Bis-sesquiterpene from the Marine Sponge Dysidea fragilis

Two new sesquiterpenes and one new bis-sesquiterpene, named dysinidins C-E (1-3) along with three known sterols, dysideasterol F, 9α,l lα-epoxycholest-7-en-3β,5α,6α-triol, and 9α,11α-epoxycholest-7-en-3β,5α,6α,19-tetrol 6-acetate (4-6) were isolated from the Vietnamese marine sponge Dysidea fragilis (Montagu, 1814). Their structures were determined by 1D- and 2D-NMR spectroscopies and HR-ESI-MS, as well as by comparison with reported literature data. Compounds 4-6 were found to inhibit eight human cancer cell lines (KB, LU-1, HL-60, LNCaP, SK-Mel-2, HepG-2, MCF-7, and PC-3), with IC50 values ranging from 7.3 to 31.5 µM.

Antcin K, an Active Triterpenoid from the Fruiting Bodies of Basswood-Cultivated Antrodia cinnamomea, Inhibits Metastasis via Suppression of Integrin-Mediated Adhesion, Migration, and Invasion in Human Hepatoma Cells

Previous research demonstrated that the ethyl acetate extract from Antrodia cinnamomea suppresses the invasive potential of human breast and hepatoma cells, but the effective compounds are not identified. The main bioactive compounds of A. cinnamomea are ergostane-type triterpenoids, and the content of antcin K is the highest. The objective of this study was to evaluate the antimetastatic activity and mechanisms of antcin K purified from the fruiting body of basswood-cultivated A. cinnamomea on human liver cancer Hep 3B cells. The results showed that adhesion, migration, and invasion of Hep 3B cells were effectively inhibited by antcin K within 24 h of treatment. Antcin K not only reduced the protein expression and activity of MMP-2 and MMP-9 but also down-regulated vimentin and up-regulated E-cadherin in Hep 3B cells. In depth investigation for the molecular mechanism revealed that antcin K could reduce the protein expression of integrin β1, β3, α5, and αv and suppress phosphorylation of FAK, Src, PI3K, AKT, MEK, ERK, and JNK. These results suggested that antcin K was able to inhibit the metastasis of human hepatoma cells through suppression of integrin-mediated adhesion, migration, and invasion. Coupled with these findings, antcin K has a good potential to reduce the risk of liver cancer metastasis.

Studies on chemical constituents of Ophiopogon japonicus

Two new and six known steroidal glucosides were isolated from the tuber of Ophiopogon japonicus. The new steroidal glucosides were established as (20R,25R)-26-O-β-d-glucopyranosyl-3β,26-dihydroxycholest-5-en-16,22-dioxo-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside (1) and 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β,14α,17α,22α,26-pentaol-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside (3) on the basis of spectroscopic data as well as chemical evidence.

Cytotoxic 5α,8α-epidioxy sterols from the marine sponge Monanchora sp

Three new sterols, 5α,8α-epidioxy-24-norcholesta-6,9(11),22-trien-3β-ol (1), 5α,8α-epidioxy-cholesta-6,9(11),24-trien-3β-ol (2), and 5α,8α-epidioxy-cholesta-6,23-dien-3β,25-diol (3), with four known sterols (4-7) were isolated from a marine sponge Monanchora sp. Their chemical structures were elucidated by extensive spectroscopic analysis. Compounds 1 and 3-7 showed moderate cytotoxicity against several human carcinoma cell lines including renal (A-498), pancreatic (PANC-1 and MIA PaCa-2), and colorectal (HCT 116) cancer cell lines.

Chemical characterization of a commercial Commiphora wightii resin sample and chemical profiling to assess for authenticity

The gum resin of Commiphora wightii [(Hook. ex Stocks) Engl.] is an ayurvedic medicine for the treatment of arthritis, inflammation, obesity, lipid disorders, and cardiovascular diseases and is known as guggul. Morphologically, it is not easy to distinguish guggul from closely related gum resins of other plants. Reliability of the commercially available guggul is critical due to the high risk of adulteration. To check authenticity, a commercial guggul sample was investigated for its chemical markers and 17 metabolites were identified, including three new, 20(S),21-epoxy-3-oxocholest-4-ene (1), 8 β-hydroxy-3,20-dioxopregn-4,6-diene (2), and 5-(13' Z-nonadecenyl)resorcinol (17) from the ethyl acetate soluble part. During the current study, compounds 14- 17 were identified as constituents of Mangifera indica gum, as an adulterant in the commercial guggul sample. This discovery highlighted the common malpractices in the trade of medicinal raw material in the developing world. The structures of the compounds were deduced by the spectroscopic technique and chemical methods, as well as by comparison with the reported data. The structure of 20(S),21-epoxy-3-oxocholest-4-ene (1) was also unambiguously deduced by single-crystal X-ray diffraction technique.

