Identification de stérols à chaînes latérales courtes dans l′éponge Damiriana hawaiiana

Identification of short side chain sterols in the sponge Damiriana hawaiiana The steroidal composition of the sponge Damiriana hawaiiana is examined. Twenty-seven components are identified. In addition to the C₂₆-C₂₉, Δ⁵-mono and diunsaturated sterols, the sponge contains sterols without side-chain: androsta-5, 16-dien-3β-ol( 1 ), androst-5-en-3β-ol( 2 ); sterols with a non-functionalized side-chain consisting of two, three, four, five and six carbon atoms: pregna-5, 20-dien-3β-ol( 5 ), pregn-5-en-3β-ol( 6 ), 23, 24-bisnor-chola-5, 20-dien-3β-ol( 7 ), 23, 24-bisnor-chol-5-en-3β-ol( 8 ), 24-nor-chol-5-en-3β-ol( 10 ), chol-5-en-3β-ol( 11 ), 26, 27-bisnor-cholest-5-en-3β-ol( 12 ), and sterols possessing a short oxygenated side-chain such as 3β-hydroxy-androst-5-en-17-one( 3 ), androst-5-en-3β, 17β-diol( 4 ) and 3β-hydroxy-26, 27-bisnor-22-trans-cholesta-5, 22-dien-24-one( 14 ). The probable biological or dietary origin rather than artifact production of these hitherto undescribed components from marine sources is supported by their relatively high concentration and their relative proportions, both very different from those expected for autoxidation.     

Carbon-13 NMR spectra of some tetra- and pentacyclic triterpenoids

The carbon-13 NMR spectra of lanosta-8-en-3β-ol, lanosta-8, 24-dien-3β-ol, lanosta-7,9(11)-dien-3β-ol, lanostan-3β-ol, eupha-8-en-3β-ol, eupha-8,24-dien-3β-ol, ursa-12-en-3β-ol (α-amyrin) and oleana-12-en-3β-ol (β-amyrin) have been obtained and completely assigned. The results of this study provide chemical shift data for methyl, methylene, methine and quaternary carbon atoms in tetra- and pentacyclic triterpenoid spectra. The carbon-13 NMR spectrum of a triterpenoid provides a unique fingerprint for the molecule.     

Specific oxidation of C-14 oxygenated 4(20),11-taxadienes by microbial transformation

Three C-14 oxygenated taxanes, 2α,5α,10β,14β-tetraacetoxytaxa-4(20),11-diene (1), 2α,5α,10β-triacetoxy-14β-(2-methylbutyryloxy)taxa-4(20),11-diene (2), and yunanaxane (3), major products of callus cultures of Taxus spp., were regio- and stereoselectively hydroxylated at the 7β position by a fungus, Absidia coerulea IFO 4011. Intriguingly, when 1 was co-administered with β-cyclodextrin and incubated with the fungus cell cultures, three other compounds 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-14β-ol (7), 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-1β-ol (8) and 5α,9α,10β,13α-tetraacetoxy-11(15→1) abeotaxa-4(20),11-dien-15-ol (9) were obtained.     

Steroids and an oxylipin from an algicolous isolate of Aspergillus flavus

A new oxylipin, (8E,12Z)-10,11-dihydroxyoctadeca-8,12-dienoic acid (1), a new steroid, 3β,4α-dihydroxy-26-methoxyergosta-7,24(28)-dien-6-one (2), and four known steroids, episterol (3), (22E,24R)-ergosta-7,22-dien-3β,5α,6α-triol (4), (22E,24R)-ergosta-5,22-dien-3β-ol (5), and (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (6), were isolated from the cultures of Aspergillus flavus, an endophytic fungus isolated from the marine red alga Corallina officinalis. Their structures and relative stereochemistry were elucidated by 1D, 2D NMR and mass spectroscopic techniques. 1 and 2 exhibited low activity to inhibit acetylcholinesterase and no activity against plant pathogenic fungi Colletotrichum lagenarium and Fusarium oxysporum.     

Autoxidation of isotachysterol

Isotachysterol, the acid-catalyzed isomerization product of vitamin D₃, produces seven previously unknown oxygenation products in a self-initiated autoxidation reaction under atmospheric oxygen in the dark at ambient temperature. They are (5R)-5,10-epoxy-9,10-secocholesta-6,8(14)-dien-3β-ol (6a), (5S)-5,10-epoxy-9,10-secocholesta-6,8(14)-dien-3β-ol (6b), (10R)-9,10-secocholesta-5,7,14-trien-3β,10-diol (7a), (10S)-9,10-secocholesta-5,7,14-trien-3β,10-diol (7b), (7R,10R)-7,10-epoxy-9,10-secocholesta-5,8(14)-dien-3β-ol (8), 5,10-epidioxyisotachysterol (9) and 3,10-epoxy-5-oxo-5,10-seco-9,10-secocholesta-6,8(14)-dien-10-ol (10). The formation of these products is explained in terms of free radical peroxidation chemistry.     

