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This is the first phytochemical study of Blakiella bartsiifolia, an endemic species of Mérida. From the foliar exudates two flavonoids ((5,4´-dihydroxy-3,6,7,3´-tetramethoxyflavone; 5,7,4´-trihydroxy-3,8,3´-trimethoxy-flavone) and a labdane diterpene (labda-7,14-dien-13(S)-ol) were identified by high field NMR spectroscopy. Plants naturally exposed to direct sunlight possessed a significantly higher specific absorbance coefficient in the UV region than plants growing in shaded areas.

ABSTRACT Introduction Bracken ( Pteridium spp) illudane glycosidess are labile biologically active terpenoids that undergo decomposition in mild alkali or acid, heat and enzymatic reactions. Hypothetically, quantitation of these weakly chromophoric carcinogens may be challenged by plant sample preparation procedures that may alter the yield of isolates. Objective To study the influence of common plant sample pre-treatments on the recovery of Pteridium caudatum illudane glycoside carcinogens, ptaquiloside (1a), caudatoside (1c) and ptaquiloside Z (1d), and associated pterosins A, B and Z (2a, b, c) using HPLC-DAD. Method Bracken fronds were divided in equal left/right sections. One section was subjected to high vacuum desiccation (VD) and the other to freeze-drying (FD), air drying at room temperature (AD) for 7 days, air drying at 70 °C for 72 h (HD), or no treatment (fresh frond, FF). Quantitation was achieved by brief hot-water extraction, base-acid transformation of 1a, 1c and 1d to 2a, b, c and HPLC-DAD analysis against standards. Results Substantial differences in extraction yields were found for all illudane glycosides in the order FF > FD ≈ VD > AD > HD. Illudane instability to HD was 1c > 1d > 1a. Significant losses also were recorded in yields of Pterosins A, B and Z. Conclusion Glycoside extraction suffers from substantial yield loss of all illudane glycosides and indigenous pterosins in all sample pre-treatments studied relative to fresh frond material. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sugary solution intake behavior by Odontomachus chelifer (Latreille), is studied. The feeding mechanism involved is described. Effects of sucrose concentration and solution viscosity on ingested load, feeding time and rate of liquid intake are assessed. Suction was always the feeding mechanism, regardless of concentration or viscosity of the solution. There were no differences in loads ingested for concentrations of up to 30% w/w, but feeding took longer at this concentration. Liquid intake rates were higher at the lowest concentrations. Above 40% w/w, values of all three variables were smaller. O. chelifer's ability to ingest mildly viscous fluids could be related to its capacity to ingest other viscous fluids present in its diet. [ABSTRACT FROM AUTHOR]