(25S)-cholesten-26-oic acid derivatives from an Indonesian soft coral Minabea sp

(25S)-3-Oxocholesta-1,4-dien-26-oic acid (1) and a new (25S)-18-acetoxy-3-oxocholesta-1,4-dien-26-oic acid (2) were isolated from a soft coral Minabea sp. (cf. aldersladei) collected in North Sulawesi, Indonesia, together with two known cholic-acid-type compounds, 3-oxochol-1,4-dien-24-oic acid (3) and 3-oxochol-4-en-24-oic acid (4). The structures of these compounds were determined on the basis of their spectroscopic data. The absolute stereochemistry at C-25 of 2 was determined by comparative (1)H NMR study using chiral anisotropic reagents [(S)- and (R)-phenylglycine methyl esters]. This is the first to report compound 1 as a natural product.

[Studies on chemical constituents of Laurencia tristicha ( II )]

OBJECTIVE

To search for chemical constituents with structural diversity from Laurencia tristicha to supply for biological assay.

METHOD

Compounds were isolated by means of column chromatography over normal phase silica gel and Sephadex LH-20, recrystallization and HPLC. Structures were identified by spectroscopic methods including 1D NMR, IR and MS. Cytotoxicities of the purified compounds were evaluated by MTT method.

RESULT

Seven compounds were isolated from L. tristicha. Their structures were elucidated as cholesterol (1), cholesta- 5-en-3beta, 7alpha-diol (2), beta-stigmasterol (3), phytol (4), zeaxanthin (5), 4 -hydroxybenzaldehyde (6), indolyl-3-carbaldehyde (7). In the cytotoxic assay compound 2 was active against human cancer cell lines HCT-8, Bel-7402, BGc-823, A549 and HELA with IC50 values of 1.90, 2.02, 1.99, 6.52 and 1.20 microg x mL(-1), respectively. Compound 4 showed cytotoxicity against HCT-8 and HELA with IC50 value of 3.51 and 2.04 microg x mL(-1), and other compounds were inactive ( IC50 > 10 microg x mL(-1)).

CONCLUSION

Compounds 1-7 were isolated from L. tristicha for the first time. In additon, compounds 2 and 4 were cytotoxic against several human cancer cell lines.

Purification of dinosterol for hydrogen isotopic analysis using high-performance liquid chromatography-mass spectrometry

A semi-preparative normal-phase high-performance liquid chromatography-mass spectrometry (HPLC-MS) method is presented for the purification of various alcohol fractions from total lipid extracts derived from sediments, for the purpose of hydrogen isotopic measurement by gas chromatography-isotope ratio mass spectrometry (GC-IRMS). 4-methylsterols, including the dinoflagellate-specific marker dinosterol (4,23,24-trimethylcholestan-22-en-3beta-ol), were successfully separated from notoriously co-eluting plant-derived pentacyclic triterpenoid alcohols and alkyl alcohols. We find that substantial hydrogen isotope fractionation occurs during chromatographic separation, demonstrating the importance of recovering the entire peak when subsequent hydrogen isotope analyses are to be performed. This is the first report of such hydrogen isotopic fractionation for a natural unlabelled compound.

