Progress in the Chemistry of Organic Natural Products 113

In this book, chemical studies are described mainly from literature reports appearing since 2000, inclusive of investigations performed by the present authors, on the diversity in secondary metabolites of Ligularia growing in the Hengduan Mountains area of China, focusing on eremophilane sesquiterpenoids and other metabolites. More than 100 Ligularia species and their related genera in the plant family Senecioneae plants (Cremanthodium, Cacalia, Senecio, and others) grow in East Asia. For many years, researchers have studied the chemical constituents of these plants, and terpenoids, flavonoids, steroids, alkaloids, and aromatic compounds have been isolated. Among these, in particular, numerous sesquiterpenoids were reported. Within this book terpenoids and aromatic compounds (total 1049), both previously unknown and known, are presented. Finally, genetic studies and synthesis investigations are briefly reviewed. 

1                 Introduction

2                 Compounds

3                 Ligularia Species

3.1           Ligularia virgaurea (Maximowicz) Mattfeld ex Rehder & Kobuski

3.2           Ligularia dentata (A. Gray) H. Hara

3.3           Ligularia japonica (Thunberg) Lessing

3.4           Ligularia hookeri (C. B. Clarke) Handel-Mazzetti

3.5           Ligularia atroviolacea (Franchet) Handel-Mazetti

3.6           Ligularia kanaitzensis (Franchet) Handel-Mazzetti

3.7           Ligularia intermedia Nakai

3.8           Ligularia vellerea (Franchet) Handel-Mazzetti

3.9           Ligularia wilsoniana (Hemsley) Greenman

3.10       Ligularia melanothyrsa Handel-Mazzetti

3.11       Ligularia lapathifolia (Franchet) Handel-Mazzetti

3.12       Ligularia macrophylla (Ledebour) Candolle

3.13       Ligularia knorringiana Pojarkova (= L. thyrsoidea) and Ligularia narynensis (C. Winkler) O. Fedtschenko & B. Fedtschenko

3.14       Ligularia rumicifolia S. W. Liu

3.15       Ligularia songarica (Fischer) Y. Ling

3.16       Ligularia stenocephala (Maximowicz) Matsumura & Koidzumi

3.17       Ligularia alticola Voroschilov

3.18       Ligularia brassicoides Handel-Mazzetti

3.19       Ligularia caloxantha (Diels) Handel-Mazzetti

3.20       Ligularia przewalskii (Maximowicz) Diels

3.21       Ligularia sagitta (Maximowicz) Mattfield ex Rehder & Kobuski

3.22       Ligularia pleurocaulis (Franchet) Handel-Mazzetti

3.23       Ligularia fischeri (Ledebour) Turczaninow, Ligularia anoleuca Handel-Mazzetti, and Ligularia veitchiana (Hemsley) Greenman

3.24       Ligularia cyathiceps Handel-Mazzetti

3.25       Ligularia cymbulifera (W. W. Smith) Handel-Mazzetti

3.26       Ligularia dictyoneura (Franchet) Handel-Mazzetti

3.27       Ligularia duciformis (C. Winkler) Handel-Mazzetti, Ligularia konkalingensis Handel-Mazzetti, Ligularia nelumbifolia (Bureau & Franchet) Handel-Mazzetti, and Ligularia limprichtii (Diels) Handel-Mazzetti

3.28       Ligularia hodgsonii J. D. Hooker

3.29       Ligularia lamarum (Diels) C. C. Chang and Ligularia subspicata (Bureau & Franchet) Handel-Mazzetti

3.30       Ligularia lankongensis (Franchet) Handel-Mazzetti

3.31       Ligularia latihastata (W. W. Smith) Handel-Mazzetti and Ligularia villosa (Handel-Mazzetti) S. W. Liu

3.32       Ligularia longihastata Handel-Mazzetti

3.33       Ligularia oligonema Handel-Mazzetti

3.34       Ligularia tongolensis (Franchet) Handel-Mazzetti

3.35       Ligularia tsangchanensis (Franchet) Handel-Mazzetti

3.36       Ligularia yunnanensis (Franchet) C. C. Chang

3.37       Hybrid

3.38       Further Ligularia I: L. altaica Candolle, L. dolichobotrys Diels, L. dolichobotrys Diels, L. franchetiana (H. Léveillé) Handel-Mazzetti, L. persica Boissier, L. speciosa Fischer et Meyer, L. thyrsoidea (Ledebour) Candolle

3.39            Further Ligularia II: L. achyrotricha (Diels) Y. Ling, L. nanchuanica S. W. Liu, L. purdomii (Turrill) Chittenden, L. odontomanes Handel-Mazzetti, L. sibirica (Linnaeus) Cassini, L. thomsonii (C. B. Clarke) Pojarkova

3.40            Further Ligularia III: L. angusta (Nakai) Kitamura, L. calthifolia Maximowicz, L. fauriei (Franchet) Koidzumi, L. hiberniflorum (Makino) Kitamura, L. kangtingensis S. W. Liu, L. lingiana S. W. Liu, L. myriocephala Y. Ling ex S. W. Liu, L. platyglossa (Franchet) Handel-Mazzetti, L. schmidtii (Maximowicz) Makino

3.41            Further Ligularia IV: L. brachyphylla Handel- Mazzetti (= L. lathihastata), L. caltaefolia (Maximowicz) Diels, L. clivorum Maximowicz (= L. dentata), L. sachalinensis Nakai, L. tangutica (Maximowicz) Bergmans, L. trichocephala (Maximowicz) Matsumura et Koidzumi, L. vorobierii Worosh

4       Genetic Analyses

5        Synthesis Aspects

5.1         Synthesis of Ligularol = Petasalbin, Ligularone, and Related Compounds

5.2         Synthesis of Tetrahydroligularenolide Using Biogenetic Type Rearrangement

5.3         Synthesis of Furanoeremophilan-15,6-olide

5.4         Synthesis of Isopetasol

5.5         Synthesis of Eremophila-9,11-dien-8-one, Dehydrofukinone, and Furanoeremophilanes

5.6         Synthesis of Eremoligenol and Eremophilone

5.7         Synthesis of Eremophiladienes

5.8         Synthesis of Fukinone and Related Compounds

5.9         Synthesis of Eremohiladiene

5.10     Synthesis of 6-Hydroxyeuryopsin

5.11     Synthesis of 3b-Angeloyloxyfuranoeremophilane

5.12     Synthesis of Ligularone and Isoligularone

5.13     Synthesis of (–)-(R)-Ligularenolide and (–)-(R)-PF1092C

5.14     Synthesis of Nootkatone

5.15     Synthesis of Cacalol

5.16