(-)-Camphene-Based Derivatives as Potential Antibacterial Agents against Staphylococcus Aureus and Enterococcus Spp.

Abstract

Aim: To evaluate the activity of (-)-camphene-based thiosemicarbazide (TSC) and 4-hydroxy-thiosemicarbazone (4-OH-TSZ), alone and in combination against Gram-positive. Material & methods: MIC were determined for Staphylococcus aureus, Enterococcus spp. reference strains and clinical isolates. Drug combination, time–kill and cytotoxicity assays were also performed. Results: TSC and 4-OH-TSZ demonstrated potent inhibitory activity against S. aureus and Enterococcus spp., including multidrug-resistant isolates (MIC ranging from 1.9 to 31.2 μg/ml), and were bactericidal for the reference strains of both Gram-positive tested. The derivatives proved to be selective for the bacteria and synergistic with oxacillin and vancomycin. Conclusion: (-)-Camphene-based derivatives can represent promising drug candidates against critical pathogens, such as S. aureus and Enterococcus spp., including MRSA and vancomycin resistance Enterococcus spp. isolates.

In vitro antiproliferative and apoptotic effects of thiosemicarbazones based on (-)-camphene and R-(+)-limonene in human melanoma cells

“…Of the 19 compounds selected, 9 were novel compounds (compounds 8 , 11 , 15 , 18 , 20 , 22 , 25 , 26 , and 31 ), which have not been previously reported in the literature. The remaining 10 compounds listed in Table 1 were previously evaluated for different activities, such as antibacterial activity [ 19 ], anti- Mycobacterium tuberculosis activity [ 20 ], antileishmanial activity [ 20 ], or anticancer activity against other tumor cell lines [ 21 ].…”

“…Among these, the syntheses of benzaldehyde -(-)- camphene-based ( 4 ), p - methoxy ( 6 ), o - chloro ( 7 ), p - chloro ( 9 ), p - nitro ( 12 ), p - dimethylamine ( 13 ) and p - hydroxy ( 14 ) were previously published, and the compounds were evaluated for anti- Mycobacterium tuberculosis , Staphylococcus aureus and Enterococcus spp. activity [ 19 , 20 ]. The remaining compounds ( 5, 8, 10, 11 ) synthesized by da Silva et al [ 24 ], are still unpublished and are highlighted in bold in Fig 1 .…”

Chemical Composition Determination and Evaluation of the Antimicrobial Activity of Essential Oil from Croton blanchetianus (Euphorbiaceae) against Clinically Relevant Bacteria

“…(+)‐α‐pinene showed inhibitory activity (4.150 μg/mL) and bactericidal activity after incubation (6 h) with S. aureus (MRSA) [16] . Other compounds found in C. blanchetianus EO also demonstrate antimicrobial activity, as camphene, β‐pinene, myrcene, δ‐3‐Carene, limonene, p‐ cymene, α‐terpineol among others [17–23] …”

In-Vitro and In-Vivo Antibacterial Effects of Frankincense Oil and Its Interaction with Some Antibiotics against Multidrug-Resistant Pathogens

“…Limonene is reported to have an antibacterial effect against S. aureus and P. aeruginosa and also potentiated the effect of gentamicin in-vitro [ 42 ]. Camphene is also reported for antibacterial effect against S. aureus and Enterococcus species [ 43 ], while myrcene is reported for activity against S. aureus and food-borne pathogens [ 44 ]. Though individual components are known to be effective, it is believed that microbial resistance will not occur against the essential oils because the oil contains several constituents with antimicrobial effects [ 45 ].…”