Dereplication Tools for Rhizophora mangle Extracts from Different Mangrove Areas and their Potential Against Staphylococcus aureus.

Rhizophora extracts have several potential biological activities, and their metabolites can be used in the pharmaceutical industry. Extracts of Rhizophora species obtained from mangroves have shown prospective activity against Staphylococcus aureus. This study aimed to investigate the chemical profile of Rhizophora mangle leaves from fringe, basin, and transition mangrove zones and their bactericidal/bacteriostatic potential against S. aureus. R. mangle leaves were collected monthly in 2018 from litterfall in three different zones of the mangrove of Guaratiba State Reserve: fringe, basin, and transition. Extracts were prepared from the material collected in October and December for LC-HRMS/MS analysis, and dereplication was performed using a molecular library search and the classical molecular networking GNPS platform. The minimum inhibitory concentrations (MICs) of the aqueous extract of R. mangle against S. aureus were determined. No S. aureus growth was observed compared to the control for extracts collected from September to December. Different compounds were annotated in each region, yet a marked presence of phenolic compounds was noted, among them glycosylated flavonoid derivatives of quercetin and kaempferol. The results suggest bactericidal/bacteriostatic activity for extracts of R. mangle leaves collected in 2018 from three mangrove forest zones.

Assessment of brazilian mangroves hydrocarbon contamination from a latitudinal perspective.

The present study investigated the contamination of Brazilian mangroves sediments by aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs). Samples were obtained from mangroves located along the brazilian coast, between the northern coast and the austral limit of the occurrence of this ecosystem. Total AH ranged from 1.9 to 311.3 µg g-1 and compound distribution pointed to biogenic sources, mainly from mangrove forests, and petrogenic sources, with a significant presence of an unresolved complex mixture in some areas. PAH values (34.4-977.3 ng g-1) indicated low to moderate contamination levels in mangrove sediments, reflecting the socioeconomic diversity observed along the Brazilian coast. The predominant PAH sources ranged from pyrolytic to petrogenic. According to sediment quality reference values, the evaluated sediments are not likely to cause biological effects, but deserve attention due to the current expansion scenario of oil prospecting activities off the Brazilian coast.