ABSTRACT
Table 3.1 The absorbance and fluorescence maxima (nm) of sesquiterpene lactones and its derivatives (excitation by light 360 nm) solved in 96% ethanol
Artemisinine 298 395, shoulder 430 Austria ne 256, 350 406 Azulene commercial 580 420 Deacetylinulicine 208-212, 225-230 446 Gaillardine 208 415-420 Gelenine 220, shoulder 285 420 Grosshemine 256, 338 400 Inulicine 208(220), shoulder 270 400, shoulder 440 Ledol 200-210 400-408, shoulder 460 Santonine 240-250, shoulder 270 408, 450 Taurine 200 440 Tauremisine 200, 295 406, shoulder430
As seen from the illustrations, many sesquiterpene lactones fluoresce in the blue spectral region which is characteristic for terpenoids as a whole. Main maxima were at 406-440 nm depending on the chemical nature of sesquiterpene lactone. Substances related to the guajacol group such as gaillardine has only one maximum in blue, whereas inulicine from psilostachanas - also the shoulder. The maximum and shoulder are characteristic for artemisinine and tauremisine. Azulene fractions extracted from pollen loads (Roshchina et al., 1995) or from vegetative microspores of Equisetum arvense (Roshchina et al., 2002) fluoresce with maxima 438456 nm and 420 nm, relatively, whereas commercial azulene - at 420 nm. The fluorescence could be also associated with the presence of y-lactone as fluorophore in the molecules. Metals stimulate it (Zhang et al., 2006).
