Bioassay-Guided Isolation of Fungistatic Compounds from Mimosa caesalpiniifolia Leaves.

A bioassay-guided phytochemical study of a Mimosa caesalpiniifolia leaf extract with antifungal activity permitted the identification of 28 compounds, including the new 6-(ß-boivinopyranosyl)apigenin (1), 8-(ß-oliopyranosyl)apigenin (2), (E)-6-(2-carboxyethenyl)apigenin (3), (E)-8-(2-carboxyethenyl)apigenin (4), and 7,5″-anhydro-6-(α-2,6-dideoxy-5-hydroxyarabinohexopyranosyl)apigenin (5). The structures of the new compounds were determined by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, and by mass spectrometry. Compound 3 showed promising activity and selectivity against Candida krusei (IC50 44 nM), which exhibits resistance to azoles. The association of the major components 3-ß-d-glucopyranosyloxysitosterol (8) and ethyl gallate (10) was synergistic against C. krusei, especially the IC values of compound 10, which were reduced by more than 100-fold.

Aspartic proteinases of Candida spp.: role in pathogenicity and antifungal resistance.

Fungal infections represent a serious health risk as they are particularly prevalent in immunocompromised individuals. Candida spp. pathogenicity depends on several factors and secreted aspartic proteinases (Sap) are considered one of the most critical factors as they are associated with adhesion, invasion and tissue damage. The production of proteinases is encoded by a family of 10 genes known as SAP, which are distributed differently among the species. The expression of these genes may be influenced by environmental conditions, which generally result in a higher fungal invasive potential. Non-pathogenic Candida spp. usually have fewer SAP genes, which are not necessarily expressed in the genome. Exposure to subinhibitory concentrations of antifungal agents promotes the development of resistant strains with an increased expression of SAP genes. In general, Candida spp. isolates that are resistant to antifungals show a higher secretion of Sap than the susceptible isolates. The relationship between Sap secretion and the susceptibility profile of the isolates is of great interest, although the role of SAPs in the development of resistance to antifungal agents remains still unclear. This review is the first one to address these issues.

Calcium salts of fatty acids with varying fatty acid profiles in diets of feedlot-finished Bos indicus bulls: impacts on intake, digestibility, performance, and carcass and meat characteristics.

We hypothesized that the inclusion of calcium salts of fatty acid (CSFA) into the diets and the fatty acid (FA) profile of the supplements would impact performance and meat characteristics of Bos indicus bulls. Hence, the objective was to evaluate the effects of CSFA profiles on intake, body weight (BW), carcass, and meat characteristics of feedlot-finished B indicus bulls. Fifty-three Nellore bulls [initial BW 315 ± 5.9 kg and 20 ± 2 mo] were used. At the beginning, 6 bulls were randomly chosen and slaughtered for determination of their BW composition, and the remaining 47 bulls were evaluated during a 140-d experimental period. The bulls were placed in individual pens, blocked according to initial BW and randomly allocated to 1 of the 3 following treatments: (1) control diet containing sugarcane bagasse, ground corn, citrus pulp, peanut meal, and mineral-vitamin mix (CON), (2) CON with the addition of 3.3% of CSFA from soybean oil (CSO), or (3) CON with the addition of a mixture of 3.3% of CSFA from palm, soybean, and cottonseed oils (CPSCO). Diets were offered ad libitum and formulated to be isonitrogenous. Bulls supplemented with CSFA had a greater (P < 0.01) final BW, dry matter intake, average daily gain (ADG), feed efficiency (FE), and FA intake vs. CON. Among carcass parameters, CSFA-supplemented bulls had greater (P < 0.01) carcass ether extract concentration vs. CON bulls. When the CSFA profile was evaluated (CSO vs. CPSCO), CPSCO bulls had a better (P ≤ 0.03) FE, carcass ADG, and hot carcass weight (HCW) vs. CSO bulls. The FA intakes differed among CSFA treatments, as the total saturated, palmitic, and oleic FA intakes were greater for CPSCO (P < 0.01), whereas lower intakes of total unsaturated and polyunsaturated FA (P < 0.01) were observed for CPSCO vs. CSO. Samples from the Longissimus muscle contained greater palmitoleic (P = 0.01) and reduced linoleic (P = 0.02) FA concentrations in CSFA-supplemented bulls vs. CON bulls. In agreement with the FA intakes, CPSCO-supplemented bulls had a greater (P ≤ 0.05) unsaturated FA concentration vs. CSO in Longissimus muscle. In summary, CSFA supplementation improved the performance of finishing B. indicus bulls vs. CON. Moreover, the inclusion of CSFA from palm, soybean, and cottonseed oil benefited the FE, carcass ADG, and HCW compared with the inclusion of CSFA from soybean oil, demonstrating the potential of specific FA for improving the performance and meat quality of B. indicus bulls.

Synthesis and Biological Evaluation of New Eugenol Mannich Bases as Promising Antifungal Agents.

New Mannich base-type eugenol derivatives were synthesized and evaluated for their anticandidal activity using a broth microdilution assay. Among the synthesized compounds, 4-allyl-2-methoxy-6-(morpholin-4-ylmethyl) phenyl benzoate (7) and 4-{5-allyl-2-[(4-chlorobenzoyl)oxy]-3-methoxybenzyl}morpholin-4-ium chloride (8) were found to be the most effective antifungal compounds with low IC50 values, some of them well below those of reference drug fluconazole. The most significant IC50 values were those of 7 against C. glabrata (1.23 µm), C. albicans and C. krusei (both 0.63 µm). Additionally, the synthesized compounds were evaluated for their in vitro cytotoxic effects on human mononuclear cells. As result, the cytotoxic activity of eugenol in eukaryotic cells decreased with the introduction of the morpholinyl group. Given these findings, we point out compounds 7 and 8 as the most promising derivatives because they showed potency values greater than those of eugenol and fluconazole and they also presented high selectivity indexes.