Constituents of holothuroidea, 14. Isolation and structure of new glucocerebroside molecular species from the sea cucumber Stichopus japonicus

Five glucocerebroside molecular species, SJC-1-SJC-5, have been isolated from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Stichopus japonicus. The structures of these glucocerebroside molecular species were determined on the basis of chemical and spectroscopic evidence. SJC-1, SJC-2, and SJC-3 are typical sphingosine- and phytosphingosine-type glucocerebroside molecular species with nonhydroxylated and hydroxylated fatty acyl moieties. SJC-4 and SJC-5 are also sphingosine-type glucocerebroside molecular species with hydroxylated fatty acyl moieties, although they are new glucocerebroside molecular species with unique sphingosine bases.     

Constituents of holothuroidea, 12. Isolation and structure of glucocerebrosides from the sea cucumber Holothuria pervicax

Ten glucocerebrosides, HPC-3-A-HPC-3-J, have been isolated from their obtained parent glucocerebroside molecular species HPC-3, together with other glucocerebroside molecular species HPC-1 and HPC-2, from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Holothuria pervicax. The structures of these glucocerebrosides have been determined on the basis of chemical and spectroscopic evidence. Reversed-phase HPLC, including a recycling system, was effective in isolating these glucocerebrosides, revealing a very close resemblance in structure, though the problem due to regio-isomers remains.     

Constituents of Holothuroidea, 15. Isolation of ante-iso type regio-isomer on long chain base moiety of glucocerebroside from the sea cucumber Holothuria leucospilota

An ante-iso type regio-isomer on the long chain base moiety of a glucocerebroside, HLC-2-A, has been isolated from its parent glucocerebroside molecular species HLC-2 composed of iso and ante-iso isomers, from the less polar lipid fraction of a chloroform/methanol extract of the sea cucumber Holothuria leucospilota. Reverse-phase HPLC that included a recycling system was effective in separating the regio-isomer from its counterpart, revealing a very close resemblance in structure. Other typical glucocerebroside molecular species HLC-1 and HLC-3 were obtained together with HLC-2. The structures of these glucocerebrosides were determined on the basis of chemical and spectroscopic evidence.     

Constituents of holothuroidea, 16. Determination of Absolute configuration of the branched methyl group in ante-iso type side chain moiety on long chain base of glucocerebroside from the sea cucumber Holothuria leucospilota

The absolute configuration of the branched methyl group in ante-iso type side chain moiety on the long chain base of glucocerebroside, HLC-2-A, which was isolated from the sea cucumber Holothuria leucospilota was determined. Oxidation of the glucocerebroside with ozone afforded C13-fragment including the ante-iso moiety. The optically active C13-fragment was synthesized asymmetrically by using the Wittig reaction from chiral synton for comparison with the natural fragment.     

Constituents of Crinoidea, 4. Isolation and structure of ceramides and glucocerebrosides from the feather star Comanthus japonica

Five ceramides, JC-1-JC-5, and four glucocerebrosides, JCer-1-JCer-4, have been isolated from their parent ceramide and glucocerebroside molecular species JC and JCer obtained from the less polar lipid fraction of the chloroform/methanol extract of the feather star Comanthus japonica. The structures of these sphingolipids have been determined on the basis of chemical and spectroscopic evidence. Reversed-phase HPLC was effective at isolating these sphingolipids, revealing very close resemblance in their structures. JC-1, JC-3, JC-4, JC-5 and JCer-2, JCer-4 are newly found ceramides and glucocerebrosides, respectively.     

Efficient stereocontrolled synthesis of sphingadienine derivatives

Sphinga-4,8-dienines, principal long-chain bases of glycolipids in plants and fungi, were efficiently synthesized from l-serine. Hydrozirconation of pentadec-5-en-1-ynes followed by ZnBr₂-catalyzed addition to Garner's aldehyde afforded protected sphinga-4,8-dienines stereoselectively. The (2S,3R,4E,8E)-9-methyl-sphingadienine derivative was then coupled with 2(R)-acetoxypalmitic acid derivative prepared via asymmetric dihydroxylation to give a protected ceramide, which was converted into the corresponding glucocerebroside in two steps.     

