Alkaloids ofDelphinium speciosum
On separating the total alkaloids we isolated methyllycaconitine, lycoctonine, anthranoyllycoctonine, and gigactonine, which were identified on the basis of an analysis of spectral characteristics and a comparison of the I~C NMR spectra. In addition to these, a base was isolated with mp 180-182°C (acetone), composition C22H35N05 (I). The NMR spectrum of (I) had the signals of tertiary C-methyl group (0.97 ppm, 3 H, singlet), of a N-ethyl group (1.04 ppm, 3 H, triplet, J = 7 Hz), and of a methoxy group (3.82 ppm, 3 H, singlet), and also one-proton signals at 4.12 ppm (triplet, J = 5 Hz) and 4.6 ppm (doublet, J = 7 Hz), The IR spectrum showed the absorption bands of hydroxy groups at 3400-3600 cm -: and of ether bonds at ii00 cm -~. The mass spectrum of (I) was characteristic for alkaloids with the lycoctonine skeleton and was close to the spectrum of karakoline [2, 3]. The maximum peak in the mass spectrum of (I) was the peak of the M +17 ion, showing the presence of the hydroxy group at C-I [2], Acetylation of the alkaloid with acetic anhydride in the presence of pyridine yielded the triacetate (II) with mp 162-164°C (acetone), showing the presence of three secondary hydroxy groups. Its mass spectrum contained the peak of the molecular ion M + 519 (8%), and also the peaks of ions with m/z 476 (8%), 460 (100%), 416 (15%) and 400 (12%), The PMR spectrum contained the signals of a N-ethyl, a tertiary C-methyl, and of three acetoxy groups, and also one-proton signals at 4.68 ppm (triplet, J = 5 Hz), 4.75 ppm (quartet, ABX system, JAX = i0 Hz, JBX = 7 Hz) and 5.22 ppm (doublet, J = 7 Hz), showing the presence of hydroxy groups at C-14, C-I, and C-6 [3, 4]. The acetylation of (I) with acetyl chloride gave the tetraacetate (III). Its mass spectra contained the peak of the molecular ion M + 561 (1%), and also the peaks of ions with m/z 502 (77%), 442 (33%), 400 (100%), and 372 (33%), According to these results, the fourth hydroxy group must be located at C-8, The information obtained indicated that (I) was alkaloid B, isolated previously from Delphinium bicolor Nutt, [4-7]. A direct comparison with alkaloid B kindly supplied by Prof, M. N, Benn showed their identity.
The alkaloids of nutt.
The structures of alkaloid- and - were established via X-ray crystallography of the former as its HI salt, and its chemical conversion to the latter.
Full-scale measurements of SO2 gas phase concentrations and slurry compositions in a wet flue gas desulphurisation spray absorber
Abstract Two measurement campaigns were carried out at ENERGI E2's Asnaes Power plant, unit 5. The unit has a capacity of 620 MW e and is equipped with a wet flue gas desulphurisation (FGD) plant employing a counter-current spray absorber with five spray levels. In the first campaign, the power plant was firing Orimulsion ® with 2.85 wt% S resulting in a flue gas concentration of SO 2 exceeding 2000 ppmv. In the second campaign, the fuel applied was a low-S blended coal and the SO 2 concentration in the raw gas was around 400 ppmv. A novel probe for in situ sampling of gas phase concentrations in wet FGD spray absorbers was developed and applied for measuring axial profiles of the SO 2 gas phase concentrations in the absorber. The expected decrease in SO 2 concentrations along the height of the absorber was found in the spray section (from height 26.5 to 36.2 m) whereas the SO 2 concentration above the holding tank and below the gas inlet was quite low probably due to long local residence times in the region. Horizontal variations, due to somewhat different flow conditions near the column wall were investigated and the SO 2 concentrations were found to be higher near the wall. Measurements at different gross loads showed that the SO 2 gas phase concentration at a given position inside the absorber was roughly linearly related to the L/G ratio in the measuring interval. Turning off one of the lower spray levels, while burning coal with low S content, did not lower the overall removal efficiency of the absorber. However, the SO 2 gas phase concentration inside the lower part of the absorber was increased by a factor of 2–3. Measurements of slurry pH at different positions showed a decrease of approximately 0.5 units from the upper to the lower part of the absorber. The full-scale measurements provide a detailed set of experimental data for validation of mathematical models of a wet FGD spray absorber.