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Biotransformation of Monoterpenoids by Microorganisms, Insects, and Mammals
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Yoshiaki Noma, Yoshinori Asakawa
Limonene is the most widely distributed terpene in nature after α-pinene (4) (Krasnobajew, 1984). (4R)-(+)-Limonene (68) is present in citrus peel oils at a concentration of over 90%; a low concentration of the (4S)-(−)-limonene (68′) is found in oils from the Mentha species and conifers (Bauer et al., 1990). The first microbial biotransformation on limonene was carried out by using a soil Pseudomonad. The microorganism was isolated by the enrichment culture technique on limonene as the sole source of carbon (Dhavalikar and Bhattacharyya, 1966). The microorganism was also capable of growing on α-pinene (4), β-pinene (1), 1-p-menthene (62), and p-cymene (178). The optimal level of limonene for growth was 0.3%–0.6% (v/v) although no toxicity was observed at 2% levels. Fermentation of limonene (68) by this bacterium in a mineral salt medium resulted in the formation of a large number of neutral and acidic products such as dihydrocarvone (64), carvone (61), carveol (60), 8-p-menthene-1,2-cis-diol (65b), 8-p-menthen-1-ol-2-one (66), 8-p-menthene-1,2-trans-diol (65a), and 1-p-menthene-6,9-diol (62). Perillic acid (69), β-isopropenyl pimaric acid (72), 2-hydroxy-8-p-menthen-7-oic acid (70), and 4,9-dihydroxy-1-p-menthen-7-oic acid (73) were isolated and identified as acidic compounds. Based on these data, three distinct pathways for the catabolism of limonene (68) by the soil Pseudomonad were proposed by Dhavalikar et al. (1966), involving allylic oxygenation (pathway 1), oxygenation of the 1,2-double bond (pathway 2), and progressive oxidation of the 7-methyl group to perillic acid (82) (pathway 3) (Figure 22.27) (Krasnobajew, 1984). Pathway 2 yields (+)-dihydrocarvone (101) via intermediate limonene epoxide (69) and 8-p-menthen-1-ol-2- one (72) as oxidation product of limonene-1,2-diol (71). The third and main pathway leads to perillyl alcohol (74), perillaldehyde (78), perillic acid (82), constituents of various essential oils and used in the flavor and fragrance industry (Fenaroli, 1975), 2-oxo-8-p-menthen-7-oic acid (85), β-isopropenyl pimaric acid (86), and 4,9-dihydroxy-1-p-menthene-7-oic acid (83).
Promising anti-Helicobacter pylori and anti-inflammatory metabolites from unused parts of Phoenix dactylifera CV ‘Zaghloul’: in vitro and in silico study
Published in Pharmaceutical Biology, 2023
Nada Elhefni, Sherif S. Ebada, Marwa M. Abdel-Aziz, El-Sayed M. Marwan, Saleh El-Sharkawy, Mona El-Neketi
A new sesquiterpene lactone derivative (1) was isolated from date palm tree waste along with ten known compounds (Figure 1), namely, pimaric acid (2) (Dang et al. 2005), vaginatin (3) (Yang et al. 2008), syringaresinol (4) (Malee 2011), chrysoeriol (5) (Bashyal et al. 2019), apigenin (6) (Alwahsh et al. 2015), luteolin (7) (Park et al. 2011), diosmetin-7-O-β-d-glucopyranoside (8) (Lee et al. 2012), methylparaben (9) (Yoshioka et al. 2004), p-hydroxybenzoic acid (10) (Yoshioka et al. 2004) and methyl β-d-xylopyranoside (11) (McEwan et al. 1982).