Sesquiterpenes of nine european liverworts from the genera, Anastrepta,bazzania, jungermannia,lepidozia and Scapania

The essential oils of fourteen liverwort specimens from nine species of the Jungermanniales have been examined as to their sesquiterpenes. The barbatenes prove to be present in detectable amounts in all but one species. Bazzanene is frequently found with the barbatenes and new chemical evidence does not support the previously assigned structure but is consistent with a structure diastereomeric to trichodiene. This is consistent with a biogenetic rationale for the barbatene skeleton. Anasterptene, a novel crystalline tetracyclic hydrocarbon, has been found in numerous oils, and chemical degradation established a common skeleton with myliol. The samples of genus Scapania elaborate sesquiterpenes of the enantiomeric humulene-longifolene sequence. New members of this group found are (?)-β-longipinene, (?)-longipipanol, and (+)-γ-himachalene. The related germacrene series is represented by a cadinene, (?)-α-ylangene, and (?)-sativene. A series of cis-fused selinenes have also been found, which are more closely allied to the germacrene-sativene group than to typical trans-fused selinenes. One of these selinenes is shown to be the same as the material previously designated as sibirene. Scapania undulata also elaborates (+)-α- and β-chamigrene, and a number of novel hydrocarbons of still unknown structure.     

Sesquiterpenoids of Riccardia and Pallavicinia species

Riccardia species (Metzgeriales) contain various types of sesquiterpenes. R. jackii produces ent-selinane-, ent-aromadendrane-and ent-bicyclogermacrane-type sesquiterpenes together with (R)-cuparene and α-barbatene. Aneura pinguis (= Riccardia pinguis) is chemically quite different from R. multifida and R. jackii. The former produces a large amount of pinguisone. R. multifida contains 6-(3-methyl-2-butenyl)-indole and (+)-β-elemene as the major components. Pallavicinia longispina (Dilaenaceae; Metzgeriales) produces mainly spathulenol. The chiral properties of the sesquiterpenes isolated from R. jackii are quite similar to those of red algae, Laurencia species.     

Sesquiterpenes from Japanese liverworts

Five Japanese liverworts (Bazzania sp.) were examined for sesquiterpenes. B. japonica and B. pompeana contained two new drimane-type sesquiterpene esters, albicanyl 3,4-dihydroxycinnamate and albicanyl 2,4dihydroxycinnamate. Tridensenone, a new aromadendrane-type sesquiterpene ketone was isolated from B. tridens. The stereostructures of these new sesquiterpenes were elucidated mainly by spectrometry. Barbatane-, bazzanane- and cuparane-type sesquiterpenes were found in all of the five species investigated. These sesquiterpenes, along with the new drimane- and aromadendrane-type sesquiterpenes are useful chemosystematic markers.     

Sesquiterpene lactones of Conocephalum conicum

Investigation of the plant growth inhibitory activity of the extract of the liverwort, Conocephalum conicum afforded five sesquiterpene lactones, tulipinolide, zaluzanin C, zaluzanin D, 8α-acetoxyzaluzanin C and 8α-acetoxy-zaluzanin D. The latter two compounds are reported for the first time. Tulipinolide is responsible for the characteristic pungency of the female gametophyte of C. conicum. The guaianolides showed inhibitory activity toward the germination and growth of roots of rice in the husk. The male gametophyte of C. conicum indicated no pungency, showing the lack of tulipinolide.     

Flavonoid variation in the liverwort Conocephalum conicum: Evidence for geographic races

The flavonoids of 2 samples of Conocephalum conicum gametophyte tissue have been studied, one from U.S.A. and the other from Germany. Common to both samples were vicenin-2, lucenin-2, the 7-O-glucuronides of apigenin, chrysoeriol and luteolin and the previously unknown 7-O-glucuronide 4′-O-rhamnosides of apigenin, chrysoeriol and luteolin. Additionally the German sample contained the 7,4′-di-O-glucuronides of apigenin and luteolin and a new compound, apigenin 7-O-diglucuronide 4′-O-glucuronide. The North American sample contained, additionally, luteolin 7,3′-di-O-glucuronide, luteolin 7-O-glucuronide 3′,4′-di-O-rhamnoside (a new triglycoside) and 2 further derivatives of luteolin 7-O-glucuronide. Evidence is presented for the existence of geographic faces of C. conicum and for the qualitative invariability of the flavonoid patterns with changing season or environment.     

