Carotenoid cleavage enzymes have been investigated for more than 50 years. Nevertheless, progress in this area has been slow and a complete understanding of the reaction mechanisms of carotenoid biodegradation has not been achieved at the present time. In this study, the enzymatic cleavage of carotenoids in several insect species (Calliphora, Ornithoptera, and Locusta) is examined. The enzymatic degradation of carotenoids in plants is also elucidated. Quince (Cydonia oblonga) and star fruit (Averrhoa carambola) were examined in detail, since both fruit are known to contain major amounts of carotenoid derived C 13 norisoprenoid aroma compounds. Our data demonstrates that carotenoid cleavage enzymes purified from animal tissues are similar to each other, whereas carotenoid cleavage enzymes obtained from fruit are clearly different and readily distinguished.The first report concerning carotenoid cleavage enzymes was published 60 years ago (/). However, knowledge about kinetic properties, protein structure and reaction mechanisms of carotenases has progressed slowly in the ensuing 76

Treatment of canthaxanthin (beta,beta-carotene-4,4'-dione) (1) with nickel peroxide in dichloromethane yielded a series of cleavage products, i.e., 4-oxo-beta-ionone (2), (7E, 9E)-4-oxo-beta-apo-11-carotenal (3a), (7E, 9Z)-4-oxo-beta-apo-11-carotenal (3b), 4-oxo-beta-apo-13-carotenone (4), 4-oxo-beta-apo-14'-carotenal (5), 4-oxo-beta-apo-12'-carotenal (6), and 4-oxo-beta-apo-10'-carotenal (7). In addition, oxidized canthaxanthin derivatives, i.e., isomeric ketols all-trans-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8a), (9'Z)-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8b), and (13'Z)-9, 10-dihydro-9-hydroxy-10-oxo-canthaxanthin (8c) were obtained together with the tentatively identified (9'Z)-canthaxanthin-20-al (9). Structure elucidation of the reaction products was achieved by mass spectrometry and two-dimensional NMR spectroscopy.

During mating male bushcrickets transfer large spermatophores, which have been demonstrated to play an important role in female nutrition and egg production. Until now only relatively unspeci¢c substances such as water and proteins were known to be present within these spermatophores. We found that in the bushcricket Ephipp iger zelleri the spermatophores contain substantial amounts of carotenoids (mainly lutein and zeaxanthin) that are also found in the eggs of this species. Carotenoids are well known for their positive e¡ects on survival and reproduction in animals. This is the ¢rst example, to our knowledge, where such speci¢c vitamin-like substances were found to be transferred from male to female during mating.

In Arnica montana L. (Asteraceae) two subspecies are described, A. montana subsp. atlantica (AMA), present only on the Iberian Peninsula and A. montana subsp. montana (AMM) with a very wide distribution area. The morphological differences between the two subspecies are small and variable. Therefore, this concept is sometimes questioned. To establish the genetic background of the two subspecies, populations of AMA and AMM together with herbarium samples and DNA Bank material of AMM were tested with 12 microsatellite markers. A. montana propagates by seeds or by clonal propagation of its rhizome. In AMA, clonality was frequent while in AMM only one case of clonality could be identified. Therefore, further results were clone-corrected. Genetically, AMA separated very well from AMM with a G ST between the subspecies of 0.81, genetically justifying the subspecies concept of A. montana. Genetic variability in AMA (H exp =0.28) was lower than in the AMM populations (H exp =0.70). A somewhat higher fixation index of AMA (F ST = 0.17, compared to an F ST =0.08 for AMM) may indicate that geneflow in AMA is a bit more restricted than in alpine AMM. However, the fixation index of AMA is not deviating from Hardy-Weinberg equilibrium. No inbreeding was observed for AMA (F IS = 0.10) and AMM (F IS =0.08).

The 9-O-beta-D-glucopyranosides of (6R)-3-oxo-4-hydroxy-7,8-dihydro-alpha-ionol 1 and 3-oxo-5,6-epoxy-beta-ionol 2 were isolated from quince leaves. The glycosidic extract was obtained by XAD-2 adsorption and MeOH elution. After DCCC separation and flash chromatography, purification by high performance liquid chromatography was carried out. The novel quince leaf constituents were characterized as peracetates 1a and 2a.