The antibacterial effect of a polyhydroxylated fucophlorethol from the marine brown alga,Fucus vesiculosus

An antibacterial compound was isolated from the brown alga Fucus vesiculosus. Purification consisted of extraction of plant material with 0.05% trifluoroacetic acid, concentration on a C₁₈ cartridge, and reverse-phase high performance liquid chromatography on a C₁₈ semi-preparative column. The isolated compound exhibited antibacterial activity against both the Gram-positive and the Gram-negative bacteria tested. Killing studies conducted indicated that the activity was bactericidal. The compound showed no haemolytic effect against human red blood cells. Results obtained by electrospray ionization mass spectrometry indicated that the antibacterial activity was caused by a polyhydroxylated fucophlorethol.     

Antifungal and Insecticidal Activities of Selected Plant Species from Cloud Forest of Veracruz,Mexico: A Contribution to the Search of Novel Control Agents against Ambrosia Pest Complexes

The antifungal and insecticidal activities of 34 extracts from 27 plant species were evaluated against fungal phytopathogens of the genus Fusarium and Xyleborus Scolytine ambrosia beetles involved in Fusarium dieback (FD) and laurel wilt (LW) diseases. Sixteen extracts caused mycelial growth inhibition (MGI) above 23 % at 2 mg mL⁻¹ against F. solani, those from S. nudum and M. argyrophylla exhibited the highest MGI (57 % and 49 %, respectively). Thirteen extracts displayed significant antifungal activity against F. kuroshium, those from C. nocturnum and M. argyrophylla exhibited the highest MGI (100 % and 54.9 %, respectively). Additionally, ten plants extracts caused mortality in at least one of the beetle species tested, mainly from Solanaceae species. In the most active species, 39 phenolics were identified that may have contributed to their biological effects. This study is one of the first to report the potential of plant-derived natural products against the causative agents of FD and LW.