Abstract
The leaves and bark of Croton cajucara, a shrub from the Amazon region, have been used in
folk medicine to treat diabetes, malaria, and gastrointestinal and liver disorders.
The
essential oil from the leaves, rich in linalool, presented antileishmanial and antimicrobial
activities. A chemotype of this species was found with an essential oil rich in
7-hydroxycalamenene. During our studies of the C. cajucara essential oil, we isolated
7-hydroxycalamenene at > 98 % purity. The minimum inhibitory concentration of
7-hydroxycalamenene against Absidia cylindrospora, Cunninghamella elegans, Mucor
circinelloides, Mucor circinelloides f. circinelloides, Mucor mucedo, Mucor plumbeus,
Mucor
ramosissimus, Rhizopus microsporus, Rhizopus oryzae, and Syncephalastrum
racemosum ranged from 19.53 to 2500 µg/mL. The reference drug used, amphotericin B,
presented a minimum inhibitory concentration ranging from 0.085 µg/mL to 43.87 µg/mL.
7-Hydroxycalamenene also altered spore differentiation and total lipid content. Ultrastructural
analysis by transmission electron microscopy showed significant alterations in the
cellular
structure of R. oryzae.
Key words
7-Hydroxycalamenene -
Rhizopus oryzae
- zygomycetes -
Croton cajucara
- Euphorbiaceae - essential oil