Comparative analysis of ceramide structural modification found in fungal cerebrosides by electrospray tandem mass spectrometry with low energy collision-induced dissociation of Li+ adduct ions

Fungal cerebrosides (monohexosylceramides, or CMHs) exhibit a number of ceramide structural modifications not found in mammalian glycosphingolipids, which present additional challenges for their complete characterization. The use of Li+ cationization, in conjunction with electrospray ionization mass spectrometry and low energy collision-induced dissociation tandem mass spectrometry (ESI-MS/CID-MS), was found to be particularly effective for detailed structural analysis of complex fungal CMHs, especially minor components present in mixtures at extremely low abundance. A substantial increase in both sensitivity and fragmentation was observed on collision-induced dissociation of [M + Li]+ versus [M + Na]+ of the same CMH components analyzed under similar conditions. The effects of particular modifications on fragmentation were first systematically evaluated by analysis of a wide variety of standard CMHs expressing progressively more functionalized ceramides. These included bovine brain galactocerebrosides with non-hydroxy and 2-hydroxy fatty N-acylation; a plant glucocerebroside having (E/Z)-delta8 in addition to (E)-delta4 unsaturation of the sphingoid base; and a pair of fungal cerebrosides known to be further modified by a branching 9-methyl group on the sphingoid moiety, and to have a 2-hydroxy fatty N-acyl moiety either fully saturated or (E)-delta3 unsaturated. The method was then applied to characterization of both major and minor components in CMH fractions from a non-pathogenic mycelial fungus, Aspergillus niger; and from pathogenic strains of Candida albicans (yeast form); three Cryptococcus spp. (all yeast forms); and Paracoccidioides brasiliensis (both yeast and mycelium forms). The major components of all species examined differed primarily (and widely) in the level of 2-hydroxy fatty N-acyl delta3 unsaturation, but among the minor components a significant degree of additional structural diversity was observed, based on differences in sphingoid or N-acyl chain length, as well as on the presence or absence of the sphingoid delta8 unsaturation or 9-methyl group. Some variants were isobaric, and were not uniformly present in all species, affirming the need for MS/CID-MS analysis for full characterization of all components in a fungal CMH fraction. The diversity in ceramide distribution observed may reflect significant species-specific differences among fungi with respect to cerebroside biosynthesis and function.     

Triterpenoid saponins from Lysimachia davurica

Three new saponins were isolated from the whole plants of Lysimachia davurica. On the basis of 1D and 2D NMR ((1)H-(1)HCOSY, HMBC, HMQC, and TOCSY) techniques, MS, and hydrolysis, their structures were found to be 3-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl-13,28-epoxy-3beta-hydroxy-16-oleanaone (1), 3-O-beta-D-glucopyranosyloxyuronic acid-(1-->2)-beta-D-xylopyranosyl-cyclamiretin A (2), and 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-cyclamiretin A (3), respectively. Compounds 2 and 3 showed significant cytotoxicities against human A-2780 cells.     

Cytotoxic hydroxyanthracenones from fruits of Karwinskia parvifolia

Peroxisomicines A1 (1) and A2 (2) are cytotoxic hydroxyanthracenones isolated from the fruits of Karwinskia parvifolia. Peroxisomicine A1 exhibits selective cytotoxicity against several tumor cell lines. In the present investigation three minor constituents were obtained from the same fruit extracts: peroxisomicine A3 (3) and isoperoxisomicines A1 (4) and A2 (5). Compounds 3 and 5 are novel and their structures were determined by spectroscopic methods and molecular modeling. Compounds 1-5 were significantly cytotoxic against hepatoma cell lines.     

Isoflavones from Ficus nymphaefolia

A new isoflavone, 5,7-dihydroxy-4'-methoxy-3'-(2,3-dihydroxy-3-methylbutyl)isoflavone (1) was isolated from the stem bark of Ficus nymphaefolia Mill. (Moraceae) together with eight known isoflavones: genistein, erycibenin A, cajanin, 5,7,2'-trihydroxy-4'-methoxyisoflavone, erythrinin C, alpinumisoflavone, derrone and 3'-(3-methylbut-2-enyl)biochanin A. Their structures were established by spectral analysis including 1D and 2D NMR experiments.     

Abietane lactones and iridoids from Goldfussia yunnanensis

Two new abietane diterpene lactones (1--2), three new abietane diterpene lactone glycosides (3--5) and a new iridoid glycoside (6), together with five known compounds, were isolated from the aerial parts of Goldfussia yunnanensis. The new compounds were determined to be 18-hydroxyhelioscopinolide A (1), 18-oxohelioscopinolide A (2), 18-hydroxy-3-O-beta-D-glucopyranosylhelioscopinolide A (3), 3-O-beta-D-glucopyranosylhelioscopinolide A (4), 3-O-beta-D-galactopyranosylhelioscopinolide A (5), and 6-O-trans-cinnamoyl E-harpagoside (6) on the basis of spectral data and chemical evidence.     

New triterpenoids from Corchorus trilocularis

Two new tetracyclic triterpenoid trilocularol A and trilocularol A 3-glucoside and one pentacyclic triterpenoid tirlocularoside A were isolated from Corchorus trilocularis L., their structure were elucidated as 3beta,6alpha,16alpha,20(S),27-pentahydroxydammar-24(Z)-ene (1), 3beta-D-glucopyranosyloxy-6alpha,16alpha,20(S),27-tetrahydroxydammar-24(Z)-ene (2) and 2alpha,3beta,19alpha,30-tetrahydroxyurs-12-en-24,28-dioic acid 28-O-beta-D-glucopyranosyl ester (3). respectively, on the basis of detailed spectroscopic studies.     

