Chemistry Institute, Federal University of Rio de Janeiro, CT, Ilha do Fundão, Rio de Janeiro 21941-909, RJ, Brazil.
Molecules. 2013 Jan 16;18(1):1128-37. doi: 10.3390/molecules18011128.
Croton cajucara is a shrub native to the Amazon region locally known as "sacaca". Two morphotypes are known: white and red "sacaca". The essential oils (EO) obtained by hydrodistillation from leaves of the red morphotype were, in general, rich in 7-hydroxycalamenene (28.4%-37.5%). The effectiveness of these EO regarding the antimicrobial activity against pathogenic microorganisms was initially investigated by the drop test method, showing significant inhibition zones. Among the microorganisms tested, the essential oils rich in 7-hydroxycalamenene were more effective against methicillin resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Mycobacterium tuberculosis, M. smegmatis, Mucor circinelloides and Rhizopus oryzae. The minimum inhibitory concentrations (MIC) of the oils were determined using the broth dilution assay. It was possible to observe that 7-hydroxycalamenene-rich oils presented high antimicrobial activity, with MIC of 4.76 × 10⁻³ μg/mL for MRSA, 4.88 μg/mL for M. tuberculosis, 39.06 μg/mL for M. smegmatis, and 0.152 μg/mL for R. oryzae and 3.63 × 10⁻⁸ μg/mL for M. circinelloides. The antioxidant activity of this EO suggests that 7-hydroxycalamenene provides more antioxidant activity according with EC(50) less than 63.59 μg/mL. Considering the bioactive potential of EOs and 7-hydroxycalamenene could be of great interest for development of antimicrobials for therapeutic use in treatment of bacterial and fungal infections in humans and/or veterinary practice.
克罗顿 Cajucara 是一种原产于亚马逊地区的灌木，当地称为“sacaca”。已知有两种形态类型：白色和红色“sacaca”。通过水蒸气蒸馏从红色形态型的叶子中获得的精油（EO）通常富含 7-羟基卡兰烯（28.4%-37.5%）。这些 EO 对致病性微生物的抗菌活性的有效性最初通过滴注测试方法进行了研究，显示出明显的抑制区。在所测试的微生物中，富含 7-羟基卡兰烯的精油对耐甲氧西林金黄色葡萄球菌（MRSA）、粪肠球菌、结核分枝杆菌、耻垢分枝杆菌、米根霉和米曲霉的抑制作用更为有效。使用肉汤稀释法测定油的最小抑菌浓度（MIC）。可以观察到富含 7-羟基卡兰烯的油具有高抗菌活性，MRSA 的 MIC 为 4.76×10⁻³μg/mL，结核分枝杆菌的 MIC 为 4.88μg/mL，耻垢分枝杆菌的 MIC 为 39.06μg/mL，米曲霉的 MIC 为 0.152μg/mL，米根霉的 MIC 为 3.63×10⁻⁸μg/mL。该 EO 的抗氧化活性表明，7-羟基卡兰烯根据 EC（50）小于 63.59μg/mL 提供更高的抗氧化活性。考虑到 EO 和 7-羟基卡兰烯的生物活性潜力，对于开发用于治疗人类和/或兽医实践中细菌和真菌感染的治疗性抗菌剂可能具有重要意义。
