No abstract

Arbutin and methylarbutin as well as their aglycones, hydroquinone, and hydroquinone monomethyl ether, were isolated and identified in the aqueous alcoholic extract of Origanum majorana L. Arbutin was estimated quantitatively by chromatospectrophotometric and HPLC techniques. It was also found that hydroquinone shows a potent cytotoxicity on cultured rat hepatoma cells (HTC).

No abstract

The reaction of (E)-or (Z)-5-ylidene-1,3-dioxan-4-one (1) and 2-bromothiophenol, followed by bromo-lithium exchange with nBuLi, provides a new access to optically active thiochroman-4-ones 4 and 5. Stereoselective conjugate addition occurs in the first step and the resulting 5-(1-phenylsulfanylalkyl)-1,3-dioxan-4-ones 2 and 3 undergo ring transformation to thiochroman-4-ones by attack of the lithiated phenyl