Carotenoids in marine invertebrates living along the Kuroshio current coast.

Carotenoids of the corals Acropora japonica, A. secale, and A. hyacinthus, the tridacnid clam Tridacna squamosa, the crown-of-thorns starfish Acanthaster planci, and the small sea snail Drupella fragum were investigated. The corals and the tridacnid clam are filter feeders and are associated with symbiotic zooxanthellae. Peridinin and pyrrhoxanthin, which originated from symbiotic zooxanthellae, were found to be major carotenoids in corals and the tridacnid clam. The crown-of-thorns starfish and the sea snail D. fragum are carnivorous and mainly feed on corals. Peridinin-3-acyl esters were major carotenoids in the sea snail D. fragum. On the other hand, ketocarotenoids such as 7,8-didehydroastaxanthin and astaxanthin were major carotenoids in the crown-of-thorns starfish. Carotenoids found in these marine animals closely reflected not only their metabolism but also their food chains.

Structures of minor carotenoids from the Japanese common catfish, Silurus asotus.

Three new carotenoids: 7',8',9',10'-tetrahydro-ß-cryptoxanthin, 7',8'-dihydrodiatoxanthin, and (3S,6S,6'S)-ε-cryptoxanthin were isolated from the skin, fins, and gonads of the Japanese common catfish, Silurus asotus, as minor carotenoids. Their structures were determined based on chemical and spectroscopic data. Furthermore, 9Z and/or 9'Z geometrical isomers of parasiloxanthin, 7',8'-dihydroparasiloxanthin, and 7',8'-dihydro-ß-cryptoxanthin were characterized by (1)H-NMR.

MassBank: a public repository for sharing mass spectral data for life sciences.

MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron-ionization mass spectrometry (EI-MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)-MS(n) data of 2337 authentic compounds of metabolites, 11 545 EI-MS and 834 other-MS data of 10,286 volatile natural and synthetic compounds, and 3045 ESI-MS(2) data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI-MS(2) data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass-to-charge ratio are optimized to the ESI-MS(2) data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI-MS(2) data on an identical compound under different collision-induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21-23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data.

Carotenoids in clams, Ruditapes philippinarum and Meretrix petechialis.

Carotenoids were investigated in two species of clams, Rudiapes philippinarum and Meretrix petechialis. Fucoxanthin 3-esters and fucoxanthinol 3-esters were found to be major components, along with crassostreaxanthin A 3-acetate, crassostreaxanthin A, crassostreaxanthin B 3-acetate, crassostreaxanthin B, halocynthiaxanthin 3'-acetate, halocynthiaxanthin, alloxanthin, diatoxanthin, diadinoxanthin, and heteroxanthin. Fatty acids esterified with fucoxanthin and fucoxanthinol were identified as C24:6, C22:5, C22:6, C20:5, C20:0, C20:1, C18:0, C18:1, C16:0, C16:1, and C14:0 from fast atom bombardment-mass spectrometry (FAB-MS) data. Crassostreaxanthin A 3-acetate and crassostreaxanthin B 3-acetate were first isolated and completely characterized by spectroscopic data. Furthermore, possible metabolic pathways of fucoxanthin in clams were proposed.

Structure of minor carotenoids from the crown-of-thorns starfish, Acanthaster planci.

Four new carotenoids, named 4-ketodeepoxyneoxanthin (1), 4-keto-4'-hydroxydiatoxanthin (2), 3'-epigobiusxanthin (3), and 7,8-dihydrodiadinoxanthin (4), were isolated from the crown-of-thorns starfish, Acanthaster planci. Their structures were determined on the basis of chemical and spectroscopic data.

New C37 skeletal carotenoid from the clam, Paphia amabillis.

