The semi-synthetic kaurane ent-16 alpha-methoxykauran-19-oic acid induces vascular relaxation and hypotension in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new ent-kaurane diterpene from stems of Alibertia macrophylla K. Schum. (Rubiaceae)

Phytochemical investigations of the stems of a specimen of Alibertia macrophylla led to the isolation and characterization of the new diterpene ent-kaurane-2β,3α,16α-triol (1), along with triterpenes 2-8, iridoids 9-12, and phenolic acids 13-15. The structure of 1 was established based on spectroscopic studies (1H- and 13C-NMR, IR, and HR-ESI-MS). This is the first report of the isolation of a diterpene from the Alibertia genus in Rubiaceae. © 2007 Verlag Helvetica Chimica Acta AG.

Diterpene esters of aristolochic acids from Aristolochia pubescens

From the acetone and ethanol extracts of the tubercula of Aristolochia pubescens, two diterpene esters of aristolochic acids were isolated, together with 23 known compounds. The structures of the compounds were determined on the basis of spectroscopic analysis. (C) 2003 Elsevier Ltd. All rights reserved.

A general survey and some taxonomic implications of diterpenes in the Asteraceae

This paper provides a general survey of the occurrence of diterpenes in the Asteraceae. Data on 4351 botanical occurrences were obtained from the literature. These were grouped by skeleton for each genus. Then, the genera were grouped by subtribes, which, in turn, were gathered in tribes, followed by subfamilies. In spite of the low number of species containing diterpenes, it was possible to describe some structural features of these compounds, i.e. The skeletal types in various taxa and the positions in some skeletons that are always oxidized or never undergo oxidation in some genera. Thus, it was verified that: in the subfamily Cichorioideae, only a few of the studied species possess diterpenes, wherein kaurane is the most frequent diterpene skeleton. In the Asteroideae, the presence of diterpenes is much greater than that in the Cichorioideae and Carduoideae. At tribal taxonomic level, for example, the Astereae produce labdanes and clerodanes; Heliantheae and Eupatorieae produce kauranes and labdanes, respectively; and Calenduleae produce pimaranes. Some taxonomic implications are presented. (c) 2005 the Linnean Society of London.

Insecticidal activity of chemical constituents from Aristolochia pubescens against Anticarsia gemmatalis larvae

Acetone and ethanol extracts of the tubercula and several compounds isolated from Aristolochia pubescens (Willd) were bioassayed on velvebean caterpillars, Anticarsia gemmatalis (Hubner), for evaluation of the insecticidal activities. of the extracts subjected to bioassay, the acetone extract showed the highest activity. (-)-Cubebin did not show activity against soybean caterpillars, whereas aristolochic acid and ent-kaur-15-en-17-ol increased the larval period. These compounds, and (+)-eudesmin and (+)-sesamin, reduced the viability of this period, giving rise to malformed adults. These extracts and compounds are therefore potential botanical insecticide agents for the control of velvetbean caterpillars in soybean crops. (C) 2003 Society of Chemical Industry.

Diterpenic adducts from Xylopia species

Xylopia emarginata and X. amazonica contain diterpene adducts probably originating from Diels-Aider reaction between labdane and kaurane derivatives. This type of substance seems to be characteristic of the genus Xylopia. © 1991.

Chrysobalanaceae: Secondary metabolites, ethnopharmacology and pharmacological potential

Many Chrysobalanaceae species, in special Licania and Parinari, are widely used in folk medicine to treat several diseases. This review describes some aspects of their ethnopharmacology potential, biological activities and the secondary metabolites reported so far for Chrysobalanaceae. The chemical constituents of this family include triterpenoids, diterpenoids, steroids and phenylpropanoids like flavonoids as well as chromones derivatives. © 2012 Springer Science+Business Media Dordrecht.

Terpenes from Aristolochia triangularis

Phytochemical examination of Aristolochia triangularis led to the isolation of allantoin, nerolidol, sitosterol, dibenzylbutyrolactone type lignans and ent-kaurane type diterpenes. This is the first report on the isolation of ent-kaurane from a natural source. © 1990.