Constituents of the Essential Oil ofSuregada zanzibariensisLeaves are Repellent to the Mosquito,Anopheles gambiaes.s.

Abstract

In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents.

Potential Use of an Essential Oil From the Flower of Swertia densifolia as a Repellent for Apis florea (Hymenoptera: Apidae)

“…c Average number of bees visiting the test formulation counted during a period of 10 min (n ¼ 7). female adult mosquitoes (Innocent et al 2010). Another study of odorant receptor modulation in insect repellents also found a synergistic effect among the constituents of repellent formulation (Bohbot and Dickens 2012).…”

Chemical compositions and mosquito repellency of essential oils from <i>Artabotrys hexapetalus</i> and <i>Artabotrys rupestris</i>

“…The percentage protective efficacy (PE) was estimated by Abbot Formula as: P.E = (ZC -ZT) / ZT × 100, where ZC and ZT are the mean numbers of mosquito that landed on control and treated arms, respectively (Innocent et al, 2010;SAS Institute, 2000). The data were subjected to analysis of variance (ANOVA) and the mean percentage protection compared using Students-NewmanKeuls (SNK) of SAS package.…”

“…Fractional hydrodistillation was carried out to extract oils from the plant parts using a Clevenger-type water steam distillation apparatus and the process continued until all the essential oils were extracted from the plant materials. The extraction procedure was carried out as previously described by Innocent et al (2010) with modifications involving collections of fractions. The oil was collected at interval of 50 min in order to get three different fractions.…”

“…Mosquito repellency assay procedure as described by Innocent et al (2010) was adopted. The mosquito repellency assays were carried out at Amani Research Centre of the National Institute for Medical Research (NIMR) Muheza District, Tanga Region, in Tanzania.…”

Aleurites moluccana (L.) Willd.: características gerais, farmacológicas e fitoquímicas

“…6 Outra é na medicina popular, sendo as Euphorbiaceae aplicadas em diversas enfermidades: diabetes, úlceras, diarreia, malária, febre, problemas estomacais, inflamações do fígado, rins e vesícula, câncer, colesterol, além do uso como cicatrizante, tônica, sedativa e ansiolítica. 11,12 Entretanto, apesar das atividades biológicas descritas, a literatura também alerta para a presença de metabólitos secundários com potencial tóxico da família, sendo necessários estudos que garantam a sua segurança toxicológica. As proteínas obtidas das sementes de Croton tiglium demonstraram potencial tóxico e atividade pró-inflamatória, 8 e o extrato aquoso de sementes de Aleurites moluccana apresentou toxicidade oral aguda em ensaios in vivo.…”