Sterol sulfates from the Far Eastern holothurianCucumaria japonica

A chloroform-methanol extract of the musculocutaneous sac of the Far-Eastern holothurianC. japonica has yielded a fraction of sterol sulfates (13% of the weight of the extract, 0.8% of the weight of the dry biomass), the main components of which were derivatives of cholest-5-en-3β-ol, 24-methylene-, 24-ethyl-, and 24-ethylidenecholest-5-en-3β-ols, 5α-cholestan-3β-ol, and 24-methyl- and 24-methylene-5α-cholesten-3β-ol; among the minor components were found the sulfates of 24-ethyl-5α-cholestan-3β-ol of cholesta-5,22-dien-3β-ol, of a Δ⁵-C₃₀ sterol, and also of dienic and trienic C₂₆ sterols.     

Steroid alcohols from the ascidianHalocynthia aurantium

The total sterols have been isolated fromHalocynthia aurantium by column chromatography on silica gel. The following steroid alcohols have been identified in it with the aid of GLC, GLC-MS, and¹H NMR: 5α-cholestan-3β-ol, 24ξ-methylcholestan-3β-ol, 24ξ-ethylcholestan-3β-ol, 4ξ-methyl-24ξ-ethyl-5α-cholestan-3β-ol, cholest-5-en-3β-ol, 24ξ-methylcholest-5-en-3β-ol, 24ξ-ethylcholes-5-en-3β-ol, 5α-cholest-22-en-3β-ol, 24-nor-5α-cholest-22-en-3β-ol, cholesta-5,22-dien-3β-ol, 24ξ-methylcholesta-5,22-dien-3β-ol, 24-norcholesta-5,22-dien-3β-ol, 24-ethylcholesta-5,24(28)-dien-3β-ol, and 24-methylcholesta-5,24(28)-dien-3β-ol.     

Sesquiterpenoids and norsesquiterpenoids from three liverworts

Six new sesquiterpenoids and two new norsesquiterpenoids were isolated from the essential oils of three liverworts. The isolated compounds include (+)-eudesma-4,11-dien-8α-ol from the liverwort Diplophyllum albicans, (−)-4β,5β-diacetoxygymnomitr-3(15)-ene, (+)-5β-acetoxygymnomitr-3(15)-ene, (−)-15-acetoxygymnomitr-3-ene, (−)-3β,15β-epoxy-4β-acetoxygymnomitrane, and (−)-3α,15α-epoxy-4β-acetoxygymnomitrane from Marsupella emarginata, and (+)-1,2,3,6-tetrahydro-1,4-dimethylazulene and (−)-2,3,3a,4,5,6-hexahydro-1,4-dimethylazulen-4-ol from Barbilophozia floerkei. These compounds were isolated by a combination of different chromatographic techniques, and their structures were determined by extensive spectroscopic studies (MS, ¹H, ¹³C, and 2D NMR) and chemical transformations using enantioselective GC.     

Tomatoside a from the seeds ofLycopersicum esculentum

Results are given which confirm the structure of the furostanol glycoside from tomato seeds forming wastes of the preserving industry. From a butanolic extract of the seeds ofLycopersicum esculentum Mill. we have isolated the furostanol glycoside tomatoside A (I) the structure of which has been established as 25(S)-5α-furostan-3β,22α,26-triol 26-O-β-D-glucopyranoside 3-O-[O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside]. At the same time, by enzymatic and chemical transformations three new spirostanol glycosides of neotigogenin have been obtained: tomatoside B (III), which is 25(S)-5α-spirostan-3β-ol 3-O-[O-β-D-glucopyranosyl-(1→2)-β-D-galactopyranoside], 25(S)-5α-spirostan-3β-ol 3-O-[O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside] (V), and 25(S)-5α-spirostan-3β-ol 3-O-β-D-galactopyranoside (IV).     

