Microbial transformation of matricaria recutita L. essential oil and its components

The commercially available chamomile essential oil of pharmacopoeial quality was used after analytical verification by GC/MS and GC/FID where the main components were α-bisabolol oxides A (47.7%) and B (6.2%), (E)-β-farnesene (21.5%), α-bisabolone oxide A (5.7%), chamazulene (4.1%), and α-bisabolol (2.1%), respectively. In this thesis, it was aimed to investigate the biotransformation potential of chamomile essential oil and its components α-bisabolol, bisabolol oxides, farnesene, and chamazulene using 22 different microorganisms. In addition to the utilization of chamomile essential oil, the bisabolol oxides, chamazulene were isolated from the essential oil; whereas α-bisabolol and a mixture of farnesene isomers were obtained commercially, which were also used in the biotransformation studies. The metabolite of α-bisabolol was converted in high amount (94%) by Penicillium neocrassum, which was purified, and elucidated by chromatographic-spectroscopic techniques as new compound 2-(5-methyl-5-(6-methyl-7-oxabicyclo[4.1.0]heptan-3-yl)tetrahydrofuran-2-yl)propan-2-ol was named as "bisafuranol" for the first time as a new natural product. Among the five metabolites produced by microbial transformation of α-bisabolol, two were identified as α-bisabolol oxide A, and three as α-bisabolol oxide B. From the mixture of farnesene isomers, catalyzed by microorganisms, α-bisabolol oxide B, α-bisabolone oxide A, and two other metabolites were identified as α-bisabolol oxide A. In addition, in vitro antimicrobial (microdilution method), antioxidant (DPPH radical scavenging) effects of obtained biotransformation metabolite mixtures were evaluated for their bioactivities by cyclooxygenase-1 (COX-1), 5-lipoxygenase (5-LOX) enzyme inhibition experiments using micro-UV-spectrophometric methods, comparatively with substrates, where in silico toxicity was also considered. According to the toxicity prediction results, the new compound "bisafuranol" was found as orally non-toxic, which can be classified as partially safe.