A New Facile Synthesis of D4-Pterosin B and D4-Bromopterosin, Deuterated Analogues of Ptaquiloside

Abstract

Ptaquiloside (Pta) is a potent carcinogen present in bracken fern and in soil matrices, that can potentially leach to the aquatic environment. More recently its presence in the milk of different farm animals has been reported. Pterosin B (Ptb) and bromopterosin (BrPt) represent the most convenient analogues in the detection of ptaquiloside by mass spectrometry. Pterosin sesquiterpenes are also involved in many patented biomedical protocols. In this work we introduce a new and convenient approach to the synthesis in three steps and more than 80% yield of d 4 -pterosin B (d 4 -Ptb) and d 4 -bromopterosin (d 4 -BrPt), useful as internal standards in the quantification of ptaquiloside.

Ptaquiloside, the Major Carcinogen of Bracken Fern, in the Pooled Raw Milk of Healthy Sheep and Goats: An Underestimated, Global Concern of Food Safety

“…Polyethylene frits (20 μm) were included. d 4 -Bromopterosine, used as an internal standard in the calibration procedure, was synthesized according to a recent protocol . Solutions of deuterated standard were prepared in methanol or ethyl acetate and stored at −20 °C.…”

Natural sesquiterpenoids

“…246 A facile synthesis of deuterated pterosin B has been described. 247 Known africanane sesquiterpenes have been identied as components of Sinularia numerosa. 248 A total synthesis of (+)-asteriscanolide has been reported.…”

Secondary Metabolites (Pterosin F and B) From Pteridium aquilinum

“…It has not been earlier established whether pterosin F is synthesized or it is a product of a metabolic precursor activated in leaves of P. aquilinum. Several studies suggest that pterosin B is formed from ptaquiloside by decomposition in presence of light [1]. It is possible that ptaquiloside is a source for pterosin B in leaves.…”

“…It is possible that ptaquiloside is a source for pterosin B in leaves. Another compound indanone-type of compounds, pterosin A, was isolated from fern and we took into consideration that its precursor is also ptaquiloside, named dennstoside [1].…”