New cytotoxic butanolides from Litsea acutivena

Six new compounds, including one nor-neolignan, dehydroxymethylailanthoidol (1), and five butanolides, litseakolide D (2), litseakolide E (3), litseakolide F (4), litseakolide G (5), and isolincomolide D (6), were isolated from the leaves of Litsea acutivena. Their structures were elucidated from spectral analyses. The butanolides (2-6) showed significant cytotoxic activity against P-388, A549, and HT-29 cell lines in vitro.

Cytotoxic butanolides from the stem bark of Formosan Lindera communis

Two new butanolides, lincomolide A (1), lincomolide B (2), along with seven known compounds, isolinderanolide E, sepesteonol, beta-sitosterol, beta-sitosterol-beta-glucoside, tetradecane, nonanoic acid and decanol, were isolated from the chloroform-soluble portion of the stem bark of Lindera communis. Compound 1 showed cytotoxicity against P-388, KB16 and A549, and 2 exhibited cytotoxicity against P-388 cancer cell lines. Moreover, 1 showed marginal activity against HT-29, and 2 against KB16, A549 and HT-29 cancer cell lines. The structures of these compounds were determined by spectral analyses.

Sesquiterpenes from the Formosan stolonifer Tubipora musica

Eight new sesquiterpenes, tubipolides A-G (1-7) and tubiporone (8) (novel carbon skeleton), and a known sesquiterpene, spirotubipolide, have been isolated from the Formosan stolonifer Tubipora musica. The structures of compounds 1-8 were determined by 1D and 2D NMR spectral analysis.

Junceol A, a new sesquiterpenoid from the sea pen Virgularia juncea

A new sesquiterpenoid, junceol A(1), as well as two known diterpenoids, sclerophytin A (2) and cladiellisin (3), have been isolated from the sea pen octocoral Virgularia juncea. The structure of metabolite 1 was determined by extensive spectral analysis. Compounds 1-3 have been shown to exhibit cytotoxicity toward P-388 cancer cells.

Cytotoxic neolignans and butanolides from Machilus obovatifolia

From the chloroform-soluble portion of the stem wood of Machilus obovatifolia, one new neolignan, perseal F (1), four known neolignans, perseal G (2), licarin A, licarin B, acuminatin, two butanolides, linderanolide E and isolinderanolide E, two steroids, beta-sitosterol, beta-sitosterol-beta-D-glucoside, and syringaldehyde were isolated. Perseal F (1) and G (2) are neolignans that have a C-1' formyl side chain instead of a propenyl group. Compound 2 was isolated in a mixture with acuminatin. The structure of 2 was identified by comparison with the product formed by the Lemieux-von Rudloff oxidation of licarin B. Two minor oxidative by-products, 2a and 2b, were also obtained. Linderanolide E showed cytotoxicities against P-388, KB16, A549 and HT-29, 1 against P-388, KB16 and HT-29, and isolinderanolide E against P-388, cancer cell lines, respectively. All structures were identified by means of spectroscopic analyses.

Cytotoxic cyclopenta[b]benzofuran derivatives from the stem bark of Aglaia formosana

A new cytotoxic cyclopenta[b]benzofuran derivative, aglaiformosanin (1) and three known cyclopenta[b]benzofuran derivatives (2 - 4) were isolated from the stem bark of Aglaia formosana. Compounds 1 - 4 exhibited potent cytotoxicity against the P-388, KB, HT-29, HL-60, and A549 cell lines. The structure of compound 1 was determined by spectroscopic analysis.

Cytotoxic dolabellane diterpenes from the Formosan soft coral Clavularia inflata

Six new cytotoxic dolabellane diterpenes, (1R,12R)-dolabella-4(16),7,10-triene-3,13-dione (1), (1R*,7R*,8S*,12R*)-dolabella-4(16),10-diene-7,8-epoxy- 3,13-dione (2), (1R*,10R*,11S*,12R*)-dolabella-4(16),7-diene-10,11-epoxy-3,13-dione (3), (1R)-dolabella-4(16),7,11(12)-triene-3,13-dione (4), (1R*,3R*)-3-hydroxydolabella-4(16),7,11(12)-triene-3,13-dione (5), and (1R*,7R*)-7-hydroperoxydolabella-4(16),8(17),11(12)-triene-3,13-dione (6), have been isolated from the Formosan soft coral Clavularia inflata. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.

