The microbial transformation of (À)-Ambrox ¾ (1), a perfumery sesquiterpene, by a number of fungi, by means of standard two-stage-fermentation technique, afforded ambrox-1a-ol (2), ambrox-1a,11a-diol (3), ambrox-1a,6a-diol (4), ambrox-1a,6a,11a-triol (5), ambrox-3-one (6), ambrox-3b-ol (7), ambrox-3b,6b-diol (8), 13,14,15,16-tetranorlabdane-3,8,12-triol (9), and sclareolide (10) (Schemes 1 and 2). Further incubation of compound 10 with Cunninghamella elegans afforded 3-oxosclareolide (11), 3b-hydroxysclareolide (12), 2a-hydroxysclareolide (13), 2a,3b-dihydroxysclareolide (14), 1a,3b-dihydroxysclareolide (15), and 3b-hydroxy-8-episclareolide (16) (Scheme 3). Metabolites 2 ± 5, 12, 13, and 16 were found to be new compounds. The major transformations include a reaction path involving hydroxylation, ether-bond cleavage and inversion of configuration. Metabolites 11 ± 16 of sclareolide showed significant phytotoxicity ( Table 1). The structures of the metabolites were characterized on the basis of spectroscopic techniques.Introduction. ± In continuation of our studies on biotransformation of bioactive natural and synthetic compounds [1 ± 11], we have recently investigated the biotransformation of two sesquiterpenes, (À)-Ambrox ¾ (1) and ()-sclareolide (10), with various fungal strains. Ambergris, a metabolite of the sperm whale, is one of the mostvaluable animal perfumes, ranking with civet and musk [12] [13]. Ambrein is the major constituent of the ambergris. During exposure in the sea for many years, ambrein is oxidatively decomposed by the action of sea water, air, and sunlight to yield some other odorous compounds [14]. In these compounds, (À)-Ambrox ¾ (1) has a very strong amber-like odor.Fermentation of (À)-Ambrox ¾ (1) with Fusarium lini (NRRL 68751) afforded the new mono-, di-, and trihydroxylated metabolites 2 ± 5, as a result of enantioselective ahydroxylations at C(1), C(6), and C(11), while incubation of compound 1 with Rhizopus stolonifer (ATCC 10404) yielded metabolites 6 ± 8 and ether-cleaved product 9. The ether cleavage through biotransformation is a rare observation. Fermentation of compound 1 with Curvularia lunata (NRRL 2178) yielded metabolites 6 and 7, while its biotransformation with Cunninghamella elegans (NRRL 1392) afforded compounds 6, 7, and ()-sclareolide (10). Compounds 6 ± 10 have already been reported as metabolites of 1 by Cephalosporium aphidicola (wild type), Aspergillus niger (IFO 4049), Aspergillus cellulose (IFO 4040), and Botryatis cinerea (AHU 9424) [15 ± 19]. The oxygenated metabolites of compound 1 did not release any effective odor when compared to 1, except for the ether-cleaved product 9, which exhibited a strong sweet odor quit different from the amber-like odor.

The absolute from Zataria multiflora was explored for enzyme inhibition, insect repellent, and insecticidal activities. GC-MS of the absolute of fresh plant showed that thymol is the major constituent while carvacrol is the major constituent in the absolute of dried plant.