Carotenoids in the muscle of Paphia amabillis (Veneridae) were investigated. Amarouciaxanthin 3-ester (1a) was found to be a major carotenoid along with amarouciaxanthin A (1b), fucoxanthinol 3-ester (2), peridininol 3'-ester (3), and a new C(37) skeletal carotenoid, named hydratopyrrhoxanthinol 3'-ester. This structure was determined to be 3'-acyloxy-3,5,6-trihydroxy-7',8'-didehydro-5,6-dihydro-12',13',20'-trinor-beta,beta-caroten-19,11-olide (4) by UV-vis, NMR, and FAB-MS spectral data. The absolute configuration of 4 was postulated to be (3S,5R,6R,3'R) on the bases of CD and ROESY data. The fatty acids esterified with hydratopyrrhoxanthinol were assigned as C22:6, C20:1, C20:4, C20:5, C18:0, C18:1, C17:0, C16:0, C16:1, and C14:0 on the basis of FAB-MS data.

Carotenoids in a Corynebacterineae, Gordonia terrae AIST-1: carotenoid glucosyl mycoloyl esters.

We isolated a strain of Corynebacterineae from surface seawater from the Inland Sea of Japan. This strain, AIST-1, was determined to be a strain of Gordonia terrae based on its 16S rRNA gene sequence. The colony was red-colored, and the pigments were identified to be carotenoid derivatives. The structures of two major carotenoids were (2'S)-deoxymyxol 1'-glucoside, a dihydroxyl derivative of gamma-carotene with 12 conjugated double bonds, and (2'S)-4-ketodeoxymyxol 1'-glucoside. Their glucosyl acyl esters and mycoloyl esters were also identified. While these carotenoid moieties have been found in only a few other bacteria, the carotenoid mycoloyl esters are novel carotenoid derivatives. The type strain of G. terrae NBRC 10016T also contained the same carotenoids, but the composition of the two carotenoid glucosides was low and the total carotenoid content was less than one tenth of that of strain AIST-1.

Pittosporumxanthins, cycloaddition products of carotenoids with alpha-tocopherol from seeds of Pittosporum tobira.

A series of carotenoid-alpha-tocopherol cycloaddition products, named pittosporumxanthins B1 ( 3), B2 ( 4), C1 ( 5), C2 ( 6), A3 ( 7), and A4 ( 8), were isolated from the seeds of Pittosporum tobira. The structures were determined to be cycloaddition products of 9' Z-antheraxanthin at the 11' and 12' positions with alpha-tocopherol ( 3 and 4), 9' Z-neoaxanthin with alpha-tocopherol ( 5 and 6), and 9 Z-violaxanthin with alpha-tocopherol ( 7 and 8) on the basis of a detailed analyses of MS and NMR spectroscopic data. The configurations of the carotenoid end groups in the pittosporumxanthins were determined by a modified Mosher's method. Compounds 3, 5, and 7 were assigned (11' R,12' S) and 4, 6, and 8 (11' S,12' R) absolute configurations using CD measurements.

Carotenoids and their fatty acid esters of spiny lobster Panulirus japonicus.

Carotenoids and their fatty acid esters in the carapace of the spiny lobster Panulirus japonicus were investigated. Fatty acid esters of astaxanthin, adonixanthin, and pectenolone were characterized by (1)H-NMR and FAB-MS. The acylated position of adonixanthin and pectenolone monoesters was determined to be a hydroxy group at C-3' by (1)H-NMR. The fatty acids esterified with these carotenoids were identified as C22:6, C20:4, C20:5, C18:0, C18:1, C17:0, C16:0, C16:1, C14:0, and C12:0 from FAB-MS spectral data. Furthermore, 2,3-didehydrocanthaxanthin (4) was first identified as a natural product.

Carotenoids with a 5,6-dihydro-5,6-dihydroxy-beta-end group, from yellow sweet potato "Benimasari", Ipomoea batatas Lam.

