Masking of a malodorous substance on 1,2-dioleoyl-sn-glycero-3-phosphocholine molecular layer

Abstract The performance of a trans-2-nonenal (NE)-including 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) molecular layer as a model of epithelial cellular membrane damaged by malodorous substance was investigated to understand the masking effect of odorants (benzaldehyde (BA), cyclohexanecarboxyaldehyde (CA), p-anisaldehyde (AA), and 4-methoxy-cyclohexanecarbaldehyde (MA)). The surface pressure of the DOPC monolayer increased upon the addition of NE, and the surface pressure–area isotherm of the DOPC-NE mixture was characteristically responsive to the odorants (BA, CA, AA, and MA). Differential scanning calorimetry, Fourier-transform infrared spectroscopy, and ultraviolet absorption spectrophotometry were conducted to evaluate the interactions among DOPC, NE, and the odorants. The results suggested that odorants with an aromatic ring form a complex with NE and were eliminated from the DOPC membrane. We found that odorants with an aromatic ring play an important role in inducing the masking effect on the DOPC-NE mixed monolayer because of the characteristic interactions between NE and odorant.