Reconsidering Hydrosols as Main Products of Aromatic Plants Manufactory: The Lavandin (Lavandula × intermedia) Case Study in Tuscany

Abstract

The present work evaluates for the first time two Lavandin (Lavandula × intermedia Emeric ex Loisel.) aromatic waters obtained from different plant organs, the flowers and the stems. Both extracts were analysed by GC-MS, which indicates semi-quantitative differences between the major metabolites including linalool, 1,8-cineole, camphor, linalyl acetate and 4-terpineol. 1H-NMR and LC-MS investigation confirmed the presence of these compounds. Moreover, behavioural tests with the food insect pest Tribolium confusum (Coleoptera Tenebrionidae) showed a good repellency for both hydrosols extracts with RD50 values of 3.6 and 3.3 µL·cm−2 for the flowers and stems, respectively; at the higher concentrations, however, the hydrosol extract from the flowers is expected to be more effective than the one from the stems. The effect of the flowers and stems aromatic water of Lavandin on seed germination of Raphanus sativus was also evaluated. Results showed that seed germination was completely inhibited by flowers hydrolate, having a possible application as natural herbicide. The overall experience with these Lavandin extracts indicates the potential of improved hydrolates to become the main distillation products, rather than by-products, of the aromatic plants manufacturing; this stimulates further discussions about the potential positive impacts that such a shift could have in the context of ecopharmacognosy.

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens

“…To confirm the Probit results (and in the meantime to provide a more synthetic output of the results), bioassays data were also processed by one-way between-groups univariate analysis of covariance (ANCOVA), with the EOs as a fixed factor and the dose/concentration as a covariate to control its effects in the model. The mean response for each factor (EOs), adjusted for the dose/concentration, was reported as estimated marginal (EM) means, and significant differences among them were determined by post hoc comparisons using Bonferroni corrections for multiple comparisons [ 20 , 21 , 53 , 54 ]. The EOs protective effect data were processed by the Kruskal–Wallis test with the OAI as a factor.…”

Antioxidant and Acetylcholinesterase Inhibition Capacity of Hyrosols From Lamiaceae Plants for Biopesticide Use. The Role of Phenolic Compounds

“…The main volatile compounds identi ed in the ISO standard and analysed in lavender essential oils were linalyl acetate (36.55%), linalool (31.17%), cis-β-ocimene (3.33%), lavandulyl acetate (1.86%), 1-octen-3-yl acetate (1.64%), 1,8cineole (1.46%) and camphor (0.53%) [37]. Comparison of distillation extracts from Italian L. intermedia showed that the major compound of the essential oil, linalyl acetate, was changed with linalool and linalool oxide in the hydrosol of the same species, being completed by lower percentage of 1,8-cineole, camphor, geraniol and borneol [13]. Our results were consistent with previous studies, indicating a broad distribution of several volatile components in lavender hydrosol prepared by steam distillation, with linalool and derivatives, α-terpineol and terpinen-4-ol, and coumarin as main compounds.…”

“…On the other hand, some of the volatile compounds demonstrated pesticide activity. Thus, the cyclic monoterpene 1,8-cineole present in rosemary hydrosol and camphor detected in high proportion in sage and rosemary hydrosols, had unpleasant odour and were classi ed as insect repellents and antifeedants [13,56]. In turn, terpinen-4-ol, a monoterpene alcohol, and linalool, an acyclic terpene alcohol, detected in lavender hydrosol, were previously reported to have herbicide potential, acting as phytotoxic agents for weed germination inhibition [13].…”

“…Hydrosols containing phenolics, saponins and terpenes were previously tested for insecticide, toxicity and repellent activity against aphids, mites and beetles. Thus, sweet basil (Ocimum basilicum) and fringed rue (Ruta chalepensis) hydrosols had adverse effect on the reproduction and survival of Aphis gossypii aphid and Tetranychus urticae mite in leaf disk treatment [12], while lavender (Lavandula intermedia) hydrosol had similar activity to a synthetic repellent, but at 10 3 times higher concentrations on Tribolium confusum beetle [13]. Hydrosols of two mint species (Mentha pulegium, Mentha suaveolens) showed a dose-dependent mortality of Toxoptera aurantii aphid in Petri biotests [14], while hydrosols of marjoram (Origanum majorana) and pennyroyal (Mentha pulegium) caused mortality of Myzus persicae aphids after 24 h of leaf disk exposure [15].…”

Toward a New Future for Essential Oils

“…Although more perishable than EOs, these natural compounds have fair antimicrobial activity, are generally safe, and do not need to be diluted in a vehicle before use. These characteristics make them suitable not only for human and veterinary medicine (for both topical applications and oral administration), but also for other applications such as environmental, entomological, and agronomic applications [ 14 , 15 , 16 ].…”