Eremophilane Glucosides from Petasites japonicus

Three new eremophilane glucosides, namely, petasitosides A–C, and seven known eremophilane‐type sesquiterpenoids were isolated from the roots of Petasites japonicus. Their structures were elucidated by spectroscopic techniques including 1D‐ and 2D‐NMR spectroscopy and mass spectrometry. This is the first report on eremophilane glycosides from the genus Petasites.     

Five New Eremophilane Sesquiterpenes from Ligularia przewalskii

Five new eremophilane‐type sesquiterpenes, 3β‐(acetyloxy)‐7‐hydroxynoreremophila‐6,9‐dien‐8‐one ( 1 ), 8β‐hydroxy‐2‐dehydroxyliguhodgsonal ( 2 ), 3β‐(acetyloxy)‐11‐methoxy‐8‐oxoeremophila‐6,9‐dien‐12‐oic acid ( 3 ), 3β‐(acetyloxy)‐11‐(2′‐methylbutanoyloxy)‐8‐oxoeremophila‐6,9‐dien‐12‐oic acid ( 4 ), and 3β‐(acetyloxy)‐6α‐hydroxyligularenolide ( 5 ), along with the three known compounds 6 – 8 , were isolated from the roots of Ligularia przewalskii. The structures of the new compounds were elucidated through spectral studies including HR‐EI‐MS, IR, and NMR data.     

Eremophilane sesquiterenes from the marine fungus Penicillium sp. BL27-2

Six eremophilane sesquiterpenes were obtained from a marine fungus Penicillium sp. BL27-2. Their structures were elucidated as 3-acetyl-9, 7 （11）-dien-7a-hydroxy-8-oxoeremophilane （1）, 3-acetyl-13-deoxyphomenone （2）, Sporogen-AO 1 （3）, 7-hydro- xypetasol （4）, 8a-hydroxy-13-deo -xyphomenone （5） and 6-dehydropetasol （6） based on detailed NMR analysis. 1 was a new compound and 2 was obtained as a new natural compound. These compounds were assayed for their cytotoxic activity on P388, A549, HL60, BEL7402 and K562 cell lines by the MTT method. The assay results suggested the epoxide rings in eremophilane molecules were essential for their activity, and acetylation could enhance their activity.     

Two New Guaiane Sesquiterpenes from the Fruits of Daucus carota

Two new sesquiterpenes, 11‐(acetyloxy)torilolone ( 1 ) and 1β‐hydroxytorilolone ( 2 ) were obtained from the fruits of Daucus carota. Their structures were elucidated on the basis of various spectroscopic analyses and chemical evidence.     

Three Unusual New Sesquiterpenes from Alpinia oxyphylla

Two new norcadinene sesquiterpenes oxyphyllones C and D ( 1 and 2 , resp.), and one new 1,10‐secoguaiane sesquiterpene, (+)‐mandassidion ( 3 ), together with two known compounds, oxyphyllenodiol B ( 4 ) and (1R,2R)‐p‐menth‐3‐ene‐1,2‐diol ( 5 ), were isolated from the fruits of Alpinia oxyphylla. Their structures were determined on the basis of spectroscopic analysis, including 2D‐NMR spectroscopic techniques. Compounds 1, 2 , and 3 exhibited no cytotoxicity against three cancer cell lines.     

Two New Highly Oxidized Humulane Sesquiterpenes from the Basidiomycete Lactarius mitissimus

Two new highly oxidized humulane sesquiterpenes, mitissimols F ( 1 ) and G ( 2 ), were isolated from the fruiting bodies of Lactarius mitissimus. Their structures were elucidated by using extensive spectroscopic techniques including 1D‐ and 2D‐NMR experiments. The absolute configuration of mitissimol F ( 1 ) was determined by ¹H‐NMR resolution of its diastereoisomeric α‐methoxy‐α‐(trifluoromethyl)benzeneacetates (MTPA). It was shown to be (1S,3E,6S,8R,9R,10S,11R)‐8,9 : 10,11‐diepoxy‐1,6‐dihydroxyhumul‐3‐en‐5‐one (=(1S,2R,4R,6S,8E,11S,12R)‐6,11‐dihydroxy‐1,6,10,10‐tetramethyl‐3,13‐dioxatricyclo[10.1.0.0^2,4]tridec‐8‐en‐7‐one).     

Two New Sesquiterpenes from Myrrh

Two new sesquiterpenes, named 9‐methoxymyrrhone ( 1 ) and rel‐(1S,2S,3R,4S)‐1,2‐epoxy‐3‐methoxyfuranogermacr‐10(15)‐en‐6‐one ( 2 ), together with nine known compounds ( 3 – 11 ), were isolated from the resin of Commiphora opobalsamum. The structures were established by HR‐ESI‐MS, 1D‐, and 2D‐NMR spectroscopic analyses.     

New Sesquiterpenes from the Flowers of Chrysanthemum indicum L.

Two new guaianolides (=guaianolactones), chrysanthguaianolactone A and B ( 1 and 2 , resp.), and one new eudesmane sesquiterpene, chrysanthemdiol A ( 6 ), together with seven known sesquiterpenes were isolated from the flowers of Chrysanthemum indicum L. Their structures were elucidated on the basis of spectroscopic evidence.     

Two New Sesquiterpenes from Ligularia Duciformis

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New Sesquiterpenes from Chloranthus japonicus

Chemical investigation of the roots of Chloranthus japonicus Sieb . has resulted in the isolation and characterization of four new eudesmane‐type sesquiterpenes including two new sesquiterpene cinnamates, along with one new and two known sesquiterpene dimers. Their structures were established by spectroscopic means and by comparison with the respective literature values.     

