Bioassay-guided fractionation of the bark extract of Annona foetida afforded a new antileishmanial pyrimidine-beta-carboline alkaloid, N-hydroxyannomontine (1), together with the previously reported annomontine (2), O-methylmoschatoline (3), and liriodenine (4). The structure of compound 1 was established on the basis of extensive 1D and 2D NMR and MS analyses. This is the third reported pyrimidine-beta-carboline-type alkaloid and is particularly important for Annona genus chemotaxonomy. In addition, all compounds exhibit in vitro antileishmanial activity against promastigote forms of Leishmania braziliensis. Compounds 2 and 4 showed better activity than compounds 1 and 3 against L. braziliensis. Compound 2 was not active against L. guyanensis.

O presente trabalho descreve o isolamento, a partir do caule de Annona amazonica, do ácido acantóico, um diterpeno do tipo pimaradieno que possui várias e importantes atividades biológicas descritas na literatura. Neste estudo foi verificado que este composto apresenta significante atividade tripanocida contra as formas epimastigotas de Trypanosoma cruzi. Também foi constatado que este diterpeno é o constituinte majoritário da planta, encontrado em cerca de 65% do extrato hexânico, demonstrando que A. amazonica é uma nova fonte natural renovável desta substância. Além do ácido acantóico, a investigação química resultou no isolamento dos alcalóides liriodenina e cassiticina, entre outros compostos, tais como terpenos, esteróides e ácidos graxos. Adicionalmente, é descrita a completa e inequívoca atribuição dos deslocamentos químicos de RMN de 1 H e 13 C da cassiticina.The present work reports the isolation of acanthoic acid, a promising pimaradiene-type diterpene with several important biological activities described in the literature, from the stems of Annona amazonica. We found that acanthoic acid has significant trypanocidal activity against the epimastigote forms of Trypanosoma cruzi. This diterpene is the major constituent of the plant, comprising at least 65% of the hexane extract, demonstrating that A. amazonica is a new renewable natural source for this compound. The chemical investigation also resulted in the isolation of the alkaloids liriodenine and cassythicine, and other compounds including terpenes, sterols, and fatty acids. Additionally, the complete and unequivocal 1 H and 13 C NMR chemical shift assignments for cassythicine are provided. Keywords: Annona amazonica, Annonaceae, acanthoic acid, cassythicine, trypanocidal activity IntroductionThe family Annonaceae, comprised of tropical and subtropical species with about 135 genera and more than 2500 species and widely distributed in South and Central America, Africa, Asia, and Australia, 1 is known for its edible fruits and the medicinal properties of several species. 2 In Brazil, there are 26 genera with about 260 species, including the genus Annona, which contains approximately 120 species. 3 Chemical investigations of species of Annonaceae have revealed their high chemical diversity in terms of secondary metabolites, such as alkaloids, acetogenins, terpenoids and lactones. These compounds have shown important biological activities, including antiparasitic, in particular against Leishmania sp., Plasmodium falciparum, and Trypanosoma cruzi. [4][5][6][7][8][9][10][11][12] Annona amazonica R.E. Fries is a tropical tree that grows up to 20-25 m tall and 35-60 cm in diameter, and is found from Panama to South America. In Brazil this species commonly occurs in the Amazon, mainly in the states of Amazonas and Pará. 13 To the best of our knowledge, only one previous phytochemical study has described the isolation and identification of cyanogenic constituents from this species. 14 Here we describe the isolation and structural identification of the chemica...

In this work, we present an image database for automatic bacilli detection in sputum smear microscopy. The database comprises two parts. The first one, called the autofocus database, contains 1200 images with resolution of 2816 × 2112 pixels. This database was obtained from 12 slides, with 10 fields per slide. Each stack is composed of 10 images, with the fifth image in focus. The second one, called the segmentation and classification database, contains 120 images with resolution of 2816×2112 pixels. This database was obtained from 12 slices, with 10 fields per slice. In both databases, the images were acquired from fields of slides stained with the standard Kinyoun method. In both databases, accordingly to the background content, the images were classified as belonging to high background content or low background content. In all 120 images of segmentation and classification database, the identified objects were enclosed within a geometric shape by a trained technician. A true bacillus was enclosed in a circle. An agglomerated bacillus was enclosed by a rectangle and a doubtful bacillus (the image focus or geometry does not allow a clear identification of the object) was enclosed by a polygon. These marked objects could be used as a gold standard to calculate the accuracy, sensitivity and specificity of bacilli recognition.

This paper presents a new method for segmentation of tuberculosis bacillus in conventional sputum smear microscopy. The method comprises three main steps. In the first step, a scalar selection are made for characteristics from the following color spaces: RGB, HSI, YCbCr and Lab. The features used for pixel classification in the segmentation step were the components and subtraction of components of these color spaces. In the second step, a feedforward neural network pixel classifier, using selected characteristics as inputs, is applied to segment pixels that belong to bacilli from the background. In third step geometric characteristics, especially the eccentricity, and a new proposed color characteristic, the color ratio, are used to noise filtering. The best sensitivity achieved in bacilli detection was 91.5%.