Sporopollenin obtained from wings of Pinus mugo (Turra) pollen was analysed by pyrolysis mass spectrometry. In the spectrum, mass peaks which are characteristic for p-coumaric acid were dominant. p-Coumaric acid was the main degradation compound when the wing material was treated by a gentle method using AII3, and also when the remaining residue of the treated sporopollenin material was saponified. It is therefore assumed that p-coumaric acid is a genuine structural unit in the sporopollenin skeleton. In addition, the effects of AII3 treatment indicate that the p-coumaric acid might be bound by ether linkages.

147ness after blue light (not shown). This shows that energy and metabolites were not completely absent. However, as hair-whorl formation was undetectable (with the exception of dwl), this could mean that the transition to the development of whorls only proceeded when the level of photosynthetic metabolites was higher than the minimum required for stalk growth alone. The different requirements for red irradiation among the different strains would then reflect different levels of metabolite availability. Similar differences in the light requirement for stalk growth and cap formation were observed with Acetabularia erenulata grown in white light of various irradiances (Terborgh and Thimann 1965).The metabolites must be available and produced at the tip itself since local irradiation of Acetabularia cells has shown that growth can proceed only when the cells receive light at the apex rather than at the base (Gibor 1977). Apical or basal applications of DCMU also prevented growth only when the tip was treated, indicating that at least part of these effects were due to photosynthesis. Metabolites and DCMU do not appear to be transported longitudinally.References Clauss, H. (1968) Planta (1989) 179:376-380 Page 377: The intensity of m/z 164 indicates that the compound is bound by its acid group in the sample because ester-bound p-coumaric acid decarboxylates during pyrolysis to vinylphenol (Boon 1989).The corrected text: The intensity of m/z 164 indicates that the compound is not bound by its acid group in the sample because ester-bound p-coumaric acid decarboxylates during pyrolysis to vinylphenol (Boon 1989).

To confirm findings obtained from animal experiments demonstrating the metabolic effect of two new glucosidase inhibitors, 7 single blind cross-over studies with 42 healthy male volunteers were performed. In each group 6 subjects received 25, 50, 100 and 200 mg BAY m 1099 and 10, 20, and 40 mg BAY o 1248 or placebo with a standardized breakfast. Blood glucose and serum insulin were measured in venous blood before and 30, 60, 90, 120 and 180 min after each of 3 meals. ECG, blood pressure, body weight, monitor ECG and haematological and clinico-chemical parameters were also examined. The postprandial increase in blood glucose and serum insulin after breakfast were significantly and dose-dependently reduced by BAY m 1099. 10 and 20 mg BAY o 1248 not only reduced the increases in blood glucose and serum insulin after breakfast, but also after lunch (10 mg). 40 mg BAY o 1248 prevented the postprandial increase in both metabolic parameters after breakfast (p less than 0.05), an effect which was sustained after lunch. Intestinal problems occurred (flatulence, meteorism, diarrhoea) in 25 of 42 volunteers. Objective tolerability was good. The results of these first clinical pharmacological studies with two new glucosidase inhibitors justify studies on patients with diabetes mellitus.

An approach is described for evaluation of the specificity of basic polypeptides concerning the base pair composition of DNA. The polypeptides were covalently bound to CNBr activated agarose and two DNAs strongly different in base composition but of equal molecular weight were loaded and detached by a NaCl gradient. The difference in the NaCl concerntrations between the elution maxima of the two DNAs was taken as a measure for the recognition specificity. The results obtained confirmed the known AT- und GC-specificity of polylysine and polyarginine, respectively. Neutral residues incorporated into polylysine generally reduce the interaction affinity and also the AT-specificity of their host. This behavior is very pronounced with three homogeneous fractions of clupeine containing about one third of neutral aliphatic amino acids within clusters of arginine; the base pair specificity of these arginine copolymers was found to be practically nil.

The alpha-amino group of clupeine fraction Z from herring sperm was coupled with fluorescein. Binding of the labeled protamine by DNA is accompanied by significant fluorescence quenching up to 80%. This allowed the convenient determination of the binding behavior of protamine and DNA. Binding was found to be strongly cooperative and not be significantly affected by the size of DNA. The ionic strength dependence in the range up to 0.3 M NaCl was rather small. Binding parameters were derived according to classical unique-site treatment and to a concept which includes vagrant multi-site binding.