Azadirachta indica A. Juss, known as neem (Meliacea family), has insecticide and pesticide properties, and many studies have shown their efficacy as antifungal, anti -inflammatory, among others. Studies for the development of drugs from plants are rising due to several factors such as bacterial resistance, indiscriminate use and the adverse reactions of antibiotics. In this study, phytochemical triage and thin layer chromatography analysis were performed, with similar results as the presence of flavonoids, tannins and terpenes. The antimicrobial activity showed that the ethyl acetate extract and butanol fraction presented greater activity against Streptococcus mutans and Streptococcus mitis presenting a MIC = 50 µg/ml for these strains, and the strain Enteroccocus faecalis, the hydroethanolic extract and aqueous fraction were most promising samples with a MIC = 50 µg/ml and MIC = 25 µg/ml, respectively. Therefore, it encourages the continuation of studies, aiming at the devel opment of cosmetics or toothpaste.

The main pathogen underlying citrus variegated chlorosis (CVC), a citrus fruit disease, is Xylella fastidiosa, a Gram‐negative s‐shaped bacterium that blocks water and nutrient circulation. Discovering new pesticides to combat CVC have become a challenge. Research into essential oils (EOs) is crucial because these substances can be potentially useful in pest control. This study aims to determine minimum inhibitory concentrations (MIC), to investigate biofilm inhibition capacities through MBIC50 analysis, and to evaluate synergistic effects with streptomycin of 17 EOs against X. fastidiosa. This study also analyses the chemical profiles of the EOs that provided the best antibacterial activity results. The MIC values of the EOs ranged from 125 to 1,000 µg/ml. Analysis of the MICB50 values of the sandalwood and patchouli EOs revealed biofilm inhibitory activity. No synergistic effects were evident for streptomycin combined with the sandalwood or patchouli EOs: ΣFIC was 1.25 and 1.5, respectively, which denoted indifference. We detected α‐gurjunene (27.6%), patchouli alcohol (21.6%), α‐bulsene (17.3%) and α‐patchoulene (6.3%) as the major patchouli EO constituents. On the basis of our results, the sandalwood and patchouli EOs present antibacterial action and are promising natural sources for the development of new pesticides against X. fastidiosa.

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