Synthesis and Biological Activities of Camphor Hydrazone and Imine Derivatives

Abstract

Both sonochemical and classical methodologies have been employed to convert camphor, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one, C9H16C=O, into a number of derivatives including hydrazones, C9H16C=N-NHAr 3, imines, C9H16C=N-R 7, and the key intermediate nitroimine, C9H16C=N-NO2 6. Reactions of nitroamine 6 with nucleophiles by classical methods provided the desired compounds in a range of yields. In evaluations of activity against Mycobacterium tuberculosis, compound 7j exhibited the best activity (minimal inhibitory concentration (MIC) = 3.12 µg/mL), comparable to that of the antitubercular drug ethambutol. The other derivatives displayed modest antimycobacterial activities at 25–50 µg/mL. In in vitro tests against cancer cell lines, none of the synthesized camphor compounds exhibited cytotoxic activities.

Monoterpenes and Their Derivatives—Recent Development in Biological and Medical Applications

“…The next example, showing the use of naturally occurring camphor as a substrate, led to obtaining imines 100 – 102 , and also hydrazones 103 – 105 , which belong to R , R -(+)-camphor derivatives [ 95 ]. Figure 26 presents a few selected examples from a large set of synthesized compounds.…”

“…Commonly mentioned examples are derivatives of benzimidazole, benzoxazole, and benzothiazole, which possess a wide range of biological effects, mainly antiulcer, anti-inflammatory, antiviral activity, antihypertensive, and analgesic [ 111 , 112 , 113 , 114 ]. On the other hand, the presence of 1,7,7-trimethylbicyclo[2.2.1]heptane scaffold of designed molecules induces many biological activities of prepared compounds, for instance high inhibitory activity of molecules on the replication of influenza A virus [ 88 , 94 , 95 ]. Hence, works where the compounds containing those two structural elements are broadly tested and significant biological activity are demonstrated.…”

Synthesis and In Silico Study of Some New bis-[1,3,4]thiadiazolimines and bis-Thiazolimines as Potential Inhibitors for SARS-CoV-2 Main Protease

“…In addition, bis -thiazole pharmacophores were reported to reveal various biological activities such as anti-inflammatory, analgesic, anti-ulcerogenic [ 11 ], antiviral [ 12 ], antimicrobial [ 13 , 14 ], antioxidant [ 15 ], and anticancer activities [ 16 , 17 , 18 , 19 ]. Moreover, azoles tethered imines are accentuated to investigate new potential drug candidates with diverse therapeutic efficacy such as antibacterial, antimicrobial, antifungal, anticancer, antioxidant, and antiproliferative activities [ 20 , 21 , 22 , 23 , 24 , 25 ]. So, molecular hybridization of imines and azoles is a beneficial approach to structural alteration, as a single species of two or more pharmacophores can serve as potential COVID-19 drug candidates [ 26 ].…”

Evaluation of pure camphor (C10H16O) against wild-caught Culex quinquefasciatus larvae in East Jakarta, Indonesia: Detoxification enzymes and histopathological midgut

“…Camphor (C10H16O, monoterpene) is a volatile, aromatic, crystalline monoterpene ketone derived from Cinnamomum camphora wood or synthesized from turpentine [16] . Camphor also had insecticidal anti-inflammatory, antimicrobial, analgesic, anticonvulsant, antiviral, antituberculosis, anticancer, and antioxidant properties [16][17][18] . Comphor compounds are essential oil compounds found in plants such as Cinnamomum camphora [19] , Rosamary officinalis [20] , and others.…”