Isolation of Volatile Compounds with Repellent Properties against (Diptera: Culicidae) Using CPC Technology.

The present work describes the use of Centrifugal Partition Chromatography (CPC) for the bio-guided isolation of repellent active volatile compounds from essential oils. Five essential oils (EOs) obtained from three and two species were initially analyzed by gas chromatography-mass spectrometry (GC/MS) and evaluated for their repellent properties against The essential oil from needles of (PPI) presented the higher activity, showing 82.4% repellency at a dose of 0.2 μL/cm. The above EO, together with the EO from the fruits of subsp. (JOX), were further analyzed by CPC using the biphasic system n-Heptane/ACN/BuOH in ratio 1.6/1.6/0.2 (). The analysis of PPI essential oil resulted in the recovery of (-)-limonene, guaiol and simple mixtures of (-)-limonene/-pheladrene, while the fractionation of JOX EO led to the recovery of -myrcene, germacrene-D, and mixtures of -pinene/-pinene (ratio 70/30) and -pinene/germacrene D (ratio 65/45). All isolated compounds and recovered mixtures were tested for their repellent activity. From them, (-)-limonene, guaiol, germacrene-D as well the mixtures of (-)-limonene/-pheladrene presented significant repellent activity (>97% repellency) against . The present methodology could be a valuable tool in the effort to develop potent mosquito repellents which are environmentally friendly.