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Three new (8, 12, 13) and two revised (7, 9) eudesmane alcohols have been identified from the Taiwanese liverwort Lepidoziafauriana, together with a known macrocyclic bisbibenzyl, isoplagiochin D, and other known sesquiterpenoids. Their structures were determined by NMR and X-ray analyses. Three chemo-types of Lepidoziafauriana may be classified according to the skeleton of the major sesquiterpenoids identified in the species.

The sesquiterpene constituents of the essential oils of the Taiwanese liverworts Lepidozia fauriana and L. vitrea were investigated. 11,12-Dihydrochiloscyphone and 7,10-anhydro-11,12-dihydrochiloscypholone were isolated from L. fauriana and spectroscopically characterised together with their hydrogenation products. From the same species three amorphane derivatives amorpha-4,9-dien-14-al, amorpha-4,9-dien-2-ol and 7,14-anhydroamorpha-4,9-diene, and from L. vitrea two oxygenated elemanes, namely 7-acetoxy-elema-1,3-dien-8-ol and elema-1,3-dien-7-ol, were isolated and identified. Structure elucidation was carried out by NMR spectroscopy and chemical correlations in conjunction with enantioselective gas chromatography were utilized to establish absolute configurations.

Two minor diterpenoids, 15(16)-peroxy-3, 13-clerodadien-18-oic acid (4) and totarol (7), were isolated from the liverwort Schistochila acuminata. The former is a further oxidized cyclic peroxide from the major component. The latter is a rearranged abietane alcohol which skeleton was found in liverworts for the first time.

Neopallavicinin (2), a diastereomer of pallavicinin (1), was identified from the Taiwanese liverwort Pallavicinia subciliata. The structure of neopallavicinin was deduced by spectroscopic analysis. Three chemotypes may be classified for the species Pallavicinia subciliata.

Two Taiwanese liverworts, Jungermannia appressifolia and J. infusca , were chemically investigated. Jungermannia appressifolia elaborated two new labdane-type diterpenoids, labda-7,14-dien-9,13-diol and 13-hydroxy-7-oxo-labda-8,14-diene, along with the known labda-8,14-dien-13-ol. Jungermannia infusca produced two macrocyclic bis(bibenzyls), marchantin C and riccardin C, as its major constituents demonstrating the fourth chemo-type of this complex species.

Commercial Sep-Pak cartridges (Si or C 18 ) with a piece of short PTFE tubing could be used directly without any cooling or heating as a convenient and efficient collection device for preparative gas chromatography. Four sets of experimental results are presented.

The sesquiterpene aldehyde, tridensenal, of previously unknown skeleton was isolated from the Taiwanese liverwort Bazzania tridens. The structure of tridensenal was elucidated on the basis of spectral data and proved by synthesis of the diastereomeric mixture.

The essential oils and extracts of Mylia taylorii and M. nuda were investigated by gas chromatography, mass spectrometry, NMR spectroscopy and chemical correlations. Beside several known compounds 13 new constituents including three new carbon skeletons could be identified. Four hydrocarbons with a molecular formula of C 15 H 22 ( m / z 202) were identified as myli-4(15)-ene ( 1 ), aromadendra-1(10),4(15)-diene ( 19 ), aromadendra-4,10(14)-diene ( 20 ) and aromadendra-4,9-diene ( 21 ). Three oxaspiro-compounds were identified as 7- epi -bourbon-3-en-5,11-oxide ( 22 ), guai-3,10(14)-dien-5,11-oxide ( 23 ) and guai-3,9-dien-5,11-oxide ( 24 ). The absolute configuration of myli-4(15)-en-3-one ( 5 ) could be established by chemical correlation. Together with α-taylorione ( 7 ) the corresponding 6,11- seco -compound taylopyran ( 25 ) with a new carbon skeleton was identified which serves as a precursor to taylocyclane ( 26 ) and taylofuran ( 27 ). Taynudol ( 28 ) contains a new carbon skeleton with a cyclobutenyl structure.

One naphthalene and three isocoumarin derivatives have been isolated from the Taiwanese liverwort Wettsteinia inversa . Their structures were determined by extensive spectroscopical analysis. The significance from the chemotaxonomical point of view is discussed. In addition, the isocoumarin inversin displayed potent antiplatelet activities.

A novel gymnomitrane-type alcohol was identified from the liverwort Cylindrocolea recurvifolia. The structure of this new compound was confirmed by X-ray analysis. This is the first report on the chemical constituents of this genus.

The new sesquiterpene hydrocarbon, cyclomyltaylane, has been isolated from the Taiwanese liverwort Bazzania tridens. Its structure was deduced mainly from various 1D and 2D NMR data.

Nudenoic acid, a new sesquiterpene possessing a novel tricyclic skeleton, was isolated from a Taiwanese liverwort Mylia nuda. The structure of nudenoic acid was determined by spectroscopic means and X-ray analysis.

Two diterpenoids, (+)-labda-7,14-dien-13-ol and (+)-manoyl oxide, and one bis(bibenzyl) compound, isomarchantin C, were isolated as the major components from the Taiwanese liverwort Mylia nuda. The spectral evidence is discussed in this paper. In addition, several monoterpenes and sesquiterpenes were also identified by GC/MS.

By spectral properties and chemical correlation, the structures of two related new sesquiterpenes, isobazzanene and isocyclobazzanene, were proposed to be 1 and 2 , respectively.