Sesquiterpenoids from Costus Root Oil (Saussurea lappa CLARKE)

Apart from the well-known constituents (+)-β-selinene ( 2 ), (?)-β-elemene ( 4 ), (+)-β-costol ( 7 ), (?)-caryophyllene ( 17 ), and (?)-elemol ( 19 ) the following sesquiterpenoids have been isolated for the first time from costus root oil (Saussurea lappa CLARKE ): (?)-α-selinene ( 1 ), (+)-selina-4, 11-diene ( 3 ), (?)-α-trans-bergamotene ( 5 ), (?)-α-costol ( 6 ), (+)-γ-costol ( 8 ), (?)-elema-1,3,11 (13)-trien-12-ol ( 9 ), (?)-α-costal ( 11 ), (+)-γ-costal ( 12 ), (+)-γ-costal ( 13 ), (?)-elema-1,3,11 (13)-trien-12-al (elemenal, 14 ), (?)-(E)-trans-bergamota-2, 12-dien-14-al ( 15 ), (?)-ar-curcumene ( 16 ), and (?)-caryophyllene oxide ( 18 ). Compounds 6 , 8 , 9 , and 13 are new sesquiterpenoids. IR. and NMR. spectra of 12 sesquiterpenoids are reproduced.     

Two new epoxysteroids from Helianthus tuberosus

Two new epoxy steroids, 5α,8α-epidioxy-22β,23β-epoxyergosta-6-en-3β-ol (1) and 5α,8α-epidioxy-22α,23α-epoxyergosta-6-en-3β-ol (2), and ten known steroids including (24R)-5α,8α-epidioxyergosta-6-en-3β-ol (3), (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (4), (22E,24R)-5α,8α-epidioxyergosta-6,9(11),22-trien-3β-ol (5), β-sitosterol (6), sitost-5-en-3β-ol acetate (7), 7α-hydroxysitosterol (8), schleicheol 2 (9), (24R)-24-ethyl-5α-cholestane-3β,5α,6β-triol (10), 7α-hydroxystigmasterol (11), and stigmasterol (12) were isolated from Helianthus tuberosus grown in Laizhou salinized land of coastal zone of Bohai Sea, China. The structures of these compounds were unambiguously established by 1D, 2D NMR and mass spectroscopic techniques. The new compounds 1 and 2 exhibited weak antibacterial activity and no antifungal activity.     

Marine sterols—II : Asterosterol,a new C26 sterol from Asterias amurensis lütken

Asterosterol, a new marine C₂₆ sterol, was isolated from the asteroid, A. amurensis, and its structure was characterized as 22-trans-24-nor-5α-cholesta-7,22-dien-3β-ol (1). Episterol (9), 22-trans-(24R)-24-methylcholesta-7,22-dien-3β-ol (stellasterol, 3) and 22-trans-cholesta-7,22-dien-3β-ol (7) were also isolated and their structures were confirmed.     

Triterpene saponins with XOD inhibitory activity from the roots of Ilex pubescens

A new triterpene saponin with 28-nor-urs-12(13),18(17)-dien-3β-ol as aglycone,named ilexsaponin C(1) was isolated from the roots of Ilex pubescens,together with three known saponins 2,3 and 4.The structure of 1 was elucidated on the basis of spectral analysis including 1D and 2D NMR and HR-ESI-MS.Saponins 1 and 4 exhibited significant XOD inhibitory activity in the test.     

Studies on the Constituents of Ganoderma Lucidum

The methanolic extract of fruit bodies of cultivated Ganoderma lucidum was separated by silica gel column chromatography and preparative thin-layer chromatography to give ten compounds. On the basis of spectral analysis, chemical procedures and gas chromatography, d-mannitol (1), ergosta-7, 22-dien-3β-yl palmitate (2), ergosterol (3), ergosta-7, 22-dien-3β-ol (4), 5α-lanosta-7,9(11),24-trien-3β,26-diol (5), ergosterol peroxide (6), 24,25,26-trihydroxy-5α-lanosta-7,9(11)-dien-3-one (7), 5α-lanosta-7,9(11)-dien-3β,24,25,26-tetraol (8) and 8,9-epoxyergosta-5,22-dien-3β,15-diol (9) were identified. Among these compounds, 8,9-epoxyergosta-5,22-dien-3β,15-diol was first separated from Ganoderma lucidum.     

