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Cyanobacterial toxins
Published in Ingrid Chorus, Martin Welker, Toxic Cyanobacteria in Water, 2021
The production of particular metabolites is highly clone-specific, and clones within a population can be described as chemotypes. A high chemotype diversity has been reported for species of Microcystis, Planktothrix, Dolichospermum (Anabaena) and Lyngbya, for example (Welker et al., 2007; Rohrlack et al., 2008; Leikoski et al., 2010; Engene et al., 2011; Haruštiaková & Welker, 2017; Le Manach et al., 2019; Tiam et al., 2019). Since individual cyanobacterial clones can produce multiple variants of multiple classes of metabolites, a multiclonal bloom of cyanobacteria can contain hundreds of bioactive metabolites (Welker et al., 2006; Rounge et al., 2010; Agha & Quesada, 2014). This diversity makes it difficult to relate an observed toxic effect that cannot be explained by the activity of known (and quantifiable) cyanotoxins to a particular compound in a specific sample. Hence, the key challenges for a comprehensive risk assessment of cyanopeptides are their structural diversity, the lack of analytical standards and complex requirements for their identification and quantification (Janssen, 2019).
Eco-friendly management strategies of insect pests: long-term performance of rosemary essential oil encapsulated into chitosan and gum Arabic
Published in International Journal of Environmental Health Research, 2023
Abir Soltani, Sarra Ncibi, Tasnim Djebbi, Amina Laabidi, Hela Mahmoudi, Jouda Mediouni-Ben Jemâa
Chromatographic analysis identified 23 compounds representing 98.35% of the total essential oil. 1,8-Cineole (39.67%), Camphor (18.04%), followed by borneol (10.51%) and α-Pinene (6.33%) were the major components. The results obtained in this study are consistent with findings reported by Bannour et al. (2006), who analyzed the chemical composition of essential oils from four Tunisian populations rosemary. They found that the oils were mainly composed of 1,8-cineole, camphor, α-pinene, and borneol although in varying proportions. Similarly, Napoli et al. (2010) described three chemotypes of rosemary essential oil: cineoliferum which had a high percentage of 1,8- cineole; camphoriferum characterized by significant amount of camphor (over 20%); and verbenoniferum, with more than 15% verbenone. This research showed that the chemotype was defined by 1,8-cineole/camphor. Identified compounds have been grouped into chemical classes (hydrocarbon monoterpenes, oxygenated monoterpenes, hydrocarbon sesquiterpenes, and other compounds) (Table 2). Recent study conducted by Abada et al. (2019) defined 1,8-cineole/α-pinene/camphor as the chemotype of rosemary essential oil collected from different localities in Tunisia. Similarly, Khalil et al. (2017), reported the chemical composition of rosemary essential oil collected from Hamada region in Tunisia, which consisted mainly of camphor (16.29%), 1,8-cineole (16,21%), bornyl acetate (14.54%), and borneol (6.02%). Another study conducted in Morocco found that camphor (31.6) and β-caryophyllene (18.5) were the major compounds in R. officinalis essential oil (Ainane et al. 2020). In this work, Monoterpenes presented the significant fraction of the oil (71.14% including 58.87% oxygenated Monoterpenes). Consistent with other research, the composition of rosemary essential oil is known to vary according to the chemotype of the plant, with common compounds including 1,8-cineole, camphor, α-pinene, β-caryophyllene, borneol, and verbenone (Chung et al. 2020).