A new class of carotenoids

The pigments of some further marine phytoplankton species

“…The major xanthophyll, which constituted 75-90% of the total xanthophylls was designated 'alloxanthin' and the two minor ones were named 'monodoxa: rin' and 'crocoxanthin'. Subsequent investigations (Mallams et al, 1967) have demonstrated that alloxanthin is a di-acetylenic analogue of zeaxanthin, and that the minor pigments are related monoacetylenic compounds. Work completed in these laboratories on the xanthophylls of a further 4 species from this order, prior to the publication of the paper by Chapman (1966), indicated (Riley & Wilson, 1967) the presence of * This compound was designated diatoxanthin by Allen et al (1964) and 'probably zeaxanthin' by Haxo & Fork (1959), but it is almost certainly alloxanthin I.…”

Photosynthetic Pigments of Symbiotic Dinoflagellates (Zooxanthellae) From Corals and Clams

“…However, identity of the former as cryptomonads from morphological evidence could not be excluded at the time. Subsequent biochemical analyses of cryptomonads by Haxo and Fork (1959) and Mallams et al (1967) showed that these algae possess a unique com-1 Most of the experimental work described in this paper was carried out on board the University of California research vessel, R/V "Alpha Helix," in Princess Charlotte Bay, North Queensland, Australia from July to September, 1966. The Expedition was supported by the U. S. A.…”

Some recent advances in the synthesis of carotenoids

“…evidence9. i,CO2H [14] 1171 [181 [L]+Ph3PCO2Me - [19] CO2 Me 1201 Zechmeister'°has suggested that the unstable cis-isomer of crocetin, isolated as the dimethyl ester by Kuhn and Winterstein'1, has the corresponding cis-2 structure [23]. We found 12 that reaction of the pentaenedial [21113 with the phosphonate derived from oc-bromopropionate gave a mixture of all-trans-and cis-2 methyl crocetin [22] and [23].…”

“…Reduction of its acid chloride with lithium tri-t-butoxyaluminohydride led to the corresponding aldehyde [18] with complete retention of stereochemistry. Reaction of the aldehyde [18] with the Wittig reagent [19], which was prepared from the Cio-dial [4], then yielded the cis-4 isomer of methylbixin [20] which proved to be identical in all respects with the methyl ester of natural bixin8. This synthesis confirms the stereochemistry assigned to methyl natural bixin on n.m.r.…”