Briaexcavatolides K-N, new briarane diterpenes from the gorgonian Briareum excavatum

Four new briarane diterpenes, briaexcavatolides K-N (1-4), along with a known diterpene, 5, have been isolated from the Taiwanese gorgonian Briareum excavatum. The structures of the new metabolites were established by extensive spectral analyses. Furthermore, the structure, including the relative configuration of briaexcavatolide K (1), was confirmed by a single-crystal X-ray analysis. Briaexcavatolides K and L (1 and 2) are the only briarane diterpenes known to possess hydroxyl groups at the C-8beta and C-17alpha positions, respectively. Cytotoxicity of these metabolites toward various cancer cell lines also is described.

Cytotoxic constituents from leaves of Aglaia elliptifolia

Three new cytotoxic compounds, rocagloic acid (1), elliptifoline (2), and elliptinol (3) were isolated from the leaves of Aglaia elliptifolia. The structures of compounds 1-3 were determined by spectral (NMR, MS) and chemical analysis.

New cytotoxic sesquiterpenes from the gorgonian Isis hippuris

Five new suberosane sesquiterpenes, suberosenol A (1), suberosenol B (2), suberosanone (3), suberosenol A acetate (4), and suberosenol B acetate (5), along with the known sesquiterpene subergorgic acid (6), have been isolated from the gorgonian Isis hippuris. The structures of these metabolites were established by spectroscopic and chemical methods. Metabolites 1 and 3-5 were found to exhibit potent cytotoxicity toward P-388, A549, and HT-29 cancer cell lines.

Cytotoxic cembrenolides and steroids from the formosan soft coral Sarcophyton crassocaule

Three new cytotoxic cembrenolide diterpenes, sarcocrassolide (1), crassolide (2), and 13-acetoxysarcocrassolide (3); a known cytotoxic cembrenolide, denticulatolide (4); and two cytotoxic steroids, (24S)-24-methylcholestane-3beta,5alpha,6beta-triol (5) and 24zeta-methylcholestane-3beta,5alpha,6beta,25-te traol-25-monoacetate (6), have been isolated from the Formosan soft coral Sarcophyton crassocaule. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis.

Cytotoxic prenyleudesmane diterpenes from the fruits of Dysoxylum kuskusense

Two new prenyleudesmane diterpenes, dysokusone D (1) and dysokusone E (2), were isolated from the fruits of Dysoxylum kuskusense and exhibited cytotoxicity against P-388, HT-29, and A549 cell lines. Their structures were determined by 1D and 2D NMR spectral analysis.

A cytotoxic lobane diterpene from the formosan soft coral Sinularia inelegans

A new cytotoxic lobane diterpene, ineleganene (1), was isolated from the Formosan soft coral Sinularia inelegans. The structure of compound 1 was determined by 1D and 2D spectral analysis.

Cytotoxic neolignans from the stem wood of Machilus obovatifolia

Four new cytotoxic neolignans, machilusol A (1), machilusol C (3), machilusol D (4), machilusol E (5) as well as two new inactive neolignans, machilusol B (2) and machilusol F (6), were isolated from the stem wood of Machilus obovatifolia. All structures were identified by means of spectroscopic analysis.

Cytotoxic cembrenolide diterpenes from the formosan soft coral lobophytum crassum

A new cytotoxic cembrenolide diterpene, lobocrassolide (1), and a known cytotoxic cembrenolide, lobohedleolide (2), were isolated from the Formosan soft coral Lobophytum crassum. The structure of compound 1 was determined by 1D and 2D spectral analysis.

A cytotoxic 5alpha,8alpha-epidioxysterol from a soft coral Sinularia species

A new sterol, (22R,23R,24R)-5alpha,8alpha-epidioxy-22, 23-methylene-24-methylcholest-6-en-3beta-ol (1), as well as two known sterols, numersterol A (2) and pregnenolone (3), have been isolated from a soft coral Sinularia sp. The structure of metabolite 1 was determined by spectral analysis. Cytotoxicity of sterols 1-3 toward various cancer cell lines is also reported.

