Ian-Lih Tsai

Coumarins and anti-platelet aggregation constituents from Zanthoxylum schinifolium

Six new coumarins, schinicoumarin, acetoxyaurapten, epoxycollinin, schininallylol, schinilenol and schinindiol, along with seven known coumarins, aurapten, collinin, epoxyaurapten, hydrangetin, umbelliferone, acetoxycollinin and aesculetin dimethyl ether, three known alkaloids, norchelerythrine, dictamnine and skimmianine, and two triterpenoids, beta-amyrin and friedelin, were isolated and characterized from the chloroform-soluble part of the bark of Zanthoxylum schinifolium. The structures of these compounds were elucidated by spectral analyses. Separation accompanied by bioassay-guided fractionation resulted in the isolation of seven compounds with strong inhibitory activity on platelet aggregation in vitro. These are schinicoumarin, acetoxyaurapten, schininallylol, aurapten, collinin, (-)-acetoxycollinin and dictamnine.

Anti-platelet aggregation constituents from formosan Toddalia asiatica

Examination on the wood of Formosan Toddalia asiatica led to the isolation of 30 compounds, including coumarins, alkaloids, a benzoquinone and an amine. Among the isolates, (+/-)-toddanin and (-)-isocoreximine are new compounds, while cyclohexylamine was isolated for the first time from nature. The structures of the compounds were elucidated from spectroscopic data and chemical evidence. Bioassay-guided fractionation led to the isolation of seven compounds showing strong anti-platelet aggregation activity in vitro.

Chemical and anti-platelet constituents from Formosan Zanthoxylum simulans

A pyrrole alkaloid, pyrrolezanthine [5-hydroxymethyl-1-[2-(4-hydroxyphenyl)-ethyl]-1H-pyrrole-2-carbaldehyde]; a lignan, (-)-simulanol [4- [3-hydroxymethyl-5-((E)-3-hydroxypropenyl)-7-methoxy-2,3-dihydrobenzofuran-2-yl]-2,6-dimethoxy-phenol] and a monocyclic gamma-pyrone, zanthopyranone [3,5-dimethoxy-2-methyl-pyran-4-one], together with 28 known compounds were isolated from the stem wood of Formosan Zanthoxylum simulans. Their structures were determined through spectral analyses. Among the isolates, 11 compounds showed anti-platelet aggregation activity in vitro.

Coumarins and anti-HBV constituents from Zanthoxylum schinifolium

Abstract Continuing examination on the chloroform-soluble part of the bark of Zanthoxylum schinifolium , two new terpenyl coumarins, 7-(5′,6′-dihydroxy-3′,7′-dimethylocta-2′,7′-dienyloxy)-coumarin and 7-(2′,6′-dihydroxy-7′-methyl-3′-methyleneocta-7′-enyloxy)-8-methoxycoumarin, along with three coumarins, anisocoumarin H, 7-[( E )-7′-hydroxy-3′,7′-dimethylocta-2′,5′-dienyloxy]-coumarin, scopoletin; two alkaloids, 4-methoxy-1-methyl-2-quinolone and oxynitidine and a lignan, (+)-matairesinol, were isolated as additional constituents. The structures of these compounds were elucidated by spectral analyses. Among the isolates of the bark, collinin and oxynitidine showed significant activity of anti-HBV DNA replication.

Constituents of the Root Wood of Zanthoxylum wutaiense with Antitubercular Activity

Bioassay-guided fractionation of the root wood of Zanthoxylum wutaiense led to the isolation of 11 new compounds, wutaiensol methyl ether (1), demethoxywutaiensol methyl ether (2), methyl wutaiensate (3), methyl 7-hydroxyanodendroate (4), methyl 7-methoxyanodendroate (5), wutaifuranol (6), 7-methoxywutaifuranol (7), 7-methoxywutaifuranal (8), methyl wutaifuranate (9), methyl 7-methoxybenzofuran-5-carboxylate (10), and wutaipyranol (12), together with another 37 known compounds, of which one, 7-methoxybenzofuran-5-carboxaldehyde (11), was not previously known as a plant constituent. The structures of these isolates were identified by means of spectroscopic analysis. Five of these isolates were found to be antitubercular constituents, namely, methyl 7-methoxyanodendroate (5), 7-methoxywutaifuranal (8), wutaiensal (13), dictamnine (14), and gamma-fagarine (15), which exhibited antitubercular activity against Mycobacterium tuberculosis H37Rv, showing MIC values of 35, 35, 30, 30, and 30 microg/mL, respectively.

