Anti-Zygomycetes activity of 7-hydroxycalamenene isolated from Croton cajucara

The leaves and bark from Croton cajucara Benth. (family Euphorbiaceae), a shrub from the Amazon, have been used locally used in folk medicine to treat diabetes, malaria, gastrointestinal and liver disorders [1]. The essential oil from the leaves is rich in linalool [2] and presented antileishmanial and antimicrobial activities [3,4]. A chemotype of this species was found, with an essential oil rich in 7-hydroxycalamenene [5]. This substance is reported to have antifungal activity against Botrytis cinerea, Cladosporium cucumerinum, Phythophthora infestans, Pyricularia oryzae and Septoria tritici [6]. During our studies with C. cajucara oil, we isolated 7-hydroxycalamente by silicagel column chromatography followed by preparative TLC. The pure compound (+98% by GC) was tested against some zygomycetes. A minimum inhibitory concentration (MIC) of 9.76µg/mL was found to Absidia corymbifera, Cunninghamella elegans and Mucor circinelloides f. circinelloides, while for Rhizopus microsporus and Rhizopus oryzae the MIC was 19.53µg/mL. The reference drug used, amphotericin B, presented a MIC of 43.9µg/mL for C. elegans and M. circinelloides, and 0.3µg/mL for the other species tested.

From these data, it was observed 7-hydroxycalamenene is a compound with good activity against zygomycetes.

Keywords: Zygomycetes, Croton cajucara, essential oil, antifungal activity

Acknowledgement: CAPES, FAPERJ.

References: 1. Maciel MAM et al. (2000)J Ethnopharmacol 70: 41–45.

2. Lopes D et al. (2000)J Essent Oil Res 12: 705–708.

3. Rosa MSCS et al. (2003) Antimicrob Agents Chemother 47: 1895–1901.

4. Alviano WS et al. (2005) Oral Microbiol Immunol 20: 101–105.

5. Pereira AQ et al. (2010)J Essent Oil Res 23: 20–23.

6. Scher JM et al. (2004) Phytochemistry 65: 2583–2588.