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Abstract

Tuberose flower extracts were obtained by green technology of Supercritical carbon dioxide (SC-CO 2 ) extraction and solvent extractions (using n-hexane and petroleum ether of b.p. 60-80 °C). Antimicrobial activities of these extracts were tested in vitro against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Helicobacter pylori, Vibrio cholerae and Candida albicans. No activity was found against H. pylori and V. cholerae. Antimicrobial activities of the extracts were established by minimum inhibitory concentration (MIC) assays against the remaining test microorganisms. The SC-CO 2 and solvent extracts showed potency against all test microorganisms. SC-CO 2 extract obtained at 40 °C, 100 bar pressure, 135 min extraction time, and n-hexane extract showed most promising results, among all the extracts. However, considering the global need for green extracts for therapeutic applications, SC-CO 2 extraction is the recommended technique for extracting antimicrobials from tuberose flowers. The chemical constituents conferring antimicrobial potencies to the extracts were also identified by GC/MS analyses.

Effect of Supercritical Fluid Extraction Process on Chemical Composition of Polianthes tuberosa Flower Extracts

“…The main volatile compounds from tuberose flowers were found predominantly at lower pressure extraction (18 MPa), while common compounds in supercritical plant extracts, as terpenes, alcohols, and some fatty acids were found in almost all extracts at different extraction pressures. Similar behavior was reported by Ghosh et al [4] and Gomes et al [18].…”

“…Tuberose flowers yield extracts obtained at different pressure and temperature processes are shown in Table 1, and were different and higher than yields reported by Gosh et al [4], who reported a supercritical yield extraction of 0.5%. Yield extracts were even higher than those reported by Rakthaworn et al [2], who evaluated different extraction methods and reported yields of tuberose flowers extracts obtained by cold palm wax enfleurage, hot palm oil enfleurage, and solvent extraction with hexane and petroleum ether, obtaining yields of 0.3137%, 6.5808%, 0.0279%, and 0.0182% respectively.…”

“…Tuberose flowers weighing 100 g were placed into the extraction vessel, and the effects of three pressure levels, 18, 28, and 38 megapascals (MPa) and three temperature levels, 313, 323, and 333 K were evaluated for extraction yield and chemical composition of the extract. A constant flow of 10 g/min CO 2 (medical grade, INFRA TM , Guadalajara, México) was established with bottom extraction vessel feeding, total extraction time was 3 h [4,12,20]. Extracts obtained in collector vessel were kept in amber flasks and stored at 253 K until gas chromatography analysis, and a diagram of the process is displayed in Figure 1.…”

“…Due to its odor, extracts from tuberose flowers have high value in the perfume industry [2]. Furthermore, there are reports mentioning that extracts from tuberose flowers contain bioactive compounds which show antimicrobial or insecticidal activity [3,4], giving a special interest value to tuberose extracts.…”

“…Moreover, the quality of supercritical extracts has been compared to enfleurage [2], and because of its benefits, SFE also has been used for recovery of volatile compounds from different flowers, such as lavender, jasmine, and geranium [17][18][19]. SFE also has been used for extraction of tuberose flowers; studies report low yield extracts, and few chemical compounds have been identified in extracts [2,4,20].…”