2,3,7-Trimethcxy-8,9-methylenedioxypavinan — A new alkaloid from Thalictrum strictum. II
F rom the epigeal pa r t of Th. s t r i c tum we have i so la ted a new unidentified base B (I). The alkaloid (I) is readi ly soluble in methanol , ethanol, and acetone and when the solvents are evapora ted it s epa ra t e s out in the fo rm of a faint yellowish oil . After chromatography twice on a column of a lumina and concentrat ion of the e therea l eluate, compound (I) c rys ta l l i zed in the fo rm of t r anspa ren t p r i s m s with mp 144-145°C, [o~]~ 1 7 4 ° (c 0.977; methanol).
THE ALKALOIDS OF PAPAVERACEOUS PLANTS: LIV. THE STRUCTURE OF ESCHSCHOLTZINE
Eschscholtzine, a new alkaloid from Eschscholtzia californica, has been shown to be the bismethylenedioxy analogue of N-methylpavine (argemonine). The mass spectrometric fragmentation of alkaloids of the pavine type is discussed.
Increasing pulp yield in kraft cooking of softwoods by high initial effective alkali concentration (HIEAC) during impregnation leading to decreasing secondary peeling of cellulose
Abstract Pulp yield can be improved by a more homogeneous delignification of the chips, achieved by improved impregnation prior to the cooking stage. Complete and efficient impregnation is obtained by increasing the diffusion rate by means of an impregnation liquor with a high initial effective alkali concentration (HIEAC). In the present study, the effect of HIEAC in the impregnation was evaluated and compared to a reference impregnation procedure and a prolonged impregnation. After the various impregnation scenarios, the alkali concentration was always adjusted to the same level in the beginning of the cooking stage. Impregnation with a HIEAC resulted in yield improvements by 1–1.5% units, due to a higher cellulose yield and possibly also to higher yield of glucomannan. The HIEAC with an even alkali distribution within the chips prior to the cooking stage resulted in a more uniform delignification carbohydrate degradation. Yield increase obtained by uniform delignification is due to both decreased shives content as well as less secondary peeling.