BackgroundThe Arc of Fire across southern Amazonia seasonally attracts worldwide attention as forests are cut and burned for agricultural expansion. These forests contain numerous wild relatives of native South American crops, such as peach palm.Methodology/Principal FindingsOur prospecting expeditions examined critical areas for wild peach palm in the Arc of Fire in Mato Grosso, Pará, Maranhão and Tocantins, as well as areas not previously examined in Amazonas and Amapá states. Recent digitization of the RADAM Brasil project permitted comparison among RADAM's parataxonomists' observations, previous botanical collections and our prospecting. Mapping on soils and vegetation types enabled us to hypothesize a set of ecological preferences. Wild peach palm is best adapted to Ultisols (Acrisols) in open forests across the Arc of Fire and westward into the more humid western Amazonia. Populations are generally small (fewer than 10 plants) on slopes above watercourses. In northern Mato Grosso and southern Pará soybean fields and pastures now occupy numerous areas where RADAM identified wild peach palm. The controversial BR-163 Highway is already eroding wild peach palm as deforestation expands.Conclusions/SignificanceMany of these populations are now isolated by increasing forest fragmentation, which will lead to decreased reproduction via inbreeding depression and eventual extinction even without complete deforestation. Federal conservation areas are less numerous in the Arc of Fire than in other parts of Brazilian Amazonia, although there are indigenous lands; these conservation areas contain viable populations of wild peach palm and require better protection than they are currently receiving. Ex situ conservation of these populations is not viable given the relative lack of importance of domesticated peach palm and the difficulty of maintaining even economically interesting genetic resources.

Os óleos essenciais das folhas de Cordia leucomalloides e Cordia curassavica foram obtidos por hidrodestilação e suas composições químicas determinadas por uma combinação de CG-EM e CG-DIC. Como resultado, vinte e três componentes foram identificados em ambos os óleos, representando 98,6 e 91,2% da composição volátil. O óleo essencial de C. leucomalloides foi caracterizado por uma alta percentagem de sesquiterpenos (90,6%), sendo δ-cadineno (17,4%), (E)-cariofileno (15,7%), biciclogermacreno (12,5%) e germacreno D (11,2%) os majoritários. Por outro lado, o óleo de C. curassavica mostrou proporções similares de monoterpenos (47,3%) e sesquitepenos (43,9%), entre os quais α-pineno (20,5%), β-pineno (13,1%), (E)-cariofileno (12,4%) e biciclogermacreno (13,8%) foram os compostos predominantes. O potencial larvicida dos dois óleos foi avaliado contra larvas no terceiro estágio do mosquito Aedes aegypti. Os resultados mostraram que ambos os óleos apresentaram atividade biológica significativa, particularmente o óleo essencial de C. leucomalloides, o qual foi capaz de matar 98,7% das larvas numa concentração de 100 ppm.The essential oils obtained from the leaves of Cordia leucomalloides and Cordia curassavica were obtained by hydrodistillation and their chemical compositions determined by a combination of GC-MS and GC-FID. Twenty-three components were tentatively identified in both oils representing 98.6 and 91.2% of the volatile content. The oil of C. leucomalloides was characterized by a large percentage of sesquiterpenes (90.6%), being δ-cadinene (17.4%), (E)-caryophyllene (15.7%), bicyclogermacrene (12.5%) and germacrene D (11.2%) the major ones. On the other hand, the oil of C. curassavica showed similar proportions of monoterpenes (47.3%) and sesquiterpenes (43.9%) among which α-pinene (20.5%), β-pinene (13.1%), (E)-caryophyllene (12.4%) and bicyclogermacrene (13.8%) were the predominant compounds. The larvicidal potential of the two oils were evaluated against the third-instar of Aedes aegypti larvae. The results showed that both oils exhibited significant activity, particularly the oil of C. leucomalloides which was able to kill 98.7% of the larvae in the concentration of 100 ppm. Keywords:Cordia leucomalloides, Cordia curassavica, essential oil, larvicidal activity, terpenoids IntroductionThe pantropical genus Cordia, represented by shrubs and trees, is one of the major and most important genus of the family Boraginaceae. 1 Some of its species yield excellent wood naturally resistent to attack of several organisms, 2,3 while others are widely used in traditional medicine in several parts of the world. 4 13 and C. globosa (Jacq.) H.B.K. 14 have been described. The two later were recently subject of our studies, including their essential oils. A literature survey revealed that the oil of C. leucomalloides has not been reported but C. curassavica has been the subject of several studies, probably due its etnobotanical value. 1,5,6,15 C. curassavica is a medicinal plant with anti-inflammatory and antimicrobial prop...

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