A tetracosatetraene as larvicidal compound isolated from <i>Alpinia katsumadai</i>

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P> <I>Plutella xylostella</I> and <I>Mythimna separata</I> are destructive insect pests causing damages to agricultural products. In this study, a larvicidal compound was identified by bioassay-guided isolation of methanol extracts of <I>Alpinia katsumadai</I> Hayata, a plant belonging to the Zingiberaceae, against <I>P. xylostella</I> and <I>M. separata</I> larvae. Because many insects, including <I>P. xylostella</I> and <I>M. separate</I> larvae, cannot synthesize sterols, they use phytosterols by converting them to the sterols necessary for hormonopoiesis, and resulting normal development, growth and reproduction. Results of our oil droplet formation test showed that compound 1 inhibited foam cell formation in ox-LDL treated THP-1 cells, suggesting that this compound may be inhibiting the sterol transport in insects. The compound 1 with larvicidal activity was elucidated by spectroscopic analysis (<SUP>1</SUP>H NMR, <SUP>13</SUP>C NMR, and ESI–MS) as 2,3,22,23-tertrahydroxy-2,6,10,15,19,23-hexamethyl-6,10,14,18- tetracosatetraene. The 50% lethal concentration (LC<SUB>50</SUB>) values of compound 1 were 2μg/mL and 16.9μg/mL, respectively, against <I>P. xylostella</I> and <I>M. separata</I> larvae.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The novel larvicidal compound was identified from <I>Alpinia katsumadai</I>. </LI> <LI> The active compound was isolated by bioassay-guidance with some chromatography. </LI> <LI> The active compound was elucidated by spectroscopic analysis with <SUP>1</SUP>H NMR, <SUP>13</SUP>C NMR, and ESI–MS. </LI> <LI> The active compound was screening by foam cell formation test with THP-1 cells. </LI> <LI> The active compound has larvicidal effect against <I>Plutella xylostella</I> L. and <I>Mythimna separate</I>. </LI> </UL> </P>