Anne Fiksdahl

High-pressured liquid chromatography of carotenoids

Abstract The potential of high-pressure liquid chromatography (HPLC) for separation of carotenoids on silica has been studied with selected model carotenoids (carotenes, diols, cis—trans isomers and diastereoisomers) in comparison with conventional thin-layer chromatography and circular paper techniques. Fast and efficient separation on the analytical scale was obtained, including that of epimers not previously separated. The advantage of HPLC coupled with a UV—VIS scanning spectrophotometer for the analysis of cis—trans isomerization mixtures of carotenoids is pointed out.

Carotenoids of the chrysophyceae

Abstract 1. 1. The carotenoids of seven selected chrysophycean algae (Ochromonas sp., Poterioochromonas malhamensis, Olisthodiscus luteus (two strains), Synura petersenii, Chromulina ochromonoides and Sarcinochrysis marina ) were analysed quantitatively and identified by methods including mass spectrometry. 2. 2. β,β-Carotene was invariably present. The allenic fucoxanthin was always the major carotenoid, occasionally accompanied by small amounts of its desacetyl derivative, fucoxanthinol, and the allenic epoxide neoxanthin. 3. 3. Common accessory carotenoids comprised zeaxanthin, its monoepoxide antheraxanthin (one source only) and its diepoxide violaxanthin. Sarcinochrysis marina , also a chrysophyte ( sensu-stricto ) differed from this pattern in that the minor accessory carotenoids occurring with fucoxanthin and β,β-carotene were the acetylenic diatoxanthin and diadinoxanthin, which are typical prymnesiophyte carotenoids. 4. 4. It is concluded that the Chrysophyceae have a rather characteristic carotenoid pattern different from that of many algal classes. However, a distinct separation of the Chrysophyceae from the Prymnesiophyceae on the basis of carotenoid composition is not always possible.

Algal carotenoids with novel end groups

Abstract The structures of three previously unidentified carotenoids from Eutreptiella gymnastica are reported. These include siphonein with defined n -2- trans -2-dodecenoic esterifying acid and assigned 3 R (?), 3′ R ,6′ R chirality, (3 R )-3′,4′-anhydrodiatoxanthin and eutreptiellanone (3,6-epoxy-3′,4′,7′,8′-tetradehydro-5,6-dihydro-β,β-caroten-4-one) with probable 3 S ,5 R ,6 S chirality.

Carotenoids of the Raphidophyceae: a chemosystematic contribution

Abstract 1. 1. The carotenoids in two members of the Raphidophyceae (chloromonads) Gonyostomum semen and Vacuolaria virescens , and of two tentative members of this class Chattonella japonica and Fibrocapsa japonica were analyzed quantitatively and identified by methods including mass spectrometry and chemical derivatizations. 2. 2. Group I ( G. semen and V. virescens ) showed a similar carotenoid pattern, comprised of diadinoxanthin (54–60% of total carotenoid), dinoxanthin (8–17%), β,β-carotene (7%) and heteroxanthin (7%), as well as neoxanthin (G. semen , 3%), an epoxidic monoacetate ( G. semen , 12%), an epoxidic carotenol = 9′- cis -diadinoxanthin? ( V. virescens , 8%), an epoxidic diacetate ( V. virescens , 2%) and vaucheriaxanthin 3,19-diacetate ( V. virescens , 8%). Both chlorophyll c forms ( c 1 and c 2 ) were detected in V. virescens ; ratio a / c 1 + c 2 , 20:1. This pigment composition resembles that of the Xanthophyceae. 3. 3. Group II ( Chattonella japonica and Fibrocapsa japonica ) exhibited a different carotenoid pattern with fucoxanthin (40–68%), fucoxanthinol (3–42%), β,β-carotene (15–27%) and violaxanthin (1–2%) in common. C. japonica also contained zeaxanthin (1%). This carotenoid pattern resembles that of Chrysophyceae. 4. 4. Characteristic features common to the carotenoids encountered are a high proportion of epoxidic carotenoids (78–86%), allenic carotenoids (24–82%), acetylated carotenols (18–81%) and acetylenic carotenoids (61–67%; Group I only). 5. 5. A scheme for the carotenoid biosynthesis that could lead to both observed patterns is proposed. The present analyses require a revision of phylogenetic schemes based on the photosynthetic pigments.

