Octanol–Water Partition Coefficients of Aristolochic Acids and Implications to the Etiology of Balkan Endemic Nephropathy

Determination of Aristolochic Acids in Vegetables: Nephrotoxic and Carcinogenic Environmental Pollutants Contaminating a Broad Swath of the Food Supply and Driving Incidence of Balkan Endemic Nephropathy

“…The analysis revealed a significantly higher log K ow value of AA-I than of AA-II. At all the different pHs tested, AA-I was found with log K ow values ∼0.3 units (2 K ow units) larger than that of AA-II, which is similar to that observed by Tangtong . We believe this observed difference can be attributed to the stronger acidity of AA-II than AA-I, stemming from a higher ionization efficiency promoting AA-II to the deprotonated carboxylate ion form and favors a higher partitioning coefficient in the aqueous phase. , In other words, at the same pH above their p K a , a larger proportion of AA-I than AA-II molecules will be protonated and more octanol soluble.…”

“…The K ow of AA-I and AA-II at different pH was determined in accordance with the shake-flask method. − In brief, 10 μL of the AA standard mixture (AA-I = 1.6 μM, AA-II = 1.7 μM) in methanol was added to polypropylene tubes containing 0.5 mL of octanol and 1 mL of phosphate buffer (5 mM) at different pH (pH 5.7 to pH 8; n = 3). The sample mixtures were then shaken at 200 rpm at room temperature for 24 h using an orbital-shaker before being centrifuged at 5000 rpm for 10 min to facilitate phase separation of the organic and aqueous layers.…”

Aristolochic acid I as an emerging biogenic contaminant involved in chronic kidney diseases: A comprehensive review on exposure pathways, environmental health issues and future challenges

“…On the other hand, the hydroponic study revealed a pH-dependent accumulation of AAI in different parts of the plant, with higher AAI concentrations detected in plants cultivated in an acidic environment, which is consistent with the octanol/water partition coefficient studies (Au et al, 2020;Tangtong et al, 2020). Overall, these findings showed that the level of AAI absorption and its subsequent distribution to underand above-parts of food crops is correlated with the pH of the environment (Au et al, 2020;Tangtong et al, 2020).…”

“…The follow-up study was conducted on soil samples from endemic and non-endemic wheat and maize fields in Serbia during the harvest time. In the endemic area, soil samples from the wheat field had a 1.5 higher concentration of AAI compared to the soil samples collected from the maize field (Tangtong et al, 2020).…”

“…There are some other experimental studies, performed by Tangtong et al (2020), which offer explanations on AAI behaviour in the soil media at different pH values (5.5-8). The results revealed that log Kow decreased with increasing pH.…”