Periodontal disease (PD) is complex polymicrobial disease which destroys tooth-supporting tissue. Although various synthetic inhibitors of periodontitis-triggering pathogens have been recognized, their undesirable side effects limit their application. Hence, the present study intended to perform the synthesis, characterization, antimicrobial evaluation, and cytotoxicity analysis of novel benzamidine analogues (NBA). This study involved the synthesis of novel imino bases of benzamidine (4a–c), by reacting different aromatic aldehydes with 2-(4-carbamimidoylphenoxy) acetohydrazide (3), which was synthesized by the hydrazination of ethyl 2-(4-carbamimidoylphenoxy) acetate (2), the derivative of 4-hydroxybenzene carboximidamide (1). This was followed by characterization using FTIR, 1H, 13C NMR and mass spectrometry. All synthesized compounds were further tested for antimicrobial potential against PD-triggering pathogens by the micro broth dilution method. The cytotoxicity analysis of the NBA against HEK 293 cells was conducted using an MTT assay. The present study resulted in a successful synthesis of NBA and elucidated their structures. The synthesized NBA exhibited significant antimicrobial activity values between 31.25 and 125 µg/mL against tested pathogens. All NBA exhibited weak cytotoxicity against HEK 293 cells at 7.81 µg, equally to chlorhexidine at 0.2%. The significant antimicrobial activity of NBA against PD-triggering pathogens supports their potential application in periodontitis treatment.

Periodontal disease (PD) is multifactorial oral disease that damages tooth-supporting tissue. PD treatment includes proper oral hygiene, deep cleaning, antibiotics therapy, and surgery. Despite the availability of basic treatments, some of these are rendered undesirable in PD treatment due to side effects and expense. Therefore, the aim of the present study is to develop novel molecules to combat the PD triggering pathogens. The study involved the synthesis of 4-((5-(substituted-phenyl)-1,3,4-oxadiazol-2-yl)methoxy)benzamidine (5a-e), by condensation of 2-(4-carbamimidoylphenoxy)acetohydrazide (3) with different aromatic acids; and synthesis of 4-((4-(substituted benzylideneamino)-4H-1,2,4-triazol-3-yl)methoxy)benzamidine (6a-b) by treatment of compound 3 with CS2 followed by hydrazination and a Schiff reaction with different aromatic aldehydes. Synthesized compounds were characterized based on the NMR, FTIR, and mass spectrometric data. To assess the effectiveness of the newly synthesized compound in PD, new compounds were subjected to antimicrobial evaluation against P. gingivalis and E. coli using the micro-broth dilution method. Synthesized compounds were also subjected to cytotoxicity evaluation against HEK-293 cells using an MTT assay. The present study revealed the successful synthesis of heterocyclic derivatives of benzamidine with significant inhibitory potential against P. gingivalis and E. coli. Synthesized compounds exhibited minimal to the absence of cytotoxicity. Significant antimicrobial potential and least/no cytotoxicity of new heterocyclic analogs of benzamidine against PD-triggering bacteria supports their potential application in PD treatment.

Gingipains (RgpA, RgpB, and Kgp) are major virulence factors of the periodontitis-causing bacterium Porphyromonas gingivalis. Isolation of gingipains from the crude protein sample of P. gingivalis is critical for studying the underlying invasion mechanism that contributes to periodontitis, Alzheimer’s disease, and cardiovascular disease (CVD). Chromatographic processes and molecular cloning are two standard techniques often used for gingipains isolation, which are time-consuming and costly. In this study, considerably easier methods based on passive-mediated diffusion gel elution and gelatin zymogram were used to isolate and characterize gingipains. Importantly, proteins eluted from Native-PAGE showed enzymatic activity for both Rgp and Kgp. In gelatin zymography, the proteins with a molecular size of ~50 kDa and above 245 kDa were suggested as arginine-specific gingipains. The passive diffusion-mediated gel elution method is a simpler technique to isolate gingipains from crude protein samples of P. gingivalis. By using covalent and highly specific gingipain inhibitors, gelatin zymography enabled an individual characterization of gingipain activity and inhibition. Finally, this protocol can be easily extended by adding the isoelectric focusing to further improve the protein separation and characterization.

Periimplantitis (PI) is complex polymicrobial disease, which destroys implant-supporting tissue. Although facts suggest several synthetic inhibitors of periimplantitis causing bacteria (PCB), but the undesirable side effects of them limits their application. Hence, current investigation was intended to carry out the synthesis, characterization, in vitro antimicrobial evaluation and cytotoxicity (cell viability) analysis of new benzamidine derivatives (NBDs) against periimplantitis causing bacteria. Present study involved synthesis of 2-(4-((4-substituted)carbamothioyl)phenoxy)-N-(4-substituted benzylidene)acetohydrazide (4a-c) by treatment of different aromatic aldehydes with 2-(4-carbamothioylphenoxy)acetohydrazide (3), that was obtained by hydrazination of ethyl 2-(4-carbamothioylphenoxy)acetate (2), the derivative of 4-hydroxybenzothioamide (1). The synthesized compounds (NBDs) were subjected to FTIR, 1H NMR, 13C NMR and mass spectrometric characterization. All NBDs were further investigated for their antimicrobial potential (MIC and MBC) against P. gingivalis the PCB, using micro-broth dilution method. The NBDs were also tested for their cytotoxicity (cell viability) against HEK 293 cells using MTT assay. The present study successfully synthesized and elucidated the structures of the synthesized NBDs. The NBDs when tested against P. gingivalis exhibited MIC ranging between 62.5-500 μg/mL, whereas NBDs 4a and 4b exhibited MBC of 125 and 62.5 μg/mL respectively. Also, all NBDs exhibited weak cytotoxicity (cell viability more than 80%) against HEK 293 at 7.81 μg/mL. The significant antimicrobial activity of NBDs and higher cell viability (safety) against P. gingivalis supports their potential application in periimplantitis treatment, however these NBDs must be further investigated for the additional in vivo and clinical studies.

World Health Organization (WHO) report suggests that dengue the life-threatening disease currently has no specific medication. Hence, present study was intended to synthesize some new nucleoside analogues (NNAs) to combat the dengue virus (DENV-2). Study involved synthesis of 1-(4-((substituted cyclohexyl)methyl)-2-(3,4-dihydroxy-5-(hydroxymethyl)-tetrahydrofuran-2-yl)-3,5-dihydroxy-1,2,4- triazinan-1-yl)ethanone (3a-f) by hydrogenation and acetylation of 4-((substituted-cyclohexa-2,5- dienylidene)methyl)-2-(3,4-dihydroxy-5-(hydroxymethyl)-tetrahydrofuran-2-yl)-1,2,4-triazine- 3,5(2H,4H)-dione (3a-f), that was synthesized by treating uridine derivative (1) with various substituted aldehydes. The structures of newly synthesized NNAs were characterized using NMR, FTIR and mass spectrometric data. Effectiveness of the synthesized NNAs against dengue was also evaluated based on their anti-dengue activity using DENV-2 serotype and cytotoxicity evaluation against Vero cells using MTT assay. Present study reports successful synthesis of NNAs 3a-f with high inhibition potential against DENV-2 and minimal to absence of cytotoxicity. Significant anti-dengue activity and least/no cytotoxicity of NNAs against DENV-2 supports their potential application in dengue treatment. However, synthesized NNAs should be further evaluated for preclinical and clinical significance.