In memory of Stanislav Valentinovich Kruglov (1947–2010)

Obituary

In memory of Stanislav Valentinovich Kruglov (1947–2010)     

In Memoriam: Dr. John M. Laflen

The soil erosion research and soil and water conservation global community lost a treasured member on November 20, 2020, when Dr. John Matthew Laflen (Fig. 1) died. Always one with a friendly welcoming smile, John had hundreds of friends, both personally and professionally throughout the world. This article includes many of his professional and scientific contributions, and impacts from his research and outreach activities.     

Call for Papers-GMO Biosafety Research（ISSN 1925-1955）

GMO Biosafety Research (ISSN 1925-1955) is a new launched, open access and peer-reviewed journal that dedicates to publish the release of genetically modified organisms (GMOs), GMO safety,     

In vivo studies on the metabolism of the monoterpene pulegone in humans using the metabolism of ingestion-correlated amounts (MICA) approach: explanation for the toxicity differences between (S)-(-)- and (R)-(+)-pulegone

The major in vivo metabolites of (S)-(-)-pulegone in humans using a metabolism of ingestion-correlated amounts (MICA) experiment were newly identified as 2-(2-hydroxy-1-methylethyl)-5-methylcyclohexanone (8-hydroxymenthone, M1), 3-hydroxy-3-methyl-6-(1-methylethyl)cyclohexanone (1-hydroxymenthone, M2), 3-methyl-6-(1-methylethyl)cyclohexanol (menthol), and E-2-(2-hydroxy-1-methylethylidene)-5-methylcyclohexanone (10-hydroxypulegone, M4) on the basis of mass spectrometric analysis in combination with syntheses and NMR experiments. Minor metabolites were be identified as 3-methyl-6-(1-methylethyl)-2-cyclohexenone (piperitone, M5) and alpha,alpha,4-trimethyl-1-cyclohexene-1-methanol (3-p-menthen-8-ol, M6). Menthofuran was not a major metabolite of pulegone and is most probably an artifact formed during workup from known (M4) and/or unknown precursors. The differences in toxicity between (S)-(-)- and (R)-(+)-pulegone can be explained by the strongly diminished ability for enzymatic reduction of the double bond in (R)-(+)-pulegone. This might lead to further oxidative metabolism of 10-hydroxypulegone (M4) and the formation of further currently undetected metabolites that might account for the observed hepatotoxic and pneumotoxic activity in humans.