Chemical constituents from the roots of Xanthium sibiricum

Xanthium sibiricum patrin ex Widder (Compositae) is an annual herb which grows all around China. Chemical investigations of its roots resulted in the identification of 15 compounds: stigmast-4-en-6β-ol-3-one (1), β-sitostenone (2), β-sitosterol (3), nonadecanoic acid (4), 5α,8α-epidioxy-22E-ergosta-6,22-dien-3β-ol (5), scopoletin (6), Jatrocin B (7), (±)syringaresinol (8), 9,9'-O-di-(E)-feruloyl-(-)-secoisolariciresinol (9), cleomiscosin A (10), cleomiscosin C (11), N-trans-feruloyl tyramine (12), daucosterol (13), 5-methyluracil (14) and uracil (15). Structures were elucidated by spectroscopic (NMR and MS) methods and confirmed by comparing with reference samples and literature data. Compounds 1-2, 4-12, 14, and 15 were isolated from this genus for the first time, while this is the first report of coumarinolignoids in the Compositae family, and coumarinoligoids could be considered as valuable chemotaxonomic markers for the plant.     

Synthetic transformations of sesquiterpene lactones: VII. Palladium-catalyzed cross-coupling of isoalantolactone with 5-halouracils

Palladium-catalyzed cross-coupling of isoalantolactone with 1,3-disubstituted or 1-substituted 5-bromo(iodo)uracils afforded mainly (13E)-13-(2,4-dioxotetrahydropyrimidin-5-yl)eudesma-4(15),11(13)-dien-8β,12-olides whose yields depended on the composition of the catalytic system, base, and additive. The structure of (13E)-13-[3-(2-cyanoethyl)-2,4-dioxotetrahydropyrimidin-5-yl]eudesma-4(15),11(13)-dien-8β,12-olide was proved by X-ray analysis.     

Photosensitized Oxygenation of Abieta-7,9(11)-dien-13β-ol

Dehydration of abiet-8-ene-7β, 13β-diol (ibozol, 1 ) leads to abieta-7,9(11)-dien-13β-ol ( 2 ) which aromatizes slowly to the known abieta-8,11,13-triene ( 3 ). Photosensitized oxygenation of the heteroannular diene 2 yields a mixture from which three compounds were identified; abiet-7-ene-9α, 11α, 13β-triol ( 4 ), abieta-8,11,13-trien-7-one ( 5 ), and abieta-8,11,13-trien-7α-ol ( 6 ).     

Tetracyclic triterpenoids isolated from semi-mangrove plant Hibiscus tiliaceus

A continuing phytochemical study on the semi-mangrove plant Hibiscus tiliaceus yielded two new tetracyclic triterpenoids （3β,24S）-19（10→9）-abeo-8α,9β,10α-eupha-5,25（26）-dien-3,24-diol （tiliacol A, 1 ）, and （3β,23Z）-19（10→9）-abeo-8α,9β,10α-tircalla-5,23-dien-3,25-diol （tiliacol B, 3）, together with one known analog （2）. Their structures were elucidated on the basis of extensive spectral analyses （MS, IR, 1D NMR and 2D NMR） and comparison with literature compounds. Compound 2 showed potent cytotoxicity against both P388 and HeLa cells with ICon values of 11.2 μmol/L and 11.5 μmol/L, resoectively.     

Clerodane diterpenoids from Microglossa angolensis

Two new diterpenoids, 6β-(2-methylbut-2(Z)-enoyl)-3α,4α,15,16-bis-epoxy-8β,10βH-ent-cleroda-13(16),14-dien-20,12-olide and 10β-hydroxy-6-oxo-3α,4α,15,16-bis-epoxy-8βH-cleroda-13(16),14-dien-20,12-olide, together with the known β-amyrin, spinasterol, 5,7-dihydroxy-3,8,3′,4′-tetramethoxyflavone and 5,7-dihydroxy-3,8,3′,4′,5′-pentamethoxyflavone have been isolated from the aerial parts of Microglossa angolensis Oliv. et Hiern (Compositae). The structures were elucidated on the basis of spectral studies and comparison with published data.     

Ilwensisaponins A,B, C,and D: Triterpene Saponins from Scrophularia ilwensis

From the aerial parts of Scrophularia ilwensis, four new triterpene saponins, ilwensisaponins A–D ( 1 – 4 ) were isolated. The structures of the compounds were elucidated using chemical and spectral data as 13β, 28-epoxy-3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}-oxy} olean-11-en-23-ol ( 1 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olena-11, 13(18)-diene-23, 28-diol ( 2 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D glucopyranosyl-(1→3)]-β-D fucopyranosyl}oxy}-11α-methoxyolean- 12-ene-23, 28-diol (3) , and 3-β-{{[β-D -glucopyransoyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olean-12-ene-11α,23,28-triol (4) .