[Steroid compounds from the Far East starfish Pteraster obscurus and the ophiura Asteronyx loveni]

Seven sulfated polyhydroxysteroids were isolated from the Far East starfish Pteraster obscurus and the ophiura (snake star) Asteronyx loveni (collected in the Sea of Okhotsk) and characterized: disodium and sodium salts of (20R)-24-methyl-2beta-hydroxycholesta-5,24(28)-diene-3alpha,21-diyl disulfate, (20R)-5alpha-cholestane-3beta,21-diyl disulfate, (20R)-3beta-hydroxy-5alpha-cholestan-21-yl sulfate, (20R)-cholest-5-ene-3beta,21-diyl disulfate, (20R)-2beta-hydroxycholest-5-ene-3alpha,21-diyl disulfate, (20R)-cholest-5-en-3beta-yl sulfate, and (20R)-5alpha-cholestan-3beta-yl sulfate. The first four compounds turned out to be new, whereas the others were identical to the known compounds. Structures of the isolated steroids were identified by two-dimensional NMR spectroscopy and other physicochemical methods. The compounds isolated from starfish are structurally similar to typical ophiuroid metabolites, which support the opinion of some taxonomists that starfish and ophiuroids are phylogenetically related classes.

[Trofosides A and B and other cytostatic steroid-derived compounds from the Far East starfish Trofodiscus über]

Three new polar steroids identified as trofoside A, (20R,24S)-24-O-(3-O-methyl-beta-D-xylopyranosyl)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, its 22(23)-dehydro derivative (trofoside B), and 15-sulfoxy-(20R,24S)-5alpha-cholestane-3beta,6beta,8,15alpha,24-pentaol sodium salt, were isolated from Trofodiscus uber starfish extracts collected in the Sea of Okhotsk. Two known compounds, trofoside A aglycone, (20R,24S)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, and triseramide, (20R,24R,25S,22E)-24-methyl-3beta,6alpha,8,15beta-tetrahydroxy-5alpha-cholest-22-en-27-oic acid (2-sulfoethyl)amide sodium salt, were also found. The structures of the isolated polyoxysteroids were established from their spectra. Minimal concentrations causing degradation of unfertilized egg-cells of the sea-urchin Strongylocentrotus intermedius (C(min)) and terminating the cell division at the stage of the first division (C(min) embr.), as well as the concentrations causing 50% immobilization of sperm cells (ImC50) and inhibiting their ability to fertilize egg-cells by 50% (IC50) were determined for the isolated compounds. Of three compounds highly toxic in embryos and sea-urchin sperm cells, the polyol with a sulfo group in the steroid core was the most active; two glycosides with monosaccharide chains located at C3 and C24 atoms were less toxic. Note that all the compounds with the spermiotoxic activities differently affected the embryo development. The positions of monosaccharide residues in the core considerably influence the compound activity. For example, both mono- and double chained glycosides with the monosaccharide fragment at C3 and C24 atoms are active against sea-urchin sperm cells and embryos, whereas the C24 glycosylated trofoside A does not affect embryos and displays a poor spermiotoxicity.

Structural identification of an anthrasteroid hydrocarbon from the sheep tick Ixodes ricinus

A new anthrasteroid hydrocarbon was isolated from cuticular integument of engorged female Ixodes ricinus, and its structure was determined by interpretation of spectroscopic and nuclear magnetic resonance data as 14alpha(H)-1(10-->6)-abeo-cholesta-3,5,7,9(10)-tetraene (1).

[Isolation and structure identification of C-25 epimers of inokosterone from Achyranthes bidentata Blume]

AIM

To isolate C-25 epimers of inokosterone from Achyranthes bidentata Blume. and identify their structures.

METHODS

To separate C-25 epimers of inokosterone by using various kinds of chromatography methods and identify their structures on basis of spectral analysis and chemical method.

RESULTS

Three compounds were isolated and their structures were established as 25S-inokosterone (1), 25R-inokosterone (2) and ecdysterone (3).

CONCLUSION

Compounds 1 and 2 are new C-25 configuration isomers from Achyranthes bidentata Blume., their absolute configurations are elucidated at the first time, and their 13CNMR data are reported for the first time.

New cytotoxic steroids from the Indian Ocean sponge Axinella cf. bidderi

Four new sterols have been isolated from the marine sponge Axinella cf. bidderi, 17alpha-hydroxy-22,23-epoxy-24-methylcholest-5-en-3beta-ol (1) and 17alpha-hydroxy-22,23-epoxycholest-5-en-3beta-ol (2), together with 3 and 4, which possess respectively the cholestene and the cholestane skeleton with a cyclic enol ether linkage between C-18 and C-22. The structures were elucidated using spectroscopic data. The in vitro activity was evaluated against prostate, ovary, pancreas, colon, and lung cell lines.

