In the study presented here, the nucleophilic substitution reaction of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide was carried out with different alkyl/aralkyl halides (5a-r) to form its different S-substituted derivatives (6a-r), as depicted in scheme 1. The structural confirmation of all the synthesized compounds was done by IR, 1H-NMR, 13C-NMR and CHN analysis data. Bacterial biofilm inhibitory activity of all the synthesized compounds was carried out against Bacillus subtilis and Escherichia coli. The anticancer activity of these molecules was ascertained using anti-proliferation (SRB) assay on HCT 116 Colon Cancer Cell lines while the cytotoxicity of these molecules was profiled for their haemolytic potential. From this investigation it was rational that most of the compounds exhibited suitable antibacterial and anticancer potential along with a temperate cytotoxicity.
We previously developed a new zinc(II) phthalocyanine (ZnPc) derivative (Pc 1) conjugated to poly-L-glutamic acid (PGA) (1-PG) to address the limitations of ZnPc as part of an antitumor photodynamic therapy approach, which include hydrophobicity, phototoxicity, and nonselectivity in biodistribution and tumor targeting. During this study, we discovered that 1-PG possessed high near-infrared (NIR) light absorptivity (λmax = 675 nm), good singlet oxygen generation efficiency in an aqueous environment, and enhanced photocytotoxic efficacy and cancer cell uptake in vitro. In the current study, we discovered that 1-PG accumulated in 4T1 mouse mammary tumors, with a retention time of up to 48 h. Furthermore, as part of an antitumor PDT, low dose 1-PG (2 mg of Pc 1 equivalent/kg) induced a greater tumor volume reduction (-74 ± 5%) when compared to high dose ZnPc (8 mg/kg, -50 ± 12%). At higher treatment doses (8 mg of Pc 1 equivalent/kg), 1-PG reduced tumor volume maximally (-91 ± 6%) and suppressed tumor size to a minimal level for up to 15 days. The kidney, liver, and lungs of the mice treated with 1-PG (both low and high doses) were free from 4T1 tumor metastasis at the end of the study. Telemetry-spectral-echocardiography studies also revealed that PGA (65 mg/kg) produced insignificant changes to the cardiovascular physiology of Wistar-Kyoto rats when administered in vivo. Results indicate that PGA displays an excellent cardiovascular safety profile, underlining its suitability for application as a nanodrug carrier in vivo. These current findings indicate the potential of 1-PG as a useful photosensitizer candidate for clinical PDT.