Phenolic metabolites from Pyrus calleryana and evaluation of its free radical scavenging activity

Investigation of the aqueous alcoholic extract of Pyrus calleryana Decne. leaves led to the isolation of two new phenolic acids glycosides, namely protocatechuoylcalleryanin-3-O-β-glucopyranoside (1) and 3′-hydroxybenzyl-4-hydroxybenzoate-4′-O-β-glucopyranoside (2), together with nine known compounds among them lanceoloside A and methylgallate, which have been isolated for the first time from the genus Pyrus. Structures of the isolated compounds were established by spectroscopic analysis, including UV, IR, HRESI-MS, and 1D/2D NMR. The total extract and some isolated compounds were determined against DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl radical, for their free radical scavenging activity, the total alcoholic extract showed strong antioxidant activity while the two new compounds showed weak antioxidant activity

Metformin, an Anthropogenic Contaminant of <i>Seidlitzia rosmarinus</i> Collected in a Desert Region near the Gulf of Aqaba, Sinai Peninsula

A phytochemical investigation of <i>Seidlitzia rosmarinus</i> collected along the shoreline of the Gulf of Aqaba in the remote southern desert region of the Sinai peninsula has revealed the presence of the registered drug metformin (<b>4</b>). However, analysis of the ¹⁴C content revealed the drug to be an anthropogenic contaminant. Consequently, natural product researchers should be aware that compounds isolated from plants might originate from environmental contamination rather than biosynthesis. The new natural product <i>N</i>-(4-hydroxyphenylethyl)<i>-</i>α<i>-</i>chloroferuloylamide was isolated as a mixture of the <i>E</i> and <i>Z</i> isomers along with a number of other well-established secondary metabolites

Metformin, an Anthropogenic Contaminant of <i>Seidlitzia rosmarinus</i> Collected in a Desert Region near the Gulf of Aqaba, Sinai Peninsula

A phytochemical investigation of <i>Seidlitzia rosmarinus</i> collected along the shoreline of the Gulf of Aqaba in the remote southern desert region of the Sinai peninsula has revealed the presence of the registered drug metformin (<b>4</b>). However, analysis of the ¹⁴C content revealed the drug to be an anthropogenic contaminant. Consequently, natural product researchers should be aware that compounds isolated from plants might originate from environmental contamination rather than biosynthesis. The new natural product <i>N</i>-(4-hydroxyphenylethyl)<i>-</i>α<i>-</i>chloroferuloylamide was isolated as a mixture of the <i>E</i> and <i>Z</i> isomers along with a number of other well-established secondary metabolites