Reversal of fluconazole resistance in multidrug efflux-resistant fungi by the Dysidea arenaria sponge sterol 9alpha,11alpha-epoxycholest-7-ene-3beta,5alpha,6alpha,19-tetrol 6-acetate

The sponge sterol 9alpha,11alpha-epoxycholest-7-ene-3beta,5alpha,6alpha,19-tetrol 6-acetate (ECTA) (1) is the first marine natural product to reverse fluconazole resistance mediated by a Candida albicans MDR efflux pump. The IC(50) of fluconazole is decreased from 300 to 8.5 microM (35-fold enhancement) when combined with 1(3.8 microM). A revised C-6 configuration of 1 is established.

A new spiroketal steroid from Gorgonella umbraculum

A new spiroketal steroid (2) was isolated from the Indian Ocean gorgonian, Gorgonella umbraculum besides the known briarane diterpenoids, juncellin, umbraculides A and D. The new steroid was characterised as 22-acetoxy-3,25-dihydroxy-16-24,20-24-bisepoxy-(3beta, 16alpha, 20S, 22R, 24S)cholest-5-ene (2) by a study of its spectral data.

Ecdysteroids from a Zoanthus sp

A new ecdysteroid, zoanthusterone, has been isolated from a marine zoanthid, Zoanthus sp. Ten known ecdysteroids, ponasterone A, 20-hydroxyecdysone 2-acetate, viticosterone E, integristerone A 25-acetate, 2-deoxy-20-hydroxyecdysone, ecdysone, ajugasterone C, dacryhainansterone, inokosterone, and 20-hydroxyecdysone, have also been isolated. This is the first report of ecdysteroids in a Zoanthus species.

From brain to bile. Evidence that conjugation and omega-hydroxylation are important for elimination of 24S-hydroxycholesterol (cerebrosterol) in humans

The brain is the almost exclusive site of formation of 24S-hydroxycholesterol in man, and there is a continuous flux of this oxysterol across the blood-brain barrier into the circulation. The hepatic metabolism of 24S-hydroxycholesterol was studied here by three different approaches: incubation of tritium-labeled 24S-hydroxycholesterol with human primary hepatocytes, administration of tritium-labeled 24S-hydroxycholesterol to a human volunteer, and quantitation of free and conjugated 24S-hydroxycholesterol and its neutral metabolites in ileocecal fluid from patients with ileal fistulae. 24S-Hydroxycholesterol as well as 24R-hydroxycholesterol were converted into bile acids by human hepatocytes at a rate of about 40% of that of the normal intermediate in bile acid synthesis, 7 alpha-hydroxycholesterol. There was also a conversion of 24S-hydroxycholesterol into conjugate(s) of 5-cholestene-3 beta,24S,27-triol at a rate similar to the that of conversion into bile acids. When administered to a human volunteer, labeled 24S-hydroxycholesterol was converted into bile acids at about half the rate of simultaneously administered labeled 7 alpha-hydroxycholesterol. Free, sulfated, and glucuronidated 24S-hydroxycholesterol and 5-cholestene-3 beta,24,27-triol were identified in ileocecal fluid. The excretion of these steroids was about 3.5 mg/24 h, amounting to more than 50% of the total estimated flux of 24S-hydroxycholesterol from the brain. It is concluded that 24S-hydroxycholesterol is a less efficient precursor to bile acids and that about half of it is conjugated and eliminated in bile as such or as a conjugate of a 27-hydroxylated metabolite. The less efficient metabolism of 24S-hydroxycholesterol may explain the surprisingly high levels of this oxysterol in the circulation and is of interest in relation to the suggested role of 24S-hydroxycholesterol as a regulator of cholesterol homeostasis.

[Isolation and identification of two novel polyhydroxylated sterol from Spongia obligue]

Two novel sterols have been isolated from Spongia obligue collected from South China sea and their structure were identified as 24(28)-methylene-1,3,4,11-tetrohydroxycholest-5-en-18-oic acid and 24(28)-methylene-cholestene-5-en-1,3,8,11-tetraol respectively on the basic of the spectral data of MS, IR, 1HNMR and 13CNMR(DEPT).

Chemical constituents of Pseudopterogorgia species of the Indian ocean

A new ceramide, (2S,3R,4E)-1,3-dihydroxy-2-[(hexadecanoyl)amino]-nonadeca-4-ene (1), cholest-5-en-3beta,7beta,19-triol (2), identified as its, peracetyl derivative (3), and batyl alcohol (4) were isolated from Pseudopterogorgia species. 1 exhibited antibacterial activity against Gram-positive and Gram-negative bacteria.