A series of carotenoids with a 5,6-dihydro-5,6-dihydroxy-beta-end group, named ipomoeaxanthins A (1), B (2), C1 (3) and C2 (4) were isolated from the flesh of yellow sweet potato "Benimasari", Ipomoea batatas Lam. Their structures were determined to be (5R,6S,3'R)-5,6-dihydro-beta,beta-carotene-5,6,3'-triol (1), (5R,6S,5'R,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-5,6,5'6'-tetrol (2), (5R,6S,5'R,8'R)-5',8'-epoxy-5,6,5',8'-tetrahydro-beta,beta-carotene-5,6-diol (3), and (5R,6S,5'R,8'S)-5',8'-epoxy-5,6,5',8'-tetrahydro-beta,beta-carotene-5,6-diol (4) by UV-Vis, NMR, MS and CD data.

Characterization of fucoxanthin and fucoxanthinol esters in the Chinese surf clam, Mactra chinensis.

Fucoxanthin and fucoxanthinol fatty acid esters in the clam, Mactra chinensis, were characterized on the basis of 1H NMR and FAB-MS spectra. 1H NMR revealed that the hydroxy group at C-3 in fucoxanthin and fucoxanthinol was acylated. 3'-O-Acylated compounds such as fucoxanthinol 3'-ester or fucoxanthinol 3,3'-diester were not found in the clam. The fatty acids esterified with fucoxanthin and fucoxanthinol were identified as C24:6, C22:5, C22:6, C20:5, C20:0, C20:1, C18:0, C18:1, C16:0, C16:1, and C14:0 by FAB-MS data.

Major carotenoid isolated from Paracoccus schoinia NBRC 100637T is adonixanthin diglucoside.

The structure of a novel major carotenoid glycoside (nearly 80% of total carotenoids) from a newly isolated bacterium, Paracoccus schoinia NBRC 100637T, was determined to be adonixanthin diglucoside using spectral data. By contrast, carotenoid diglycosides are rare and are usually minor carotenoids in nature. The minor carotenoids in this bacterium included astaxanthin diglucoside, zeaxanthin diglucoside, canthaxanthin, echinenone, zeaxanthin, beta-cryptoxanthin, and beta-carotene.

2,3'-Dihydroxycanthaxanthin, a new carotenoid with a 2-hydroxy-4-oxo-beta-end group from the hermit crab, Paralithodes brevipes.

A new carotenoid with a 2-hydroxy-4-oxo-beta-end group was isolated from the hermit crab, Paralithodes brevipes, as a minor component. Its structure was determined to be 2,3'-dihydroxy-beta,beta-carotene-4,4'-dione (1) by spectral data and the compound was named 2,3'-dihydroxycanthaxanthin. Chiral resolution of 1 by HPLC using a chiral column provided two stereoisomers, 1a and 1b. The 3'R and 3'S chirality were determined for 1a and 1b, respectively, by CD spectra.

5-Hydroxy-seco-carotenoids from Pittosporum tobira.

Three 5-hydroxy-seco-carotenoids were isolated from seeds of Pittosporum tobira. These structures were determined to be (3S,3'S,5'?)-3,3'-di(tetradecanoyloxy)-5'-hydroxy-5,6,5',6'-diseco-beta,beta-carotene-5,6,6'-trione (1), (3S,5?,3'S,5'R,6'S,9'Z)-3-tetradecanoyloxy-5',6'-epoxy-5,3'-dihydroxy-5',6'-dihydro-5,6-seco-beta,beta-caroten-6-one (2), and (3S,5?,3'S,5'R,6'R)-3-tetradecanoyloxy-5,3',5'-trihydroxy-6',7'-didehydro-5',6'-dihydro-5,6-seco-beta,beta-caroten-6-one (3) based on analysis of UV-vis, IR, FAB MS, and NMR spectroscopic data.

Carotenoids in three species of Corbicula Clams, Corbicula japonica, Corbicula sandai, and Corbicula sp. (Chinese Freshwater Corbicula Clam).

