Topic
Trixis
About: Trixis is a research topic. Over the lifetime, 21 publications have been published within this topic receiving 479 citations.
Papers
TL;DR: Ethanol extracts of 83 plants species belonging to the Asteraceae (Compositae) family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis--Diptera: Culicidae and the extract from Tagetes minuta was the most active.
Abstract: Ethanol extracts of 83 plants species belonging to the Asteraceae (Compositae) family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis--Diptera: Culicidae). The extract from Tagetes minuta was the most active with a LC90 of 1.5 mg/l and LC50 of 1.0 mg/l. This plant has been the object of several studies by other groups and its active components have already been identified as thiophene derivatives, a class of compounds present in many Asteraceae species. The extract of Eclipta paniculata was also significantly active, with a LC90 of 17.2 mg/l and LC50 of 3.3 mg/l and no previous studies on its larvicidal activity or chemical composition could be found in the literature. Extracts of Achryrocline satureoides, Gnaphalium spicatum, Senecio brasiliensis, Trixis vauthieri, Tagetes patula and Vernonia ammophila were less active, killing more than 50% of the larvae only at the higher dose tested (100 mg/l).
204 citations
TL;DR: The results show that germination of seeds of a range of Asteraceae species varies with temperature and light regime; they provide an initial basis on which to test and interpret the effects of seasonal factors on germination and field establishment.
Abstract: Achenes of thirteen native Asteraceae species common to the natural grassland or weeds of the southern region of Brazil were tested for germination over a range of alternating temperatures ( 20/10; 25/15; 30/20 and 35/25°C), and under constant temperatures ( 20; 25 and 30°C) with light or not .Only fresh collected achenes (herein = seeds) were used. The optimum temperature for germination differed among the species, with Elephantopus mobillis; Eupatorium laevigatum; Mikania cordifolia; Senecio oxyphyllus; Trixis praestans germinating the most over all temperatures tested. Eclipta alba seeds germination was promoted at 30°C. Colder treatments promoted germination in Tagetes minuta , and in Senecio heterotrichius; S.selloi; Stenachaenium campestre; Symphyopappus casarettoi and Vernonia nudiflora germination was equivalent at 20 or 25°C. Light promoted germination for all species except in Stenachaenium campestre and Tagetes minuta, the latter being a negative photoblastic species. According to the mean time for germination, the species could be ranked in: fast -less than 5 days- (Baccharis trimera; Eclipta alba; Elephantopus mollis; Stenachaenium campestre and Vernonia nudiflora); intermediate: between 5 and 10 days- (Eupatorium laevigatum; Mikania cordifolia and Tagetes minuta) ; slow: more than 10 days-(Senecio heterotrichius; S.oxyphyllus; S.selloi; Symphyopappus casarettoi; Trixis praestans). The results show that germination of seeds of a range of Asteraceae species varies with temperature and light regime; they provide an initial basis on which to test and interpret the effects of seasonal factors on germination and field establishment. In addition, comments on the agar and sand substrates were made.
109 citations
TL;DR: The investigation of two further Trixis species afforded five new sesquiterpenes related to trixikingolide, six new germacrene derivatives and a sesiquiterpene derived from rotundene as discussed by the authors.
28 citations
TL;DR: In this article, two species of the South American genus Trixis afforded 12 new sesquiterpenes all with a new pentacyclic ring system, named trixikingolide.
Abstract: Zwei Vertreter der sudamerikanischen Gattung Trixi ergeben 12 neue Sesquiterpene, alle mit dem neuen pentacyclischen Ringsystem. das wir Trixikingolid genannt haben (3–8 und 19–24). Die Konstitutionen werden durch spektroskopische Methoden und chemische Umwandlungen, die zum Teil ungewohnlich sind, geklart. Das Kohlenstoffgerust ist das eines Isocedrens (1), das zuerst in mehreren Gattungen der Tribus Mutisieae gefunden wurde. Dieser Typ ist wahrscheinlich von chemotaxonomischer Bedeutung.
Naturally Occurring Terpene Derivatives, 156. On a New Group of Sesquiterpene Lactones from the Genus Trixis
Two species of the South American genus Trixis afforded 12 new sesquiterpenes all with a new pentacyclic ring system, named trixikingolide (3–8 and 10–24). The structures are elucidated by spectroscopic methods and chemical transformations which are in part unusual. The carbon skeleton is that of an isocedrene (1), first found in several other genera of the tribe Mutisieae. This type is probably of chemotaxonomical importance.
15 citations
TL;DR: The aerial parts of Trixis pallida afforded seven known trixanolides (18-24) together with 17 new trix ethanolides (1-17) and the absolute configuration of the trixane skeleton turned out to be enantiomeric to that reported using the Horeau method.
Abstract: The aerial parts of Trixis pallida afforded seven known trixanolides (18-24) together with 17 new trixanolides (1-17). Their structures were determined by 1D and 2D NMR techniques, while the absolute configuration of the trixane skeleton was determined using the Mosher method and turned out to be enantiomeric to that reported using the Horeau method. This result is further discussed from the biosynthetic point of view.
12 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2019 | 3 |
| 2011 | 1 |
| 2010 | 1 |
| 2006 | 1 |
| 2001 | 2 |