A new cytotoxic polyhydroxysterol from soft coral Sarcophyton trocheliophorum

A new cytotoxic polyhydroxysterol, 23,24-dimethylcholest-16(17)-E-en-3beta,5alpha,6beta,2 0(S)-tetraol (2), together with nine known compounds was isolated from the soft coral Sarcophyton trocheliophorum. Their structures were determined by spectroscopic methods. Compound 2 showed potent growth inhibitory activity against human HL60 leukemia, M14 skin melanoma, and MCF7 breast carcinoma cells with EC50 values of 2.8, 4.3, and 4.9 microg/ml, respectively, and exhibited minimal toxicity to normal human peripheral blood lymphocytes.

A novel antiprotozoal aminosteroid from Saracha punctata

A new aminosteroid, 3beta-amino-22,26-epiminocholest-5-ene named sarachine (1), and two known flavonoids, eriodictyol (2) and 7-O-beta-D-glucopyranosyl-eriodictyol (3), were isolated from the leaves of Saracha punctata. The alkaloid was found to inhibit the growth of Leishmania braziliensis promastigotes (100% at 25 microM) and of Trypanosoma cruzi epimastigotes in culture (50% at 25 microM) and showed a strong in vitro antiplasmodial activity with an IC50 of 25 nM.

Sterol 14-demethylase P450 activity expressed in rat gonads: contribution to the formation of mammalian meiosis-activating sterol

Sterol 14-demethylase P450 (P45014DM)-dependent formation of 4,4-dimethylcholesta-8,14,24-trienol, that has been reported for a mammalian meiosis-activating sterol, in rat ovaries was confirmed. Transient elevation of ovarian P45014DM activity, that might be related to the female sexual cycle of rat, was observed. The P45014DM activity of immature ovaries was induced by pregnant mare's serum gonadotropin. These facts suggest the contribution of ovarian P45014DM to the gonadotropin-dependent formation of the meiosis-activating sterol, and provide a clue to understanding the mechanism how gonadotropins initiate the resumption of meiosis of mammalian oocytes. It was also found that rat testicular P45014DM participated in the production of 4,4-dimethylcholesta-8,24-dienol that was reported for another meiosis-activated sterol isolated from bull testes.

Novel triterpene sulfates from Fusarium compactum using a rhinovirus 3C protease inhibitor screen

Two novel triterpene sulfates have been isolated from Fusarium compactum by bioactivity-directed fractionation using an assay which measures the inhibition of proteolytic activity of rhinovirus 3C protease on a fluorogenic peptide substrate. The compounds were purified by countercurrent and reverse phase chromatographies. NMR, MS, UV and IR studies revealed two triterpene sulfates, uncommon metabolites of terrestrial fungi.

A new cytotoxic sterol methoxymethyl ether from a deep water marine sponge Scleritoderma sp. cf. paccardi

24(R)-Methyl-5 alpha-cholest-7-enyl 3 beta-methoxymethyl ether (1), a new sterol ether, has been isolated from a deep-water marine sponge Scleritoderma sp. cf. paccardi. Compound 1 exhibited in vitro cytotoxicity against the cultured murine P-388 tumor cell line with an IC50 of 2.3 micrograms/mL. The isolation and structure elucidation of 1 by NMR spectroscopy is described.

Sterols from the Caribbean sponge Neofibularia nolitangere. Isolation of two novel polyhydroxysteroids

The sterol composition of the Caribbean sponge Neofibularia nolitangere has been investigated. In addition to usual sterols this sponge elaborates comparable amounts of 24-methylene-4 alpha-methyl-5 alpha-cholest-8-en-3 beta-ol (1), which is very unusual among sponge sterols, and lesser quantities of two new polyoxygenated sterols, (24S)-24-ethyl-5 alpha-cholest-8-ene-5,6 beta,7 alpha-triol (2) and (24S)-24-ethyl-5 alpha-cholest-8(14)-ene-5,6 beta,7 alpha-triol (3).