Cytotoxic butanolides from Litsea akoensis

Abstract Four new butanolides, akolactone A, akolactone B, litseakolide A and litseakolide B, along with four known butanolides, litsenolide B 2 , litsenolide C 1 , litsenolide C 2 and hamabiwalactone A were isolated from the stem bark of Litsea akoensis . Their structures were elucidated from spectral evidence. These butanolides showed cytotoxic activity against P-388, KB16, A 549 and HT-29 cancer cell lines.

N-cyclohexyl amides and a dimeric coumarin from formosan Toddalia asiatica

Abstract Examination of the root wood of Formosan Toddalia asiatica led to the isolation of four N -cyclohexylamides: N , N ′-dicyclohexyloxamide, N , N ′-dicyclohexylurea, toddaliamide, methyltoddaliamide; one dimeric coumarin: toddasiatin; and six alkaloids: skimmianine, norchelerythrine, oxyavicine, avicine, oxynitidine and nitidine, from the tertiary non-phenolic basic fraction. Toddaliamide, methyltoddaliamide and toddasiatin are new compounds while N , N ′-dicyclohexyloxamide and N , N ′-dicyclohexylurea were isolated for the first time from nature. The structures of all the compounds were elucidated by spectral data and chemical evidence.

Cytotoxic neolignans from Persea obovatifolia

Abstract Three new formyl neolignans, including obovatinal [(2S,3S)-2,3-dihydro-2-(4,5-dimethoxy-3-hydroxy-phenyl)-5-formyl-7-methoxy-3-methyl benzofuran], preseal A and perseal B (erythro- and threo- 1-(4-hydroxy-3-methoxyphenyl)-2-(4-formyl-2-methoxyphenoxy) propan-1-ol) were isolated and characterized from the leaves of Persea obovatifolia. The structures of these compounds were elucidated from spectral evidence. The new neolignans all showed significant cytotoxicity against P-388, KB16, A549 and HT-29 cancer cell lines.

Cytotoxic Constituents From the Leaves of Litsea Akoensis

Six butanolides, akolactone A (1), akolactone B (2), a mixture of 1 and akolactone C (3), litseakolide B (4), litsenolide B2 (5), litsenolide C2 (6), together with β-sitosterol, methylparaben, ρ-hydroxybenzaldehyde, veratric acid (7), α-tocopherol (8), α-tocopherol quinone (9), methyl oleate, methyl linoleate, methyl linolenate, a mixture of ficaprenol-10 (10) and ficaprenol-11 (11) 2,6,11-trimethyldodeca-2,6,10-triene, stearic acid, palmitic acid, a mixture of I-tetracosanol and 1-hexacosanol, and trans-phytol (l2) were obtained from the leaves of Litsea akoensis. 3 is a new compound. The cytotoxicity and structures of these compounds were determined by spectral analyses.

Isobutylamides from the fruit of Zanthoxylum integrifoliolum

Abstract Investigation of the fruit of Zanthoxylum integrifoliolum led to the isolation of three new isobutylamides, lanyuamide I–III and six known isobutylamides, tetrahydrobungeanool, γ-sanshool, hydroxy γ-sanshool, mixture of (2E,4E,8Z,11E)- and (2E,4E,8Z,11Z)-2′-hydroxy-N-isobutyl-2,4,8,11-tetradecatetraenamide and hazaleamide which was mixed with lanyuamide III. These amides were all with a (2E,4E)-dienamide moiety and their structures were elucidated on the basis of spectral analyses.