A Diterpene fromMikania obtusataActive onTrypanosoma cruzi

Abstract

The diterpene ent-kaur-16-en-19-oic acid (1) was identified as the trypanocidal component of the ethanolic extract from Mikania obtusata D. C. (Asteraceae). This compound presents an IC50 of 0.5 mg/ml (1.66 mM) against the trypomastigote blood form of the Trypanosoma cruzi, the causative agent of Chagas' disease (American trypanosomiasis).

A simple synthesis of kaurenoic esters and other derivatives and evaluation of their antifungal activity

“…Methyl kaurenoate 2 has been prepared by diazotization of 1 in good yields by many research groups, 9,[19][20][21] but the harmful reaction conditions and the restrictions associated with the preparation of other diazoalkanes precluded its general use. On the other hand, synthesis of 3-hydroxypropyl kaurenoate 3 was achieved 22 by treatment of kaurenoic acid 1 with triphenylphosphine in carbon tetrachloride followed by addition of 1,3-propanediol to the unstable acyl chloride intermediate (Scheme 1).…”

“…6 Kaurenoic acid (1), along with several related kauranes, 7 exhibits a wide variety of biological activities such as antimicrobial, anti-inflammatory, anti-fertility, cytotoxic, and trypanocidal. [8][9][10][11][12][13][14][15][16] The relatively high natural abundance of kaurenoic acid (1) and the inexistence of a general method for the synthesis of alkyl kaurenoates by esterification of 1 provides further motivation to investigate its chemical modification 17 in order to obtain derivatives and test their pharmacological activity. 18 This paper describes a general synthesis of kaurenoic esters and derivatives as well as their antifungal activity, evaluated against a panel of human opportunistic pathogenic fungi including yeasts, hialohyphomycetes and dermatophytes.…”

Occurrence, Biological Activities and Synthesis of Kaurane Diterpenes and their Glycosides

“…Some of these kaurane biological effects have also been cited in recent literature [38,40,41,[48][49][50][51][52][53][54][55][56][57]. For this reason, Table 1 enumerates other biological activities described for kaurane diterpenes and related compounds reported since 1997.…”

“…In addition, a general survey and some taxonomic implications of the occurrence of kaurane and other classes of diterpenes in the Asteraceae family are discussed by Alvarenga and collaborators [39]. Kaurenoic acid (1), an ent-kaurane diterpene that possesses a wide spectrum of bioactivities such as antiinflammatory, antibacterial, antifungal and moluscical properties, among others [6], is not commercially available, but it is relatively abundant in some species belonging to the Wedelia [40], Mikania [41], Annona [42] and Xylopia [43] genera, which has motivated its quantification in these plant species [42][43][44][45][46][47], enabling the use of all of them as natural sources of this diterpene. Figure 3.…”

O gênero copaifera L.

“…O ácido caurenóico (D2) é descrito na literatura como tripanossomicida 243 , atividade conferida também a óleos de copaíba que não contêm este diterpeno 230 . Estudos realizados com ácido caurenóico isolado de Copaifera langsdorfii mostram também atividade relaxante do músculo liso, sobre contrações uterinas induzidas 244 .…”