Chemical composition ofHibiscus tiliaceus L. flowers: A study of extraction methods

Abstract

The objective of this work was to carry out a comparative study of conventional extraction methods (maceration and Soxhlet) versus sonication in the case of the flowers of Hibiscus tiliaceus, collected at the Santa Catarina swamps (in the south of Brazil), using three solvents with different degrees of polarity. All extracts were analyzed by GC/MSD. For all the extraction procedures used, the initial extraction was performed with hexane with the aim of completely removing non‐polar compounds (mainly hydrocarbons). This procedure will ensure that the compounds of real interest, i. e., those possessing pharmacological properties, can be better characterized. Variation of solvent type is found to have a much greater effect than variation of the extraction method. The total analysis time and the total amount of solvent are clearly reduced on use of the best method, i. e. sonication. The best sonication results were obtained with an extraction time of 160 minutes using methanol as extraction solvent. The solvent used determines the nature of the compounds extracted. Polar compounds are satisfactorily extracted by using highly polar solvents. Among the compounds identified, saturated hydrocarbons from 25 to 33 carbon atoms, esters, and carboxylic acids of high molecular weight, as well as some steroid structures are highlighted.

Ultrasonic Extracts of Morinda citrifolia L.: Characterization of Volatile Compounds by Gas Chromatography-Mass Spectrometry

“…In general, ethanol was considered a better solvent, yielding higher amount of extract than hexane, both for leaves and fruits, as already found in the literature. 8 According to Sticher,22 using non-polar solvents (such as hexane), more lipophilic compounds are obtained, while polar solvents as alcohols provide an extract with a broad spectrum of polar and nonpolar substances, increasing the yield of extraction. The yields for the leaves extracts were slightly higher than those obtained for the fruits, considering both solvents.…”

“…9 UAE is one of the most efficient extraction techniques due to its intense interaction between solid (plant) and liquid (solvent) phases. [8][9][10][11] Sonication has some advantages over other extraction techniques such as the low cost, simplicity, efficiency, reproducibility and the applicability for a high range of samples. 8,[10][11][12] The implosion of bubbles generated by cavitation releases heat and increases turbulence on the liquid, causing the disruption of the plant cells, allowing the diffusion of the solvent into the matrix.…”

“…5 Many methodologies have been developed worldwide for characterizing different natural compounds aiming to identify and quantify the bioactive ones, indicating their application in food or phytomedicine. [6][7][8] The amount and quality of extracts are strongly associated to the extraction technique applied. Sonication, or ultrasound-assisted extraction (UAE), is a physical procedure that uses the energy of ultrasound waves for producing variations on the liquid pressure, generating the cavitation process and promoting the extraction.…”

“…13,14 The extracts are normally analyzed by gas chromatography-mass spectrometry (GC-MS). 8,15 Among the phytotherapeutic effects of noni, it is possible to highlight the anti-inflammatory, analgesic and diuretic activities. In addition, noni contains vitamins C and E in amounts similar to papaya, acerola, cashew and pineapple.…”

Preliminary study of the influence of CO2 extraction conditions on the ester, aldehyde, ketone and hydrocarbon content of grape bagasses from jam production

“…This technique is also widely employed in the chemical characterization of natural products (Melecchi et al, 2002;Zeng and Khan, 1995;Mossi et al, 2004).…”