Potent inhibitors of histamine release: polyhydroxylated sterols from the Okinawan soft coral Sinularia abrupta

A new polyhydroxylated steroid (24-methylene-1 alpha, 3 beta, 11 alpha-trihydroxycholest-5-ene-18-oic acid-3-acetate, 1) and known related compounds (2-4) from the soft coral Sinularia abrupta have potently inhibited histamine release from rat peritoneal mast cells induced by anti-immunoglobulin E. The inhibitory effect of 1 was approximately 6500 times stronger than that of disodium cromoglycate, a well-known antiallergic drug.

New delta 8- and delta 8(14)-5 alpha,6 alpha-epoxysterols from the marine sponge Spongia officinalis

Six new delta 8- and delta 8(14)-5 alpha,6 alpha-epoxysterols (1-6) have been isolated from a collection of the Mediterranean sponge Spongia officinalis. The structures of the new metabolites, isolated as diacetate derivatives, have been determined by spectral analyses and an x-ray diffraction experiment performed on the diacetyl derivative of 1.

Production of a novel steroid sulfate metabolite [4,4,24-trimethylcholesta-8,14,24(28)-trien-2 alpha,3 beta,11 alpha,12 beta-tetrol 12-acetate, 3-sulfate] by Fusarium species and its biological activity

A novel steroid sulfate, 4,4,24-trimethylcholesta-8,14-24(28)-trien-2 alpha,3 beta,11 alpha,12 beta- tetrol 12-acetate, 3-sulfate, was discovered in Fusarium spp. Forty Fusarium strains belonging to F. sporotrichioides, F. chlamydosporum, E. equiseti, F. acuminatum, F. sambucinum, F. culmorum, and F. graminearum produced the steroid on white corn grits at 25 degrees C for 20 days. This steroid sulfate is one of the more abundant and easily attainable microbial steroids. At a concentration of 160 micrograms/ml, it inhibited the growth of six fungi, two gram-positive bacteria, and an alga, as well as the germination of both wheat and tomato seeds.

20-isosterols from the marine bivalve Macoma balthica

A fraction of 20-isosterols has been isolated from the Baltic Sea bivalve Macoma balthica. The main component of this fraction, (20S)-cholest-5-en-3 beta-ol, has been characterized by 300 MHz nuclear magnetic resonance spectroscopy. 20-Isosterols in M balthica probably originate from sea-bottom sediments, an important component of a diet of the animal studied.

Identification of 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one as a product of metabolism of 25-hydroxycholecalciferol by liver microsomes

The ability of liver microsomes, sites of synthesis of 25-hydroxycholecalciferol, to further metabolize 25-hydroxycholecalciferol has been assessed. When liver microsomes were incubated with 25-hydroxycholecalciferol in the presence of cytosol, a metabolite was isolated that comigrated with 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3- one in three different chromatographic systems. The ultraviolet spectrum (220-350 nm) and mass spectrum of the purified metabolite were identical to that of synthetic 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one. This study indicates that liver microsomes convert 25-hydroxycholecalciferol to 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one. The significance of this metabolite, which has been shown previously by others to be produced by alveolar macrophages, has yet to be determined.

Three new 7-keto sterols from the Mediterranean sponge Clathrina clathrus

The CHCl3 extract of the Mediterranean sponge Clathrina clathrus was shown to contain three new sterols: (22 E)-3 beta-hydroxycholesta-5,8,22-trien-7-one (1), (22 E, 24 xi)-3 beta-hydroxy-24-methylcholesta-5,8,22-trien-7-one (2), and (22 E, 24 xi)-3 beta-hydroxy-24-ethylcholesta-5,8,22-trien-7-one (3), whose structures were elucidated on the basis of physico-chemical evidence.

Isolation and structure of a cytotoxic epoxy sterol from the marine mollusc Planaxis sulcatus

A novel epoxy sterol isolated from the marine mollusc Planaxis sulcatus has been identified as 9 alpha,11 alpha-epoxycholest-7-ene-3 beta,5 alpha,6 beta-triol by spectrometric methods.

Inhibitors of sterol synthesis. Reverse phase high performance liquid chromatography for the separation of cholesterol, 5 alpha-cholest-8(14)-en-3 beta-ol-15-one, and their fatty acid esters

A relatively simple and rapid method was required for the separation of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one, a potent inhibitor of sterol synthesis, from its major metabolites. Conditions have been determined which permit the resolution of the 15-ketosterol and cholesterol and fatty acid esters of the two sterols by reverse phase high performance chromatography. This methodology also permits the resolution of the major esters of the 15-ketosterol and of cholesterol.

