Toxins from the posterior salivary gland (PSG) of cuttlefishes are known toxins with pronounced toxicity. In the present study, ionic peptide rich PSG toxin from the cuttlefish S. pharaonis was isolated by ion exchange chromatography and purified by Reversed Phase High Performance Liquid Chromatography (RP-HPLC), with active fraction at a retention time of 26 min. The net protein content of the PSG toxin was estimated to be 46.6 mg at a proximate molecular weight of ∼ 50 kDa. Fourier Transform Infrared Spectroscopy (FT-IR) of PSG toxin revealed the presence of alcoholic OH, primary NH, alkyl CH and conjugated CONH functional groups. Circular Dichroism (CD) spectroscopy and K2D analysis of the PSG toxin confirmed the presence of secondary structure with 36.77% α-helix,12.31% β sheet and 50.92% random coil. Scanning Electron Microscopy (SEM) of the PSG toxin eluted amberlite IRA 900 Cl⁻ resin showed surface abrasion and corrosive blebbing. Energy Dispersive X-ray Spectrometry (EDX) analysis of PSG toxin treated resin revealed increase in nitrogen and sulphur content corresponding to amino acid composition. Teratogenicity of PSG toxin against Zebrafish embryo demonstrated developmental malformations and premature hatching at a maximum tolerated dose of 1.25 μM. The PSG toxin (50 μM) exhibited commendable inhibitory activity with pronounced zone of inhibition against gram E. coli (10 mm) and K. pneumonia (10 mm). The results strongly demonstrate the toxicity of the ionic peptide rich PSG toxin from S. pharaonis and its exploitation for its promise as a potential antibacterial agent of the future.

来自墨鱼后唾液腺（PSG）的毒素是已知具有明显毒性的毒素。在本研究中，通过离子交换色谱法分离了墨鱼链球菌中富含离子肽的PSG毒素，并通过反相高效液相色谱（RP-HPLC）进行了纯化，其中活性成分的保留时间为26分钟。在大约50 kDa的近分子量下，PSG毒素的净蛋白质含量估计为46.6 mg。PSG毒素的傅立叶变换红外光谱（FT-IR）显示存在醇性OH，伯NH，烷基CH和共轭CONH官能团。圆二色谱（CD）光谱和PSG毒素的K2D分析证实了二级结构的存在，α-螺旋为36.77％，β片为12.31％，无规卷曲为50.92％。洗脱AMBERLITE IRA 900 Cl为基准的PSG毒素的扫描电子显微镜（SEM）^-树脂显示表面磨损和腐蚀性起泡。经PSG毒素处理的树脂的能量色散X射线光谱（EDX）分析表明，氮和硫的含量增加，与氨基酸组成相对应。PSG毒素对斑马鱼胚胎的致畸性显示发育畸形和最大允许剂量1.25μM的早孵化。PSG毒素（50μM）表现出可观的抑制活性，并具有明显的革兰氏大肠杆菌（10 mm）和肺炎克雷伯氏菌（10毫米）。该结果有力地证明了来自法老葡萄球菌的富含离子肽的PSG毒素的毒性，并为其作为未来潜在的抗菌剂的前景进行了开发。