Genera, monotypic

Pterolactam (48) was isolated from bracken (Pteridium aquilinum Kuhn), a fern belonging to a monotypic genus (86). Its IR spectrum strongly resembles the IR spectrum of 2-pyrrolidone the structure of 48 was established by 1H-NMR spectroscopy. It is interesting to note that 48 possesses a weak but definitive optical rotation ([a]D —2.0°). 

Peripentadenia is a monotypic genus of the family Elaeocarpaceae represented by Peripentadenia mearsii (C. T. White) L. S. Smith, a tree growing in rain forests of northern Queensland. Besides unidentified minor alkaloids, the species yields one major alkaloid, peripentadenine (49) (87). Its molecular formula, C22H34N203, was established by high-resolution mass spectroscopy the presence of phenol, ketone, secondary amide, and tertiary amine functionalities was deduced from examination of spectroscopic data. 

Taxane alkaloids have a very limited distribution within the plant kingdom, and occur only in two genera of the yew family (Taxus and Austrotaxus). The genus Austrotaxus is monotypic (A. spicata Compt), but contusion exists on the systematics of the genus Taxus, especially as regards the taxonomic status of certain Asian yews. Reference will be given here to the Krttssmann classification (Table 1) [28]. 

The seeds of this monotypic genus contain alkaloids to the extent of nearly 5% but, since nine alkaloids have been obtained from the base mixture, the available amount of any of them is not large, particularly since the plant is very rare. The leaves and bark provided only amorphous alkaloids. All of these alkaloids contain two nitrogens, only one of which is basic, and they all have one methoxyl. Most of them yield crystalline methiodides indicating that the basic nitrogen is tertiary. The presence of an imino-nitrogen could not be demonstrated so that the nature of the second nitrogen is still obscure. Table 2 records the names and some properties of the known alkaloids (134, 135). 

The genus Eremophila is one of three genera, together with Myoporum and Bontia, which constitute the small Myoporaceae family. This family is restricted largely to Australia except for species of Myoporum which extend north to China and Japan and to the islands of the Indian and Pacific Oceans, and Bontia, a monotypic genus found only in the West Indies. 

Humbertia, a monotypic Madagascan genus, is the sister to aU other members of the family... 

The results obtained by the molecular studies performed since 2002 and the subdivision of the core of the Hypopterygiaceae in two subclades found in the Bayesian inference analyses of our total evidence study confirm the polyphyly of Dendrohypopterygium s. lot. and support the recognition of Arbusculohypopterygium as a separate, monotypic genus (Stech et al., 2002) that accommodates Kruijer s (2002) second Dendrohypopterygium species (D. arbuscula). 

The largest of the four genera in the family is Entodon, with approximately 145 species globally, of which 11 occur in Africa. Erythrodontium has 16 species that are currently being revised, and four of these occur in Africa. There are two species in Mesonodon, one of which has an African and Asian distribution, and Pylaisiobryum is a monotypic African genus. 

There is another application of chemotaxonomy, actually chemotaxon-omy a rebours (in reverse). A chemist, pharmacologist, or biochemist can be guided by the botanist in searching for plants which produce compounds of special interest. The castor bean plant, Ricinus communis, produces a peculiar alkaloid, ricinine. Studies by Waller et al. (1966), Essery et al. (1962), and Jackanicz and Byerrum (1966), showed some of the pathway of its biosynthesis. The genus Ricinus is monotypic, represented by the single species R. communis. No other plant among the Euphorbiaceae is known to accumulate ricinine. In 1964, a new alkaloid, nudiflorine, was isolated by... 

A contemporary investigation of H. salicifolia and of H. myrtifolia Cham, et Schl. indicated that the alkaloid contents are such that these plants are not distinct specifically, a conclusion consonant with the view that Heimia is monotypic. The alkaloid content also indicates that the genus Heimia may be referred to Decodon. Both plants yielded lythrine, vertine, and lythridine, C23H2504N(0Me)2 (mp 219° [a]if —153°) hydrochloride (mp > 320°) 122). 

From this region, 202 taxa have been recorded. Of these, 57 taxa are restricted to this unit, including three monotypic genera Blanchetiodendron, Goniorrhachis and a new genus currently being described (L.P. Queiroz, G.P. Lewis, and M.F. Wojciechowski, in prep.). Data on the... 

Fisch, E., Vogel, S., and Lopes, A.V., Ametoglossion, a new monotypic genus of Scrophulariaceae-Scrophularioideae from Brazil, Feddes Repert., 110, 529, 1999. 

This is an extremely isolated genus, unrelated to the Lecanoraceae. It should be recognized as a separate monotypic family. 

The genus Frateuria was long thought to be monotypic. However, a second species was recently reported. 

Camptotheca acuminata Decne - This monotypic genus, native to W "mirihT alfld Ti srs yielded camptothecin(e), an alka-... 

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