Structure Elucidation and Antibacterial Activity of New Fungal Metabolites of Sclareol

Abstract

The transformation of the antibacterial diterpene sclareol (1) by two different fungal strains was investigated (Scheme). In the presence of Rhizopus stolonifer, (3beta)-3-hydroxysclareol (2), 18-hydroxysclareol (3), (6alpha)-6,18-dihydroxysclareol (4), and (11S)-11,18-dihydroxysclareol (5) were formed. Fermentation of 1 with Fusarium lini afforded (1beta)-1-hydroxysclareol (6) and (12S)-12-hydroxysclareol (7). Compounds 4-7 were identified as new compounds, and some of them were active against Bacillus subtilis (Table 3).

Biotransformation of labdane and halimane diterpenoids by two filamentous fungi strains

“…Oxidation of substrate 1 at C-2 to provide 3 is probably favoured because these hydrogens are allylic to 1,10-double bond. Previously microbial transformations of diterpenoid substrates performed by Fusarium species encompasses conversion of dehydroabietic acid into its 1 β -hydroxy derivative by F. oxysporum [ 14 ], modification of sclareol with F. lini leading to 1 β -hydroxy and (12 S )-12-hydroxysclareol derivatives [ 16 ], and oxidation of cupressic acid by F. graminearum to produce four metabolites, including 3 β -hydroxy and 7 α -hydroxy analogues [ 17 ]. Sequential oxidations at position C-2 from diterpenoid substrate to alcohol and then oxo derivatives have been found to occur only with another fungus, Mucor plumbeus [ 18 ].…”

Low sclareol by‐product of clary sage concrete: chemical analysis of a waste product of the perfume industry

“…Further LSB studies led to the identification of several minor triterpenic compounds listed in Figure 3 and Table 1, such as 3-oxo-oleanolic acid (10), 2a,3a-dihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (4), taraxasterol acetate (11), and a-amyrin acetate (12). [13,27] The biosynthetic origin of 3-hydroxysclareol (1) and 3-oxosclareol (2) was investigated by analysing different industrially made concretes and freshly harvested S. sclarea concretes. Compounds 4 and 12 were only described in Salvia carduacea and Salvia cyanyscens, respectively.…”

Biotransformation of 11-ketoprogesterone by Filamentous Fungus, <i>Fusarium lini</i>

“…In continuation of the studies on biotransformation of bioactive compounds [8][9][10][11], fermentation of 1 by various fungal strains, resulted in synthesis of transformed analogues 2-11. These metabolites were unambiguously identified as pregna-1,4-diene-3,11,20-trione (2), androsta-1,4-diene-3,11,17-trione (3), 17β-hydroxy-androsta-1,4-diene-3,11-dione (4), 15α,17β-dihydroxy-androsta-1,4-diene-3,11-dione-17-acetate (5), 15α-hydroxy-pregna-1,4-diene-3,11,20-trione (6), 6β,15α-dihydroxy-pregna-1,4-diene-3,11,20-trione (7), 15α,17β-dihydroxy-androsta-1,4-diene-3,11-dione (8), 16α,17β-dihydroxy-androsta-1,4-diene-3,11-dione (9), 15α, 20R-dihydroxy-pregna-1,4-diene-3,11-dione (10), 15α, 20S-dihydroxy-pregna-1,4-diene-3,11-dione (11).…”

“…These metabolites were unambiguously identified as pregna-1,4-diene-3,11,20-trione (2), androsta-1,4-diene-3,11,17-trione (3), 17β-hydroxy-androsta-1,4-diene-3,11-dione (4), 15α,17β-dihydroxy-androsta-1,4-diene-3,11-dione-17-acetate (5), 15α-hydroxy-pregna-1,4-diene-3,11,20-trione (6), 6β,15α-dihydroxy-pregna-1,4-diene-3,11,20-trione (7), 15α,17β-dihydroxy-androsta-1,4-diene-3,11-dione (8), 16α,17β-dihydroxy-androsta-1,4-diene-3,11-dione (9), 15α, 20R-dihydroxy-pregna-1,4-diene-3,11-dione (10), 15α, 20S-dihydroxy-pregna-1,4-diene-3,11-dione (11). These include three known (2-4) and seven new polar metabolites (5)(6)(7)(8)(9)(10)(11). The structures of these metabolites were determined by spectroscopic studies and comparison with the spectral data of the substrate 1 and related other compounds.…”