Cytotoxic terpenoids from the Formosan soft coral Nephthea brassica

Two new cytotoxic cembranoid diterpenes, brassicolide (1) and brassicolide acetate (2); a new cytotoxic sesquiterpene, (-)-4alpha-O-acetyl-selin-11-en (3); and six cytotoxic terpenoids, (-)-selin-11-en-4alpha-ol (4), 2-hydroxynephthenol (5), nephthenol (6), cembrene A (7), epoxycembrene A (8), and (-)-beta-elemene (9), have been isolated from the Formosan soft coral Nephthea brassica. The structures of compounds 1-9 were determined by spectral, chemical, and X-ray crystallographic analysis.

Excavatolides U-Z, new briarane diterpenes from the gorgonian briareum excavatum

A recent study of the EtOAc extract of the gorgonian Briareum excavatum afforded six new diterpenes of the briarane skeleton, excavatolides U-Z (1-6). The structures and relative stereochemistry of metabolites 1-6 were assigned on the basis of NMR studies and chemical methods. The structure, including the relative configuration of excavatolide U (1), was further confirmed by a single-crystal X-ray analysis. Some of the excavatolides have displayed significant cytotoxicity toward P-388 and HT-29 tumor cells.

New tetrahydroprotoberberine N-oxide alkaloids and cytotoxic constituents of Corydalis tashiroi

Three new tetrahydroprotoberberine N-oxide alkaloids, (-)- cis-corydalmine N-oxide, (-)- trans-corydalmine N-oxide, and (-)- trans-isocorypalmine N-oxide, along with three known benzo[ C]phenanthridine alkaloids, norsanguinarine, dihydrosanguinarine, and oxysanguinarine, six known berberine alkaloids, (-)-tetrahydropalmatine, (-)-corydalmine, (-)-scoulerine, (-)-corynoxidine, (-)-epicorynoxidine, palmatine, and protopine, have been isolated from the herb Corydalis tashiroi. The structures of these compounds were elucidated by spectroscopic analysis. Three of the isolated compounds show significant cytotoxic activities (ED (50) values < 4 microg/ml) against P-388, KB16, A549, and HT-29 cell lines.

Structures and cytotoxicity relationship of isoaaptamine and aaptamine derivatives

A series of 9-O-acylisoaaptamine (3-14) and 4-N-acyl-dihydroaaptamine (16-19) derivatives have been prepared and evaluated for antitumor activity against murine P-388 and human tumor cells including KB16, A549, and HT-29 cell lines. All of compounds showed significant cytotoxicity against P-388 cells. Among them, compounds 9-11 showed potent activity as isoaaptamine (1). There was an apparent lack of linear relationship between cytotoxicity and carbon number of the side chain. The structure and activity relationship for these particular compounds are discussed.

Bioactive sesquiterpenes from a Taiwanese marine sponge Parahigginsia sp

Five new sesquiterpenes, parahigginols A-D (1-4) and parahigginic acid (5), have been isolated from a Taiwanese marine sponge Parahigginsia sp. The structural assignments of the new compounds were based on their spectral data, including 1D and 2D NMR. Biological studies revealed that compounds 2-5 exhibited cytotoxicity against murine P-388 and human KB16, A549, and HT-29 tumor cells.

Excavatolides F-M, new briarane diterpenes from the gorgonian Briareum excavatum

Eight new briarane-type diterpenes, excavatolides F-M (1-8), have been isolated from the gorgonian Briareum excavatum. The structures and relative stereochemistry of these compounds were established by spectral analysis and chemical methods. The cytotoxicity of these compounds toward various cancer cell lines has also been determined.