Carotenoids were investigated in three species of corbicula clams, Corbicula japonica, Corbicula sandai, and Corbicula sp. (Chinese freshwater corbicula clam). Forty-three carotenoids were isolated. Among them, 7,8-didehydro-beta-cryptoxanthin (12), peridininol 5,8-furanoxide (38), pyrrhoxanthin 5,8-furanoxide (40), and pyrrhoxanthinol 5,8-furanoxide (43) are newly reported as naturally occurring carotenoids. Their structures were characterized on the basis of UV-vis, FAB-MS including MS/MS experiments, and 1H NMR spectroscopic data. The total carotenoid contents in C. japonica, C. sandai, and Chinese freshwater corbicula clam were found to be 5.3, 2.6, and 0.3 mg/100 g in the edible part (wet weight), respectively. Peridinin (34) and its derivatives were found to be major carotenoids in C. japonica, which inhabits brackish water. On the other hand, lutein (13) was found to be the major carotenoid in C. sandai and Chinese corbicula clams, which inhabit freshwater. These patterns well reflected the carotenoids in their dietary algae. 7',8'-Didehydrodeepoxyneoxanthin (19), corbiculaxanthin (21), corbiculaxanthin 3'-acetate (22), and 6-epiheteroxanthin (24) were found in all three species of corbicula clams and have not previously been found in other shellfishes. They were assumed to be peculiar carotenoids in corbicula clams.

Structure of new carotenoids from corbicula clam Corbicula japonica.

Six new carotenoids, named corbiculaxanthin (1), corbiculaxanthin 3'-acetate (2), 6-epiheteroxanthin (3), 7',8'-didehydrodeepoxyneoxanthin (4), cyclopyrrhoxanthin (5), and hydratoperidinin (6), were isolated from the corbicula clam (Shijimi in Japanese), Corbicula japonica. Their structures were determined by chemical and spectral data.

Structure of new carotenoids with a 3,4-dihydroxy-beta-end group from the oyster Crassostrea gigas.

Three new carotenoids with a 3,4-dihydroxy-beta-end group were isolated from the oyster Crassostrea gigas. These structures were determined to be 3,4,3',8'-tetrahydroxy-beta,kappa-caroten-6'-one (1), 3,4-dihydroxy-3',6'-epoxy-1',2',5',6'7',8'-hexahydro-6'-methyl-16'-nor-beta,-carotene-1',8'-dione (2), and 3,6-epoxy-5,3',4'-trihydroxy-12',13',20'-trinor-beta,beta-caroten-19,11-olide (3) based on chemical and spectral data.

Characterization of epoxy carotenoids by fast atom bombardment collision-induced dissociation MS/MS.

The characterization and structure of epoxy carotenoids possessing 5,6-epoxy, 5,8-epoxy and 3,6-epoxy end groups conjugated to the polyene chain were investigated using high-energy fast atom bombardment collision-induced dissociation MS/MS methods. In addition to [M - 80](+*), a characteristic fragment ion of an epoxy carotenoid, product ions resulting from the cleavage of C-C bonds in the polyene chain from the epoxy end group, such as m/z 181 (b ion) and 121 (c ion), were detected. On the other hand, diagnostic ions of m/z 286 (e-H ion) and 312 (f-H ion) were observed, not in the 5,6-epoxy or 5,8-epoxy carotenoid but in the 3,6-epoxy carotenoid. These fragmentation patterns can be used to distinguish 3,6-epoxy carotenoids from 5,6-epoxy or 5,8-epoxy carotenoids. The structure of an epoxy carotenoid, 3,6-epoxy-5,6-dihydro-7',8'-didehydro-beta,beta-carotene-5,3'-diol (8), isolated from oyster, was characterized using FAB CID-MS/MS by comparing fragmentation patterns with those of related known compounds.

Structure of new carotenoids with the 6-oxo-kappa end group from the fruits of paprika, Capsicum annuum.

New carotenoids 1 and 2 were isolated as minor components from the ripe fruits of paprika (Capsicum annuum). The structures of 1 and 2 were determined to be (3R,5'R)-3-hydroxy-beta,kappa-caroten-6'-one and (5'R)-3,4-didehydro-beta,kappa-caroten-6'-one, respectively, from UV-vis, NMR, CD, HRFABMS, and FABMS/MS spectra.