José Cuatrecasas

Tricyclic sesquiterpenes and further diterpenes from Espeletiopsis species

Abstract The investigation of five Espeletiopsis and two Coespeletia species afforded, in addition to numerous known compounds, two new kaurene derivatives 19-acetoxy-ent-kaurene and 17-oxo-ent-kaur- 15-en-19-oic acid, as well as two new tricyclic sesquiterpenes, one being the previously reported oxidation product of copaborneol and the second one the 5-oxo derivative of silphiperfol-6-ene. The structures were elucidated by NMR studies and by chemical transformations. The chemotaxonomic situation is discussed briefly.

Neue diterpene aus der subtribus espeletiinae

The investigation of several species from the newly created subtribe Espeletiinae afforded in addition to known compounds seven new diterpenes and two norditerpenes. The structures were elucidated by intensive 1H-NMR studies. The chemotaxonomic situation is discussed briefly.

Studies on Andean Compositae-IV.

This is a continuation of my series of studies on Andean Compositae, published mainly as a preliminary to a general synopsis of the Senecioneae of the tropical Andean region and for a projected Flora of Colombia. It ineludes descriptions of new taxa, new combinations, and conlimeilts on Cacaliat, Paracalia, Chersodoma, Gynoxys, Senecio, and Baccharis. The material studied ineludes not only the South American collections of the U. S. National Herbarium, but also Peruvian plants recently collected by H. Ellenberg and by Rauh-Hirsch, respectively lent for identification by the Botanical Museum and Herbarium of Utrecht (U) and the New York Botanical Garden (NY). The work upon which this paper is based has been sponsored by the National Scieliee Foundation. The preceding article of this series was published in Brittonia 8: 179-193 (1956).

Neue sesquiterpene und norditerpene aus vertretern der gattung Libanothamnus

Abstract The aerial parts of L. granatesianus afforded in addition to known compounds two nor- ent -kaurenes, while those of L. occultus yielded in addition to several diterpenes, two new dialdehydes derived from silinene. The chemotaxonomic situation is discussed briefly.

New species of Compositae from Ecuador, collected by W. H. Camp

Gynoxys azuayensis Cuatr., sp. nov. Arbuscula ad 8 met. alta ramulis terminalibus plus minusve flexuosis angulosostriatis ferrugineo-tomentulosis. Folia opposita petiolata coriacea. Petiolus 2-3 cm. longus stria,us ferrugineotomentosus supra sulcatus. Lamina elliptico-oblonga vel lanceolato-oblonga, basi cordata vel subcordata apicem versus angustata apice obtusa vel acutiuscula, margine integra, 7-17 cm. longa, 3.5-6.5 cm. lata; supra juvenilis stellatopilosa denique nervo medio conspicuo pilosiusculo excepto glabra, nervis secundariis pallidis visibilibus reticulo nervulorum paulo conspicuo; sub,us ferrugineo-tomentulosa costa crassa prominenti striata nervis secundariis 9-10 utroque latere paulo ascendentibus prominentibus nervulis laxe reticulatis plus minusve conspicuis. InfIorescentiae terminales cymoso-paniculatae basl follosae folia non vel parum excedentes, axi ramulisque striolatis rufo=tomentosls plus minusve flex.uosis bracteolis linearibus brevibus munitis. Pedicelli teneres 4-20 mm. longi tomentelli sparsls bracteolis linearibus minutis ad apicem vix calyculum formantibus. Capitula radiata. Involucrum subconicum 8 bracteis submembranaceis oblongis subacutis 4.5 mm. longis, exterioribus 1 mm. la t i s extus tomentellis, interioribus 2-2.2 ram. latis margine late scariosis dorso ,omen,ellis. Flores marginales feminei ligulati circa 5, corolla 10.5=11 mm. longa glabra tuhulo 3.5 mm. longo lamina tridentata 2 mm. lata. Flores disci hermaphroditi tubulnsi 1011, corolla 7 mm. loaga glabra tubulo 3 ram. 1ongo dentibus oblongis 2 mm. longis. Antherae 2 mm. longae basi apiculatae. Stigmata conica. Ovarium glabrum. Pappus 6.5 mm. longus pills apice incrassatis. Azuay: The eastern Cordillera 4-6 km. north of the village of Sevilla de Oro, 9000-10000 ft. elev. Trees to 6 m. Lvs. coriaceous deep green above, the pubescence markedly reddish, especially so in the young growth. Bracts deep green tipped with reddish brown. Ray and disc fls. iyellow. W. H. Camp E.4724-B (F, holotype). G. azuayensis is closely related to G. cbagalensis Hieron., from which it differs by its long pedicels, much smaller heads, the somewhat lanceolate leaves, and by its shorter, less hirsute, tomentum.