New cytotoxic oxygenated fucosterols from the brown alga Turbinaria conoides

Fucosterol (1), 24xi-hydroperoxy-24-vinylcholesterol (2), 29-hydroperoxystigmasta-5,24(28)-dien-3beta-ol (3), 24-ethylcholesta-4,24(28)-dien-3-one (4), 24xi-hydroperoxy-24-ethylcholesta-4,28(29)-dien-3-one (5), 24-ethylcholesta-4,24(28)-dien-3,6-dione (6), 24xi-hydroperoxy-24-ethylcholesta-4,28(29)-dien-3,6-di one (7), 6beta-hydroxy-24-ethylcholesta-4,24(28)-dien-3-one (8), and 24xi-hydroperoxy-6beta-hydroxy-24-ethylcholesta-4,28(2 9)-dien-3-one (9) were isolated from the marine brown alga Turbinaria conoides. The structures of these compounds were established by spectral analysis. Isolated for the first time from a natural source, the oxygenated fucosterols 4-9 exhibit cytotoxicity against various cancer cell lines.

Additional cytotoxic neolignans from Persea obovatifolia

Four additional neolignans, comprising obovatifol [(2S,3S)-2,3-dihydro-2- (3,4-dihydroxy-5-methoxyphenyl)-7-methoxy-3-methyl-5-trans-propenyl benzofuran], obovaten [2-(3,4-dihydroxy-5-methoxyphenyl)-7-methoxy-3- methyl-5-trans-propenyl benzofuran], perseal C [(2S,3R)-2,3-dihydro-2-(3,4-methylenedioxyphenyl)-5- formyl-3-hydroxymethyl-7-methoxy benzofuran] and perseal D [2-(3,4-dihydroxy-5-methoxyphenyl)-5-formyl-7- methoxy-3-methyl benzofuran] were isolated in a continuing study of the leaves of Persea obovatifolia. Obovatifol had been reported previously in a mass spectrometric analysis without any other spectroscopic data. Obovaten and perseals C and D are new compounds, bearing a C-1' formyl side-chain, instead of a propenyl group. Their structures were elucidated from spectroscopic data; they showed significant cytotoxic activities against P-388, KB16, A549 and HT-29 cancer cell lines in vitro.

Cytotoxic sterols from the soft coral Nephthea erecta

Two new cytotoxic sterols, 24-methylcholesta-5,24(28)-diene-3beta, 15beta,19-triol (1) and 24-methylcholesta-5,24(28)-diene-3beta, 19-diol-7-one (2), as well as four cytotoxic sterols, 24-methylcholesta-5,24(28)-diene-3beta,19-diol (3), 24-methylcholesta-5,24(28)-diene-3beta,19-diol-7beta-mono aetate (4), 24-methylcholesta-5,24(28)-diene-3beta,7beta,19-triol (5), and 24-methylcholesta-24(28)-ene-3beta,5alpha,6beta,19-tet raol (6), have been isolated from the soft coral Nephthea erecta. The structures of compounds 1 and 2 were determined by spectral analysis.

Novel cytotoxic cembranoids from the soft coral Sinularia flexibilis

Three new cytotoxic cembranoid diterpenes, sinuflexolide (1), dihydrosinuflexolide (2), and sinuflexibilin (3), have been isolated from the soft coral Sinularia flexibilis. The structures of compounds 1-3 were determined by spectral and X-ray crystallographic analysis.

Novel cytotoxic diterpenes, excavatolides A-E, isolated from the Formosan gorgonian Briareum excavatum

The chemistry of Briareum excavatum, a Formosan gorgonian coral, was investigated. This study has led to the isolation of five novel marine natural products, excavatolides A-E (1-5), together with brianolide (6). The structures of the above compounds were established by spectral and chemical methods. The relative configuration of excavatolide B (2) was further confirmed by a single-crystal X-ray structure analysis. Cytotoxicity of these compounds toward various cancer cell lines also is described.

Cytotoxic sterols from the formosan brown alga Turbinaria ornata

Two hydroperoxysterols 24-hydroperoxy-24-vinyl-cholesterol (1) and 29-hydroperoxystigmasta-5,24(28)-dien-3beta-ol (2), and fucosterol (3) were isolated from the brown alga Turbinaria ornata (Sargassaceae). Hydroperoxide 2 is a new natural compound and was converted into 29-hydroxystigmasta-5,24 (28)-dien-3beta-ol (4) by reaction with LAH. Sterols 1, 2, and 4 exhibited cytotoxicity against various cancer cell lines.