Two New Eremophilane Sesquiterpenes from Cacalia ainsliaeflora

The root of C. ainsliaeflora has been used for curing pellagra, rheumatismal edema and insecticide1. In this paper, we report the structure elucidation of two new eremophilane sesquiterpenes (1, 2) from the roots of C. ainsliaeflora. Compound 1, colorless gum, [(]: -50 (c 0.50, CHCl3). HRESI-MS showed [M+H]+ at m/z 377.19528 (calcd for C21H29O6 377.19587), corresponding to a molecular formula C21H28O6. Its IR bands (1655, 1717, 1750cm-1) and UV absorptions (221 nm) displayed the typi…     

Pyrrolizidine Alkaloids and Bisabolane Sesquiterpenes from the Roots of Ligularia cymbulifera

The new pyrrolizidine alkaloid glycoside 1 , and the three new highly oxygenated bisabolane sesquiterpenes 4 – 6 , together with the two known pyrrolizidine alkaloids 2 and 3 , were isolated from the roots of Ligularia cymbulifera (W. W. Smith ) Hand .‐Mazz . Their structures were established on the basis of spectroscopic analysis, especially 1D‐ and 2D‐NMR data. The cytotoxic activities of compounds 1, 2 , and 4 – 6 were evaluated against hepatoma (BEL‐7402), human leukemia (HL‐60), human ovarian carcinoma (HO‐8910), and nasopharyngeal carcinoma (KB) cell lines (Tables 1–3). Compound 6 s howed weak cell‐growth inhibition of BEL‐7402 cell.     

New Sesquiterpenes from Cacalia ainsliaeflora

Two new eremophilane sesquiterpenes, 3β-angeloyloxy-8-oxo-eremophil-6(7)-en-12-oic acid 1 and 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en-12-oic acid 2, and a novelnor-eremophilane derivative, 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en 3 were isolated from the roots of Cacalia ainsliaeflora. Their structures were elucidated by spectroscopic methods, including 2D NMR.     

Three New Bisabolane Sesquiterpenes from Ligularia songarica

Three new bisabolane sesquiterpenes, songaricalarins F–H ( 1 – 3 , resp.), and five known analogs, 4 – 8 , were isolated from roots and rhizomes of Ligularia songarica. The structures were elucidated by spectroscopic methods, including 2D‐NMR techniques. The isolated compounds were also evaluated for their cytotoxic activities, against human lung carcinoma (A‐549) and human breast adenocarcinoma (MCF‐7) cell lines, and three compounds were found to show moderate cytotoxicities.     

Three New Sesquiterpenes from Laggera pterodonta

A new eremophilane sesquiterpene, (2β)‐2‐deoxo‐2‐methoxytessaric acid ( 1 ), and two new eudesmane sesquiterpenes, (3β,10α)‐3‐methoxyleudesma‐4,11(13)‐dien‐12‐oic acid ( 2 ) and (3α,4β,8α)‐4‐(acetyloxy)‐3‐(2,3‐dihydroxy)‐2‐methyl‐1‐oxobutoxy‐8‐hydroxyeudesm‐7(11)‐eno‐12,8‐lactone ( 3 ), along with the ten known compounds 4 – 13 were isolated from the aerial parts of Laggera pterodonta. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR data.     

Two New Sesquiterpenes from Ligularia lankongensis

In continuation of a systematic investigation into the chemotaxonomic and bioactive components of pyrrolizidine alkaloids and sesquiterpenoids of Ligularia plants, two new, highly oxygenated, rare bisabolene sesquiterpenes, compounds 1 and 2 , were isolated from the roots of Ligularia lankongensis. Their structures and relative configurations were elucidated by means of 1D‐ and 2D‐NMR as well as MS analyses.     

Efficient Total Synthesis of Racemic Bisabolane Sesquiterpenes Curcuphenol and Xanthorrhizol Starting from Substituted Acetophenones

A total synthesis of natural bisabolane sesquiterpenes curcuphenol ( 1 ) and xanthorrhizol ( 2 ) was developed by using the substituted acetophenones 4 and 5 , respectively, as starting materials. The acetyl group of the latter was activated through ethoxycarbonylation to carry out the prenylation, which was performed successfully to give their respective precursors 11a and 11b , and 21 that were converted into the corresponding natural sesquiterpenes 1 and 2 , respectively, over four steps and in high overall yields.     

New Sesquiterpenes from Ligulariopsis Shichuana

A thorough investigation of Ligulariopsis shichuana afforded five new sesquiterpenes, including 1β,10β‐epoxy‐3α‐angeloyloxy‐9β‐acetoxy‐8α,11β‐dihydroxybakkenolide ( 1 ), 1β,7‐dihydroxy‐3β‐acetoxy‐noreremophil‐6(7),9(10)‐dien‐8‐one ( 2 ), 8α‐hydroxy‐3‐oxoeremophil‐1(2),7(11),9(10)‐trien‐8β(12)‐olide ( 3 ), 1β,10β‐dihydroxy‐3β‐acetoxyeremophil‐7(11),8(9)‐dien‐8(12)‐olide ( 4 ) and 1β,10β‐epoxy‐8,12‐dihydroxy‐3β‐acetoxy‐9β‐angeloyloxyeremophil‐7(11)‐en‐8,12‐disemiketal ( 5 ). Their structures were established by spectroscopic methods and 2D NMR techniques. In addition, bakkenolide ( 1 ) and eremophilenolides ( 5 ) showed antibacterial and cytotoxic activities.