New triterpenoid saponins from Maesa tenera.

Two new triterpenoid saponins, maetenosides A and B were isolated from the aerial parts of Maesa tenera and were respectively defined as 3-O-[beta-D-glucopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)][beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl camelliagenin A 22-O-angelate (1) and 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)][beta-o-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl camelliagenin A 22-O-angelate (2). Their structures were established on the basis of chemical and spectroscopic methods.     

A new naphthopyrone from the root of Pleuropterus ciliinervis

A new naphthopyrone, pleuropyrone A (1), together with (-)-lyoniresinol 3a-O-beta-D-glucopyranoside (2) and (+)-lyoniresinol 3a-O-beta-D-glucopyranoside (3) was isolated from the roots of Pleuropterus ciliinervis. The structure of pleuropyrone A (1) was determined to be 2,5-dimethyl-8-hydroxynaphthopyrone 10-O-beta-D-glucopyranoside by spectroscopic methods including 2D-NMR. Compounds 2 and 3 showed moderate antioxidant activity.     

Lucidin type anthraquinone glycosides from Putoria calabrica

Two new lucidin type anthraquinone glycosides, putorinoside A (1) and putorinoside B (2) were isolated from Putoria calabrica, in addition to two known anthraquinone glycosides, lucidin 3-O-beta-glucopyranoside (3) and lucidin 3-O-primeveroside (4). Based on spectroscopic data, putorinosides A and B were identified as 2-hydroxymethyl-1-methoxy-3,5,6-trihydroxyanthraquinone 3-O-beta-glucopyranoside and 2-hydroxymethyl-1-methoxy-3,6-dihydroxyanthraquinone 3-O-beta-glucopyranoside, respectively.     

Two new compounds from Coriaria nepalensis

Two new compounds,corialins A(1) and B(2) were isolated from Coriaria nepalensis Wall.These new compounds were established as 7-hydroxy-3-[2,3-acetonide-(3-methylbutane)]coumarin(1) and 3-O-β-D-glucopyranosyl-3,4,5-trihydroxy-1-(3- methyl-2-butenyl)-benzene(2),on the basis of 1D and 2D NMR techniques.     

Sulfur-containing compounds from Clinacanthus siamensis

Two new sulfur-containing compounds, trans-3-methylsulfonyl-2-propenol (1) and trans-3-methylsulfinyl-2-propenol (2) were isolated together with trans-3-methylthioacrylamide (3), entadamide A (4) and entadamide C (5) from the leaves of Clinacanthus siamensis. The structures were established on the basis of the spectroscopic data. The compounds were tested for antimalarial and antimycobacterial activity.     

Antioxidant xanthones from Cratoxylum cochinchinense

A new xanthone named cratoxylumxanthone A (1), together with five known compounds: dulcisxanthone B (2), alpha-mangostin (3), beta-mangostin (4), 2-geranyl-1,3,7-trihydroxy-4-(3-methylbut-2-enyl)xanthone (5) and tectochrystin (6), was isolated from Cratoxylum cochinchinense stems. The structure of new compound was characterized by 1D and 2D NMR techniques. The isolated compounds showed free radical scavenging against DPPH and lipid peroxidation inhibition.     

B-norsteroids from Hymenoscyphus pseudoalbidus

Two viridin-related B-norsteroids, B-norviridiol lactone (1) and B-norviridin enol (2), both possessing distinct unprecedented carbon skeletons, were isolated from a liquid culture of the ash dieback-causing fungus Hymenoscyphus pseudoalbidus. Compound 2 was found to degrade to a third B-norsteroidal compound, 1β-hydroxy-2α-hydro-asterogynin A (3), which was later detected in the original culture. The proposed structure of 1 is, regarding connectivity, identical to the original erroneous structure for TAEMC161, which was later reassigned as viridiol. Compound 2 showed an unprecedented 1H-13C HMBC correlation through an intramolecular hydrogen bond. The five-membered B-ring of compounds 1-3 was proposed to be formed by a benzilic acid rearrangement. The known compound asterogynin A was found to be formed from 3 by a β-elimination of water. All compounds were characterized by NMR spectroscopy, LC-HRMS and polarimetry.     

A new eudesmane sesquiterpene from Pluchea arguta

A new eudesmane sesquiterpene, pluchargen A (3-beta-[3'-chloro-2'-hydroxy-2'-methyl butyroyl]-cuauhtemone), was isolated from the whole plant of Pluchea arguta, and the structure was elucidated on the basis of 1- and 2-D NMR spectroscopic studies.