Pungent sesquiterpene lactones of the european liverworts Chiloscyphus polyanthus and Diplophyllum albicans

The characteristic pungency of the European liverwort, Chiloscyphus polyanthus, is due to a mixture of four sesquiterpene lactones, two new structures ent-5β-hydroxydiplophyllin and ent-3-oxodiplophyllin, and the previously known diplophyllin and diplophyllolide. A new dihydrodiplophyllin, together with the pungent diplophyllolide and diplophyllin, has been isolated from Diplophyllum albicans. Ent-dihydrodiplophyllolides derived from the above pungent diplophyllolides produce intense numbness of the tongue. All pungent sesquiterpene lactones showed inhibitory activity towards the germination and root elongation of rice husks.     

Sesquiterpenes of six Porella species (hepaticae)

The distribution in six Porella species of drimane-, aromadendrane- and pinguisane-type sesquiterpenes and norsesquiterpenes is described. The sharp pungent substance of P. gracillissima, P. fauriei and P. macroloba is (+)-tadeonal.     

Lunularic acid and related compounds in liverworts,algae and Hydrangea

Lunularic acid and lunularin were detected in 76 species of hepatics, but not in any of the Anthrocerotales or Algae examined. Lunularic acid, lunularin, 3,4′-dihydroxystilbene and a glycoside of lunularic acid were also identified in extracts of Hydrangea macrophylla roots, together with hydrangenol, hydrangeic acid and their glucosides.     

Chirality of terpenoids isolated from the liverwort Conocephalum conicum

Reinvestigation of a Japanese sample of the thalloid liverwort Conocephalum conicum afforded (+)-bornyl ferulate and bornyl 2 - methoxy - 4 - hydroxycinnamate together with (?) - limonene, (?) - β - sabinene, (+) - bicycloelemene, (+) - β - elemene, (?) - bicyclogermacrene, lunularin, and the two compounds, 1 - octen - 3 - ol and 1 - octen - 3 - yl acetate, responsible for the mushroom-like odour of the crushed thallus. The chirality of the compounds isolated is discussed.     

Aromatic esters and terpenoids of the liverworts in the genera Trichocolea, Neotrichocolea and Trichocoleopsis

Three liverworts, Trichocolea tomentella, Neotrichocolea bissethii and Trichocoleopsis sacculata belonging to Jungermanniales were chemically investigated. Isoprenyl benzoates are the important chemical markers of Trichocolea tomentella. Neotrichocolea bissethii elaborates sesquiterpenes as the major components. The sacculatane-type diterpenes and pinguisane-type sesquiterpenes are the significant chemosystematic markers of Trichocoleopsis sacculata. These three species are chemically quite different. Trichocoleopsis sacculata is chemically rather close to Porella species. The present chemical results support the recent morphological classification of the above three species proposed by Schuster. Some species of Jungermanniales are chemically identical to those of Metzgeriales and these results also support the phylogenetic classification in which the two orders have been united within the subclass Jungermanniae.     

Distribution pattern of sterols in liverworts belonging to the jungermanniineae

The sterol fractions of eight leafy liverworts were analyzed by GLC and GC-MS. Five 3β-sterols, cholest-5-en-3β-ol, 24-methylcholest-5,22-dien-3β-ol, 24-methylcholest-5-en-3p-ol, 24-ethylcholest-5,22-dien-3β-ol and 24-ethylcholest-5-en-3β-ol, were detected in all samples but there were differences in the relative amounts present.     

The taxonomic position of Sphaerocarpos and Riella as indicated by their flavonoid chemistry

The major flavonoid glycosides of Sphaerocarpos texanus are luteolin 7-O-glucuronide and 7,4′-di-O-glucuronide. Riella americana and R. affinis both contain apigenin, chrysoeriol and luteolin 7-O-glucuronides but R. americana additionally contains luteolin 3′-O-glucuronide. This finding supports the inclusion of Sphaerocarpaceae and Riellaceae in the order Marchantiales rather than their separation into another order.     

