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The aim of this study was to determine the antifungal activity of Drimenol (1) and its synthetic derivatives, nordrimenone (2), drimenyl acetate (3), and drimenyl-epoxy-acetate (4), and to establish a possible mechanism of action for drimenol. For that, the effect of each compound on mycelial growth of Botrytis cinerea was assessed. Our results showed that compounds 1 , 2 , 3 and 4 are able to affect Botrytis cinerea growth with EC 50 values of 80, 92, 80 and 314 ppm, respectively. These values suggest that the activity of these compounds is mainly determined by presence of the double bond between carbons 7 and 8 of the drimane ring. In addition, germination of B. cinerea in presence of 40 and 80 ppm of drimenol is reduced almost to a half of the control value. Finally, in order to elucidate a possible mechanism by which drimenol is affecting B. cinerea, the determination of membrane integrity, reactive oxygen species production and gene expression studies of specific genes were performed.

Phytophthora cinnamomi is a phytopathogen that causes extensive damage in different crops, and therefore, produces important economic losses all around the world. Chemical fungicides are a key factor for the control of this disease. However, ecological and environmental considerations, as well as the appearance of strains that are resistant to commercial fungicides, have prompted the quest for new antifungal agents which are of low ecological impact. In this work, a series of new 2-allylphenol derivatives was synthesized, and their structures were confirmed by FT-IR, NMR, and MS. Some of the synthesized compounds, more specifically nitro derivatives, exhibit strong growth inhibition of P. cinnamomi with EC50 as low as 10.0 &micro, g/mL. This level of activity is similar to that exhibited by METALAXYL MZ 58 WP, a commonly-used commercial fungicide, therefore, these compounds might be of agricultural interest due to their potential use as fungicides against P. cinnamomi. The results indicate that this activity depends on the chemical structures of the 2-allylphenol derivatives, and that it is strongly enhanced in molecules where nitro and hydroxyl groups adopt a -para configuration. These effects are discussed in terms of the electronic distribution of the aromatic ring induced by substituent groups.

Botrytis cinerea is a worldwide spread fungus that causes the grey mold disease, which is considered the most important factor in postharvest losses in fresh fruit crops. Consequently, the control of gray mold is a matter of current and relevant interest for agricultural industries. In this work, a series of phenylpropanoids derived from eugenol were synthesized and characterized. Their effects on the mycelial growth of a virulent and multi-resistant isolate of B. cinerea (PN2) have been evaluated and IC50 values for the most active compounds range between 31&ndash, 95 ppm. The antifungal activity exhibited by these compounds is strongly related to their chemical structure, i.e., increasing activity has been obtained by isomerization of the double bond or introduction of a nitro group on the aromatic ring. Based on the relationship between the fungicide activities and chemical structure, a mechanism of action is proposed. Finally, the activity of these compounds is higher than that reported for the commercial fungicide BC-1000 that is currently employed to combat this disease. Thus, our results suggest that these compounds are potential candidates to be used in the design of new and effective control with inspired natural compounds of this pathogen.

In this paper, we applied a curved-channel microfluidic device to separate DNA from PCR-inhibitor-containing water and simultaneously wash them into clean water for detection using a portable PCR thermocycler. Environmental DNA (eDNA) sampling has become an effective surveying approach for detecting rare organisms. However, low concentration eDNA molecules may be masked by PCR inhibitors during amplification and detection, increasing the risk of false negatives. Therefore, technologies for on-site DNA separation and washing are urgently needed. Our device consisted of a half-circle microchannel with a DNA-inhibitor sample inlet, a clean buffer inlet, and multiple outlets. By using the flow-induced inertial forces, 10 μm DNA-conjugated microparticles were focused at the inner-wall of the curved microchannel while separation from 1 μm inhibitor-conjugated microparticles and DNA washing were achieved simultaneously with the Dean flow. We achieved singleplex focusing, isolation and washing of 10 μm particles at an efficiency of 94.5 ± 2.0%. In duplex experiments with 1 μm and 10 μm particles, larger particles were washed with an efficiency of 92.1 ± 1.6% and a purity of 79 ± 2%. By surface-functionalizing the microparticles with affinity groups against Atlantic salmon DNA and humic acid (HA), and processing samples of various concentrations in our device, we achieved an effective purification and detection of DNA molecules using the portable PCR thermocycler. Our method significantly decreased PCR quantitation cycles from Cq > 38 to Cq = 30.35 ± 0.5, which confirmed enhancement of PCR amplification. The proposed device takes a promising step forward in sample preparation towards an integrated device that can be used for simultaneous purification and solution exchange of DNA in point-of-need environmental monitoring applications.