Analysis of the non-polar fraction of giant ragweed pollen: Carotenoids

Survey of Pollen and Pollenkitt Lipids–chemical Cues to Flower Visitors?

“…Pollenkitt was distinguished from the internal pollen fraction by the detection of hydrocarbons, carotenoid pigments, and larger -8 --numbers of terpenoids (as acids, alcohols, aldehydes, ketones, and esters). Similar lipid classes have been reported in the few previous studies of pollenkitt and anther oils (Wittgenstein and Sawicki, 1970;Egorov and Egofarova, 1971;Dumas, 1977). The high frequency of these nonglyceride lipids suggests that pollenkitt may be the carrier of pollen aroma, and possible parallels may be drawn between the kinds of oils found in pollenkitt and those reported for floral fragrances (Williams, 1983;Harborne and Turner, 1984).…”

“…As the repository of pollen carotenoids, pollenkitt may provide important visual cues to flower visitors. In a survey of pollen pigments from 66 species, Lubliner-Mianowska (1955) found carotenoids to occur primarily in insectpollinated plants; carotenoids have, however, been found in some anemophilous species as well (Wittgenstein and Sawicki, 1970;Wiermann and Vieth, 1983). Detection of flavonoids in pollenkitt of several species supports evidence that these pigments may occasionally be deposited along with or underneath the pollenkitt (Wiermann and Vieth, 1983), in which case low-polarity flavonoids are more probably involved than the common glycosides (Wiermann, 1968;Stanley and Linskens, 1974;Pontovich, Prokhorchik, and Volynets, 1984).…”

“…Neutral lipids in pollen may include glycerides, free fatty acids, sterols, sterol esters, hydrocarbons, and nonsterol terpenoids, as well as carotenoid pigments (e.g., Heslop-Harrison, 1968;Stanley and Linskens, 1974;Opute, 1975Opute, , 1978Larian ova et al, 1977;Roberts, Stead, and Dickinson, 1979). Studies focused on the pollenkitt of Ambrosia (Wittgenstein and Sawicki, 1970) and Vitis (Egorov and Egofarova, 1971) and the tapetum of Forsythia (Dumas, 1977) have shown lipid diversities similar to those commonly found in plant essential oils . Carboxylated polysaccharides have been reported in pollenkitt ofCompositae (Klungness and Peng, 1984) , and small quantities of proteins and glycoproteins, thought to participate in pollenpistil incompatibility reactions, in exine-deposited materials of several species (Knox and Heslop-Harrison, 1970;Clarke et al , 1979;Knox, 1984).…”

Chemistry of Biologically Important Synthetic Organoselenium Compounds

“…The first natural carotenoid lutein ( 435 , Figure ) was discovered in 1837 by Berzelius, who also discovered selenium in 1818 . The strong link between selenium and carotenoids was first realized when selenium and carotenoids were found together in certain plants − and algae . Studies on biological functions and activities of natural carotenoids have been mainly performed in the fields of photosynthetic plants, algae, and bacteria, and two major functions have been revealed: (i) a light harvesting role in the antenna complexes of the chloroplast in photosynthesis and (ii) as protecting agents against the harmful photooxidative effects of bright light .…”

Haptenic Side Chains as Posttranslational IgE-Binding Determinants among Pollen Protein Allergens

“…Scarce attention has so far been given to the idea that pollen proteins may owe their allergenicity to low-molec ular-weight compounds of defined chemical structure asso ciated as haptenic side chains to carrier proteins [1,2]. Such IgE-or IgG-binding antigenic determinants might derive from pro-hapten precursors (e.g.…”