Parthenin: targeted isolation, characterisation and its application as a fluorescent probe for ammonia sensing

Natural products representing an important class of organic compounds exhibiting immense potential applications. Keeping in view of diverse applications of natural products we have isolated parthenin compound from Parthenium hysterophorosus using column chromatography. The extracted compounds were subjected to initial screening through FT-IR spectroscopy depicting the presence of different functionalities in the compound. The compound have been screened for optical studies in solid phase depicting the presence of transitions (π–π and n–π) with characteristics optical band gap of 2.3 eV. The thermal studies indicate that the compound is anhydrous and stable upto 300°C beyond which degradation starts. The compound being soluble in various polar and non-polar solvents were investigated for solvatochromism and it has been observed that polar solvents enhances the absorption behaviour compared to non-polar solvents which include water, MeOH, DMF, the λmax corresponding to water, MeOH and DMF are depicted as 290, 230 and 270 nm, respectively. The compound were explored for the sensing of NH3 molecule for which the limit of detection was 1.2 × 10−3 M. The isolated compound were characterised by 1H and 13C-NMR spectroscopy.

天然产物是一类重要的有机化合物，具备广阔的应用潜力。鉴于天然产物多样的应用场景，本研究通过柱色谱法从银胶菊（Parthenium hysterophorosus）中分离得到银胶菊素（parthenin）。通过傅里叶变换红外光谱（FT-IR）对提取所得的化合物进行初步表征，确认其分子中存在多种官能团。对该化合物开展固相光学性能研究，结果显示其存在π-π与n-π电子跃迁，特征光学带隙为2.3 eV。热性能研究结果表明，该化合物为无水形态，在300℃以下具有良好热稳定性，超过该温度后即发生降解。鉴于该化合物可溶于多种极性与非极性溶剂，本研究对其溶剂致变色效应进行了探究：相较于非极性溶剂，极性溶剂可增强其吸收性能，所涉溶剂包括水、甲醇（MeOH）与N,N-二甲基甲酰胺（DMF）；水、甲醇与DMF对应的最大吸收波长（λmax）分别为290 nm、230 nm与270 nm。此外，本研究还探究了该化合物对氨气（NH3）分子的传感性能，其检出限为1.2 × 10^-3 mol/L。所分离得到的化合物通过核磁共振氢谱（1H-NMR）与碳谱（13C-NMR）完成了结构表征。