Plant essential oils, alternative

ABSTRACT This study shows that, in spite of the great biological and cultural potential in Brazil, there is, even today, no phytomedicines originating from this flora, as an alternative to allopathic anxiolytics and hypnotics prescribed by psychiatry. Thirty-nine plants with potential anxiolytic effects and 28 hypnotics were indicated in the course of ethnopharmacological surveys carried out with Afro-Brazilians and/or Quilombolas, the Caboclo population (river-dwellers), and Indians in Brazil. Practically no pharmacological studies have been found in the scientific literature as evidence of their popular use. From the phytochemical point of view, it is of interest to observe that flavonoids, essential oils, phenolic acids, and alkaloids are the chemical constituents predominantly present in these species, both in those indicated as anxiolytic, and the hypnotic. 

Asa practical example of the significance of elevation in chemical processes, consider the steam extraction of essential oils. Low temperatures are preferred to extract oil from plants because of their susceptibility to degradation. Thus, an alternative to vacuum extraction would be to operate at higher elevation. 

NIR can also play an important role in phytoanalysis. There are some reports on the use of NIR for the quantitative analysis of water content, residual solvents of dry extracts, as well as for the analysis of constituents. It has been used in the analysis of polyphenols (wine, soy) and a quantitative NIR reflectance spectroscopy method was established for the determination of two major constituents of St John s wort (hyperforin and biapigenin) using HPLC as reference method. It was also successfully used for the rapid evaluation and quantitative analysis of essential oils using GC as reference method. It can be considered a rapid and highly effective alternative method to conventional quantitative analysis of plant extracts. 

Essential oils are secondary metabolites produced in the plants as volatile aromatic principles. They are colorless and rarely colored and soluble in organic solvents. It is fotmd in all part of the plants and is stored in epidermal cells, trichomes, secretory cells, canals, and cavities. They are extracted by the use of liquid carbon dioxide or microwaves, expression and mainly steam or hydrodistillation process. Due to their biological, nutritive, and pharmaceutical properties, they are more attractive alternatives to synthetic chemical products to protect the equilibrium. 

The societal claim for a friendly environmental use of pesticides today implicates to promote alternative solutions for a better and relevant using of chemicals. Because they have a broad spectrum of uses, essential oils (EOs) have many industrial applications. They are used now in plant protection and as biocide. They occupy a significant place among insect pest biocontrol agents (BCAs) and represent a consistent part within the market of botanicals used as alternative to chemicals. After phytochemical considerations, this chapter... 

Assnming that the global market of antibiotic growth stimulators was worth 237 million US dollars in its peak in 1996 (Greathead 2003), it is not difQcult to predict the implications related to the increasing interest in alternative fermentation modulators, including the whole plants, plant oils, plant extracts, essential oils or, finally, the very biologically active factors. 

---