Cercel Radu, Paraschiv Mirela, Florica Cristina Stefania, Daescu Monica, Udrescu Adelina, Ciobanu Romeo C, Schreiner Cristina, Baibarac Mihaela
National Institute of Materials Physics, Atomistilor Street 405A, P.O. Box MG-7, 077125 Bucharest, Romania.
SC All Green SRL, 8 George Cosbuc Str., 700470 Iasi, Romania.
Pharmaceuticals (Basel). 2022 Mar 29;15(4):415. doi: 10.3390/ph15040415.
New aspects concerning the photodegradation (PD) of ampicillin are reported by photoluminescence (PL), Raman scattering and FTIR spectroscopy. The exposure of ampicillin in the absence (AM) and in the presence of the excipient (AMP) to UV light leads to an intensity diminution of the photoluminescence excitation (PLE) and photoluminescence (PL) spectra and the emergence of a new IR band at 3450 cm. The photoluminescence studies demonstrate that the AM PD is amplified in the presence of excipients and an alkaline medium. In this last case, the PD process of AM involves the emergence of new compounds, whose presence is highlighted by: (i) the emergence of the isosbestic point at 300 nm in the UV-VIS spectra; (ii) a change in the ratio between the absorbance of IR bands situated in the spectral ranges 1200-1660 and 3250-3450 cm; and (iii) a change in the ratio between the intensities of the Raman lines localized in the spectral ranges 1050-1800 and 2750-3100 cm. A chemical mechanism of the PD processes of AM in an alkaline medium is proposed.
通过光致发光（PL）、拉曼散射和傅里叶变换红外光谱（FTIR）报道了氨苄青霉素光降解（PD）的新情况。在不存在辅料（AM）和存在辅料（AMP）的情况下，氨苄青霉素暴露于紫外光下会导致光致发光激发（PLE）和光致发光（PL）光谱强度降低，并在3450 cm处出现新的红外波段。光致发光研究表明，在存在辅料和碱性介质的情况下，AM的PD会增强。在后一种情况下，AM的PD过程涉及新化合物的出现，其存在通过以下方式得以凸显：（i）紫外可见光谱中300 nm处等吸收点的出现；（ii）位于1200 - 1660和3250 - 3450 cm光谱范围内的红外波段吸光度之比的变化；以及（iii）位于1050 - 1800和2750 - 3100 cm光谱范围内的拉曼谱线强度之比的变化。提出了碱性介质中AM的PD过程的化学机制。
