Diplophyllum species

A simple drimane-type sesquiterpene alcohol, (—)-drimenol (297) which is the direct cyclization product of farnesol, has been isolated from Bazzania trilobata (149). Albicanol (298), a double bond isomer of (297), was isolated from Diplophyllum species its structure and stereochemistry were established on the basis of the LIS-values in H-NMR spectrum, the formation of the same drimanol, on hydrogenation of (297) and (298) and the observation that acid-catalyzed isomerization of (297) and (298) gave the same mixture of products (281). 

The eudesmanolides (343, 348, 353, 359, 360) in Table I have been detected by GC-MS. Chiloscyphus and Diplophyllum species contain neither C-6/C-7 eudesmanolides nor eremophilanolides, although Frullania species elaborate both lactone series. 

X-Ray crystallographic analysis has led to a revised cycloaromadendrane structure for (-)-myliol (619), a metabolite of the liverwort Mylia taylorii ° cf. Vol. 4, p. 135 Vol. 6, p. 90). More recent investigations have resulted in the isolation of an isomeric compound, (—)-dihydromylione A (620) from the same source. Independent studies have also revealed the widespread occurrence of a closely related hydrocarbon, anastreptene (177), in the essential oils of various liverworts Anastrepta oveadensis, Diplophyllum albicans, Barbilophozia species) cf. p. 

Albicanal (288) and (-)-drimenol (289) are simple drimane sesquiterpenoids isolated from the liverwort, Diplophyllum serrulatum, and many other liverworts and higher plants. The latter compound was incubated with M. plumbeus and R. arrhizus. The former microorganism converted 289 to 6,7a-epojQ - (290), 3p-hydroxy- (291), and 6a-drimenol (292) in the yields of 2%, 7%, and 50%, respectively. On the other hand, the latter species produced only 3p hydroxy derivative (291) in 60% yield (Aranda et al., 1992) (Figure 20.90). 

Liver mosses the chemistry of liver mosses has been studied intensively during the past years. Among the volatile components, a range of terpenoids, often with a unique structure, have been reported [12]. (—)-Bicyclogermacrene has been identified as a constituent of various liverworts such as Plagiochila asplenioides, Diplophyllum albicans, wA Mylia species [13]. 

Cw-a-bisabolene (241) and its trans-xsomQX (242) are present in Scapania species (2). ( —)-P-Bisabolene (234) has been isolated from Diplophyllum albicans 281). 

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