Study on cytotoxic oxygenated desmosterols isolated from the red alga Galaxaura marginata

Four novel oxygenated desmosterols, 24 zeta-hydroperoxy-6 beta-hydroxycholesta-4,25-dien-3-one (1), 25-hydroperoxy-6 beta-hydroxycholesta-4,23(E)-dien-3-one (2), 24 zeta-hydroperoxycholesta-4,25-diene-3,6-dione (3), and 25-hydroperoxycholesta-4,23(E)-diene-3,6-dione (4) were isolated from the marine red alga Galaxaura marginata. Steroids 1-4 and three synthetic oxygenated desmosterols 5-7 were shown to exhibit significant cytotoxicity against several cancer cell lines.

Cytotoxic lignans from Formosan Hernandia nymphaeifolia

A new dibenzylbutyrolactone lignan, (--)-6-hydroxyyatein, along with two new furanoid lignans, (--)-hernone [(2R,3S,4R)-(--)-3-hydroxymethyl -4-(3",4",5"-trimethoxybenzoyl)-2-(3,4-dimethoxyphenyl) tetrahydrofuran] and (--)-nymphone [(2R,3S,4R)-(--)-3-hydroxymethyl-4-(3",4",5"-trimethoxybenzoyl)-2- (3,4-methylenedioxyphenyl)tetrahydrofuran], have been isolated and characterized from the trunk bark of Formosan Hernandia nymphaeifolia. The structures of these compounds were determined by means of spectral analyses. These three lignans exhibited cytotoxic activities against P-388, KB16, A549 and HT-29 cell lines.

New aporphine alkaloids and cytotoxic constituents of Hernandia nymphaeifolia

Two new aporphine alkaloids, (+)-N-hydroxyhernangerine (1) and N-formyldehydroovigerine (2) as minor bases, along with four known aporphines, (+)-magnoflorine, (+)-hernovine, (+)-N-methylhernovine, and (+)-laurotetanine, two known isoquinolones, thalifoline and northalifoline, and one benzylisoquinoline, (+)-reticuline, have been additionally isolated from the trunk bark of Hernandia nymphaeifolia. The structures of these compounds were elucidated by spectroscopic evidence. Six of the isolated compounds show significant cytotoxic activities (ED50 values < 1 microgram/ml) against P-388, KB16, A549, or HT-29 cell lines.

New dimeric aporphine alkaloids and cytotoxic constituents of Hernandia nymphaeifolia

Three minor new dimeric aporphine alkaloids, oviisocorydine (1), ovihernangerine (2), and oxohernandaline (3), along with four known alkaloids, (+)-hernandaline, (+)-thallcarpine, (+)-N-methylovigerine, and N-methylcorydaldine, and five known lignans, (+)-epimagnolin, (+)-epiaschantin, (+)-epiyangambin, (-)-deoxypodophyllotoxin, and (-)-yatein, have been additionally isolated from the trunk bark of Hernandia nymphaeifolia. The structures of these compounds were elucidated by spectroscopic methods. Among forty-four isolates obtained till now, nine compounds, hernandonine (4), hernanymphine (5), demethylsonodione (6), (+)-ovigerine (7), (+)-N-methylovigerine (8), N-formyldehydroovigerine (9), 4-methoxyoxohernandaline (10), (-)-deoxypodophyllotoxin (11), and (-)-yatein (12) showed significant cytotoxic activities (ED50 values < 1 microgram/ml) against P-388, KB16, A549, and HT-29 cell lines.

Coumarins and antiplatelet aggregation constituents from Formosan Peucedanum japonicum

Four new khellactone esters, (-)-trans-3'-acetyl-4'-senecioylkhellactone, (+-)-cis-3'-acetyl-4'-tigloylkhellactone, (+-)-cis-4-tigloylkhellactone, (+)-trans-4'-tigloylkhellactone, together with 14 known coumarins, isoimperatorin, psoralen, bergapten, xanthotoxol, cnidilin, (-)-selinidin, (-)-deltoin, (+)-pteryxin, (+)-peucedanocoumarin III, xanthotoxin, imperatorin, (+)-marmesin, (+)-oxypeucedanin hydrate, (+)-peucedanol and three chromones, eugenin, (-)-hamaudol, (+)-visamminol, have been isolated from the root of Formosan Peucedanum japonicum. The structures of the new compounds were elucidated by spectral data. The identities of (+)-trans-3'-tigloyl-4'-acetylkhellactone, formerly reported as a new compound, and (+)-cis-3'-angeloyl-4'-acetyl-khellactone, with the known (+)-peucedanocoumarin III and (+)-pteryxin, respectively, are discussed. Among the isolates, seven compounds, eugenin, (-)-selinidin, (+)-pteryxin, imperatorin, bergapten, cnidilin and (+)-visamminol, show strong antiplatelet aggregation activity in vitro.