Plagiochilines C,D, E and F,four novel secoaromadendrane-type sesquiterpene hemiacetals from Plagiochila asplenioides and Plagiochila semidecurrens

Four novel secoaromadendrane-type sesquiterpene hemiacetals, plagiochilines C, D, E and F, together with the previously known (?)-bicyclogermacrene, have been isolated from the liverwort, Plagiochila asplenioides and their structures have been spectroscopically elucidated. From Plagiochila semidecurrens plagiochilines A and C have been obtained along with (?)-bicyclogermacrene and its related sesquiterpene hydrocarbons.     

Lunularic acid decarboxylase from the liverwort Conocephalum conicum

Some properties of a preparation of an enzyme, lunularic acid decarboxylase, from the liverwort Conocephalum conicum are described. The enzyme is normally bound and could be solubilized with Triton X-100; at least some of the bound decarboxylase activity appears to be associated with chloroplasts. For lunularic acid the enzyme has K_m 8.7 × 10^?5 M (pH 7.8 and 30°). Some substrate analogues have been tested but no other substrate was found. Pinosylvic acid is a competitive inhibitor for the enzyme, K_i 1.2 × 10^?4 M (pH 7.8 and 30°). No product inhibition was observed. Lunularic acid decarboxylase activity has also been observed with a cell-free system from Lunularia cruciata.     

Biosynthesis of sesquiterpenes in Hymenaea inferred from their quantitative co-occurrence

Leaf pocket resins of 11 species of the tropical arborescent genus Hymenaea are virtually identical qualitatively, but of widely varying quantitative proportions. Within this large range of variability, several strong positive quantitative correlations between resin constituents were found, especially between caryophyllene and β-humulene and between γ-muurolene and δ-cadinene. These data lead to clarification of sesquiterpene biosynthetic routes in Hymenaea. In addition, quantitative relationships found among caryophyllene, α- and β-selinene, γ-muurolene and δ-cadinene are explained only with difficulty by long accepted biosynthetic pathways, and the intermediacy of germacrenes is suggested.     

Isoscutellarein and hypolaetin 8-glucuronides from the liverwort Marchantia berteroana

The major flavonoid of Marchantia berteroana is hypolaetin 8-O-β-d-glucuronide. This is accompanied by apigenin and luteolin, isoscutellarein (8-hydroxyapigenin) 8-O-β-d-glucuronide, the 7-O-β-d-glucuronide and -galacturonide of apigenin and luteolin, luteolin 3′-O-β-d-glucuronide and -galacturonide, luteolin 7,3′-di-O-β-d-glucuronide and -galacturonide, luteolin 3′,4′-di-O-β-d-glucuronide and -galacturonide, luteolin 7,4′-di-O-β-d-glucuronide, and hypolaetin 8,4′-di-O-β-d-glucuronide. The isoscutellarein and hypolaetin glucuronides, and the galacturonide flavones are all new natural products.     

Sesquiterpenes from Perezia carpholepis

The previously unknown curcuquinol monoisovalerate and the known sesquiterpenes cyperene, cyperone, parvifoline, perezone, and α- and β-pipitzol were found in the roots of Perezia carpholepis. The structure of the new sesquiterpene was deduced from spectral data and by transformation into curcuquinone. Parvifoline and its derived acetate, previously thought to be oily materials, were characterized as crystalline compounds.     

Sesquiterpenes from Artemisia princeps

Copaene, cyperene, caryophyllene, β-farnesene, α-himachalene, γ-humulene and farnesyl acetate were isolated from the root of Artemisia princeps. As a result of isomerization studies on γ-humulene, the main constituent, a preferred conformation was proposed.     

Sesquiterpenes from Cacalia hastata

From the roots of Cacalia hastata L. subsp. orientalis Kitamura 5 sesquiterpenes were isolated; fukinone (I), dehydrofukinone (II), bakkenolide A (III), cacalohastine (IV) and dehydrocacalohastine (V).