Diacetylenic carotenoids from Euglena viridis

Abstract Quantitative carotenoid analysis revealed the presence of β,β-carotene ( ca 5% of total carotenoid) mixed with some β,e-carotene, the β,e-carotene derived siphonein (siphonaxanthin 19-dodecenoate, 8%), the allenic neoxanthin (4%) and acetylenic carotenoids > 86% of total carotenoids. These were the monoacetylenic diatoxanthin (major, 61%), diadinoxanthin (rearranged to diadinochrome, 12%), heteroxanthin (1%) and the new diacetylenic 3,4,7,8,3′,4′,7′,8′-octadehydro-β,β-carotene (6%) and esterified 7,8,3′,4′,7′,8′-hexadehydro-β,β-caroten-3-ol (6%). The methods employed included TLC, HPLC, Vis, 1 H NMR (400 MHz) and MS. The significance of the presence of siphonein and diacetylenic carotenoids for algal chemosystematics is briefly discussed.

Nucleophilic substitution of chiral amine N,N-ditosylderivatives

Abstract The chiral transformation of the optically active amine 10 to the corresponding alcohol 2 with opposite configuration is reported. The transformation is carried out via an S N 2 type reaction of the N , N -ditosylimide, -NTs 2 , by nucleophilic attack of the hydroxide, acetate or benzoate ion to give an inversion degree of 85–100%. 0–34% stereoselectivity was obtained in the corresponding chloride nucleophilic substitutions. Separation parameters for the chromatographic enantioseparations of the amines 10–12 , the chlorides 4,7,9 and the alcohol 2 using a chemically bonded cyclodextrin GLC column are discussed.

Carotenoids of Heterosigma akashiwo: A chemosystematic contribution

Abstract The presence of C 37 -norcarotenoids (peridinin and probably pyrrhoxanthin, together 87% of total carotenoids) and the carotenoid pattern in general, including dinoxanthin, diatoxanthin and β,β-carotene, but no fucoxanthin, strongly suggest that H. akashiwo is a dinoflagellate and not a chrysophyte.

Carotenoids of blue-green algae—11. carotenoids of chromatically-adapted cyanobacteria

Abstract 1. 1. The total carotenoid content and carotenoid composition of a Lyngbya-Plectonema-Phormidium (L.P.P.) sp., Fremyella diplosiphon and Tolypothrix tenuis grown in semicontinuous culture in white light or red light ( >590 nm ) are reported. 2. 2. Complementary chromatic adaptation of these cyanobacteria is manifested by changes in phycobiliprotein synthesis and also effected the carotenoid synthesis. 3. 3. The total carotenoid content of L.P.P. sp. nearly doubled with a selective increase in the concentrations of β,β-carotene and zeaxanthin when the cells were grown in red light compared with white light. 4. 4. F. diplosiphon showed a 45% and T. tenuis a 21% reduction in total carotenoids with no significant selective effect on individual carotenoids, including ketonic and glycosidic types, under the same illumination conditions. 5. 5. There is apparently a direct relationship between total carotenoid content and phycobilisome size for L.P.P. sp. and F. diplosiphon , which may be associated with the protective effect of carotenoids against photosensitized oxidation. 6. 6. The Kezar Lake strain of Aphanizomenon flos-aquae (white light only) differed in carotenoid composition with previous results.

Nor-carotenoids from Sea Anemones☆

Abstract The quantitative carotenoid composition of A. equina and A. tenebrosa is compared. A closer examination of the minor carotenoids has been carried out. Actinioerythrol and its monoester are new, naturally occurring 2,2-dinor-carotenoids.