Cytotoxic oxygenated desmosterols of the red alga Galaxaura marginata

Desmosterol (1), 24,25-epoxycholesterol (2), 24-hydroperoxycholesta-5,25-dien-3 beta-ol (3), 25-hydroperoxycholesta-5,23(E)-dien-3 beta-ol (4), cholesta-5,25-diene-3 beta,24-diol (5), and 24,25-epoxy-6 beta-hydroxycholest-4-en-3-one (7) were isolated from the marine red alga Galaxaura marginata; sterols 3, 4, and 7 were isolated for the first time from a natural source. Sterols 3-7 exhibited significant cytotoxicity toward several cancer cell lines.

Sinugibberol, a new cytotoxic cembranoid diterpene from the soft coral Sinularia gibberosa

Bioactivity-guided fractionation of a chloroform extract of the soft coral Simularia gibberosa afforded a new cytotoxic cembranoid diterpene, sinugibberol [1]. The structure of 1 was determined by spectral and X-ray crystallographic analysis.

Studies on the acetogenins of Formosan annonaceous plants. II. Cytotoxic acetogenins from Annona reticulata

Using cytotoxicity as a guide to fractionation, one novel acetogenin, annoreticuin-9-one [3], and four known cytotoxic acetogenins, squamone [4], solamin [5], annomonicin [6] and rolliniastatin 2 [7], were isolated from active extracts of the leaves of the Formosan plant Annona reticulata. Their structures were elucidated on the basis of uv, ir, 1H- and 13C-nmr, and ms data of the natural compounds and their derivatives.

Cell-cycle specific cytotoxicity mediated by stizophyllin (2 alpha,3 beta,12 beta-trihydroxypregna-4,7,16-trien-20-one), a novel electrophilic pregnane isolated from Stizophyllum riparium

A structurally-novel pregnane derivative, 2 alpha,3 beta,12 beta-trihydroxypregna-4,7,16-trien-20-one (stizophyllin), was isolated from an extract of Stizophyllum riparium (H.B.K.) Sandw. on the basis of bioactivity-guided fractionation and confirmed to mediate a potent cytotoxic response with cultured P-388 cells. We presently report a detailed isolation procedure and the results of studies designed to examine its mechanism of action. By means of a Michael-type addition, stizophyllin formed adducts with nucleophilic substances such as L-cysteine and beta-mercaptoethanol. The adduct with beta-mercaptoethanol was isolated, structurally characterized, and found to be 20-fold less cytotoxic than stizophyllin. Stizophyllin interacted with DNA, but no mutagenicity was observed with Salmonella typhimurium strain TM677 or cultured Chinese hamster ovary cells, and no in vitro reaction occurred with guanosine. Relative to control cell cultures, the total biosynthesis of DNA, RNA or protein was reduced when P-388 cells were treated with stizophyllin. However, the cell number did not increase in the presence of inhibitory stizophyllin concentrations (e.g., 4 micrograms/ml), and the DNA content (per cell) actually doubled after approximately 48 h. Consistent with this, stizophyllin blocked the cells in the G2 + M compartment of the cycle, and the block appeared to be specific for the G2 phase. Accordingly, stizophyllin did not modulate in vitro tubulin polymerization reactions nor did it affect the morphology of dibutyryl cAMP-treated astrocytoma cells in culture. These data suggest that the cytotoxic activity of stizophyllin is mediated by covalent reaction with a cellular component (such as a sulfhydryl-containing protein) by means of a Michael-type addition. Based on the cell-cycle specificity of the response, it appears that this interaction prevents the cells from progressing through mitosis.