Isolation, identification, and chemical synthesis of 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one. A new metabolite of 25-hydroxyvitamin D3 produced by mouse myeloid leukemia cells (M1)

It is known that phagocytic cells such as monocyte-macrophages and myeloid leukemia cells metabolize 25-hydroxyvitamin D3 to 10-oxo-19-nor-25-hydroxyvitamin D3. Now we have found that phagocytic cells metabolize 25-hydroxyvitamin D3 not only to 10-oxo-19-nor-25-hydroxyvitamin D3 but also to a new metabolite eluted just after 24R,25-dihydroxyvitamin D3 on straight phase high pressure liquid chromatography with a 2-propanol-hexane solvent system. The new metabolite, produced by murine myeloid leukemia cells (M1), was isolated in pure form and identified as 8,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one on the basis of mass, ultraviolet, infrared, and proton magnetic resonance spectra. The 8 alpha-hydroxy epimer of the putative metabolite was chemically synthesized in two steps starting from 25-hydroxyvitamin D3. The spectral data and chromatographic behavior of chemically synthesized 8 alpha,25-dihydroxy-9,10-seco-4,6,10(19)-cholestatrien-3-one coincided exactly with those of the isolated metabolite, indicating that the stereochemistry of the hydroxyl group at the 8-position is alpha. On the basis of the structural characteristics of the two metabolites produced from 25-hydroxyvitamin D3 (the present metabolite and 10-oxo-19-nor-25-hydroxyvitamin D3), it is suggested that dioxygenases are involved in the production of these metabolites from 25-hydroxyvitamin D3 in phagocytic cells.

Sterols of the cultured euglenid Eutreptia viridis: a novel delta 23-unsaturated sterol

The sterol mixture isolated from the marine alga Eutreptia viridis consists mainly of delta 5,7-dienes which account for 80% of the free sterols. Eighteen different sterols were detected, including a novel sterol with the rare delta 23-unsaturation, viz. 24-ethylcholesta-5,7,23Z-trien-3 beta-o1.

The ecdysteroids from young embryonated eggs of the tobacco hornworm

26-Hydroxyecdysone, which is the major free recoverable ecdysteroid of older age groups of embryonated eggs of the tobacco hornworm was also the major component in 4- to 18-hour-old embryonated eggs. The other 3 beta-ecdysteroids, ecdysone, 20-hydroxyecdysone, and 20,26-dihydroxy-ecdysone, were also present and accounted for all the molting hormone activity; 26-hydroxyecdysone was devoid of molting hormone activity in the house fly assay. 20-Hydroxyecdysone was a minor component, which confirms the earlier observations that the main metabolic route for ecdysteroids during embryonic development is that leading to 26-hydroxyecdysone, whereas formation of 20-hydroxyecdysone is a minor pathway. A new 3 alpha-ecdysteroid, 3-epi-26-hydroxyecdysone, also devoid of molting hormone activity, was the second major ecdysteroid isolated from the eggs. 3-Epi-20,26-dihydroxyecdysone was detected in very minute amounts. In addition to the six 3 beta-and 3 alpha-ecdysteroids there were at least an equivalent number of unknown ecdysteroids all of which lacked molting hormone activity. Their physical properties including chromatographic behavior are discussed.

Characterization of two steroidal ketones and two isoprenoid alcohols in dairy products

Two steroidal ketones, delta-4-cholesten-3-one and delta-3,-5-cholestadiene-7-one, were isolated and identified for the first time in anhydrous milk fat and in nonfat dry milk. Together with these, two isoprenoid alcohols, phytol and dihydrophytol, were identified in anhydrous milk fat. Their identities were established on the basis of chromatographic and mass spectral data and confirmed by comparison with authentic materials.

The isolation of cholest-5-ene-3beta,26-diol from human brain

Cholest-5-ene-3beta,26-diol, isolated from human brain, was further characterized by oxidation to 3-oxocholest-4-en-26-ol and to 3-oxocholest-4-en-26-oic acid. Identification was achieved by comparison (by t.l.c., g.l.c. and g.l.c.-mass spectrometry) with corresponding reference compounds derived from kryptogenin.