the methanol has been distilled off, the concentrated extract was treated with 10% sulfuric acid, the acid extracts were alkalinized to pH 9, and the alkaloids were extracted with ether and chloroform. The combined ether-soluble and chloroform-soluble alkaloids obtained were separated into phenolic and nonphenolic bases. The combined nonphenolic tertiary bases were chromat.graphed on a column of alumina (1:70, neutral, activity grade II). The alkaloids were eluted with benzene, benzene--chloroform, chloroform, ethyl acetate, and ethyl acetate-methanol.
Thalictrum alkaloids. V. Isolation.
The experimental procedure which led to the isolation of the new alkaloids thalifendlerine (I), thalifendine (II), thalidastine (III), thaliporphine (IV), preocoteine (V), and thalidezine (VI), from Thalictrum fendleri is described in detail. Known alkaloids also found in T. fendleri are berberine (VII), jatrorrhizine (VIII), glaucine (IX), magnoflorine (X), ocoteine (XI), hernandezine (XII), and thalicarpine (XIII). A completely new dimeric aporphinebenzylisoquinoline alkaloid of only partially elucidated structure is thaldimenne (XIV). A novel procedure for the separation of tertiary alkaloids consists of partition chromatography of the mixture of hydrochloride salts using a cellulose column in the system methyl ethyl ketone–water.
Interaction of Diclofop-Methyl and MCPA on Wild Oats (Avena fatua)
Diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate} loses part of its activity on wild oats (Avena fatua L.) when it is applied in combination with ester or amine formulations of MCPA {[4-chloro-o-tolyl)oxy] acetic acid.} Uptake of diclofop-methyl is reduced in the presence of commercial formulations of MCPA, particularly amine formulations, which are only partly compatible with the diclofop-methyl formulation. With added MCPA, regardless of formulation, hydrolysis of diclofop-methyl to the acid diclofop is slowed down, both in intact wild oat plants and in a crude leaf extract. At the same time, conversion of any acid formed to inactive conjugates is accelerated in the presence of MCPA. It is concluded that the loss of activity of diclofop-methyl by MCPA can be accounted for by the effects of MCPA on uptake and metabolic conversion of diclofop-methyl.