Biotransformation of androst-4-ene-3,17-dione and nandrolone decanoate by genera of Aspergillus and Fusarium.

The ability of five fungal species belonging to two genera of Aspergillus and Fusarium has been examined in the microbial transformation of androst-4-ene-3, 17-dione (AD). Furthermore, the biotransformation of nandrolone decanoate (2) by F. fujikuroi has been studied. AD (1) was converted by cultures of Aspergillus sp. PTCC 5266 to form 11α-hydroxy-AD (3) as the only product, with a yield of 86% in 3 days. Moreover, two hydroxylated metabolites 11α-hydroxy-AD (3, 65%) and 7ß-hydroxy-AD (4; 18%) were isolated in biotransformation of AD by A. nidulans. On the other hand, it was metabolized by F. oxysporum to produce 14α-hydroxy-AD (5; 38%) and testosterone (6; 12%). Microbial transformation of AD by F. solani led to the production of 11α-hydroxy-AD (3; 54%) and testosterone (6; 14%). AD was reduced at the 17-position by F. fujikuroi to produce testosterone in the yield of 42%. Finally, nandrolone decanoate was transformed by F. fujikuroi via hydrolysis and oxidation at the 17-position to produce two metabolites namely 17ß-hydroxyestr-4-en-3-one (7, 25.4%) and estr-4-en-3,17-dione (8, 33%), respectively. The all metabolites were purified and subsequently identified based on their spectra data analysis and comparing them to the literature data.

The 11α-hydroxylation of medroxyprogesterone acetate by Absidia griseolla var. igachii and Acremonium chrysogenum.

Medroxyprogesterone acetate (MPA) (1) has been transformed by two filamentous fungi, including Absidia griseolla var. igachii and Acremonium chrysogenum, into 11α-hydroxy-medroxyprogesterone acetate (2) as the major metabolite. The structure of the product was identified by different spectroscopic methods (1D- and 2D-NMR, EI-MS, and elemental analysis). Moreover, a time course study determined by HPLC showed 63% and 48% yields for the metabolite by using the two mentioned fungi, respectively. Finally, the effect of the temperature and concentration of the substrate were investigated, which the optimal fermentation conditions were found to be 25 °C with a substrate concentration of 0.1% (w/v). This study reports for the first time the production of 11α-hydroxy-medroxyprogesterone acetate as a fungal biotransformation product.

Immobilisation of lipase on the surface of magnetic nanoparticles and non-porous glass beads for regioselective acetylation of prednisolone.

Magnetic nanoparticles (MNPs) were prepared by co-precipitation of Fe+3/Fe+2 (2:1; molar ratio) with a mean size of 40 ± 5 nm. Scanning electron microscopy, dynamic light scattering, X-ray diffraction, vibrating sample magnetometer and thermogravimetric analysis were used to characterise the MNPs. The MNPs and also hydroxylated nonporous glass beads were similarly functionalised with the aid of glutaraldehyde to be cross-linked to lipase originated from Thermomyces lanuginosus (TLL). The yield and efficiency for immobilised lipase on the MNPs were calculated as 72 ± 2.4 and 63 ± 3.5%, whereas a yield and efficiency of 60 ± 2.1 and 55 ± 4.1%, respectively, were measured for the corresponding parameters of the immobilised enzyme on the glass beads. When the immobilised TLL was compared with its free form, Michaelis-Menten kinetics indicated an insignificant change in the Michaelis constant (Km) and a drastic decrease in the maximum substrate conversion rate (Vmax). The immobilised TLL and six other commercial lipases were then checked for regioselective acetylation of prednisolone. The highest and lowest yields of the product were observed for Novozym 435 and immobilised TLL on the glass beads, respectively. Immobilised TLL retained its bioacetylation activity of prednisolone in five successive catalytic processes.

Meldrum's acid catalyzed reaction of tetracyanoethylene and aldehydes in water: a novel approach to arylidenemalononitrile.

Meldrum's acid catalyzed the reaction of tetracyanoethylene with aromatic, heteroaromatic, and conjugated aldehydes led to arylidenemalononitrile in water in good yields at 80 degrees C. The work-up of reactions is very simple and the crude products are sufficiently pure to be used without further purification. The procedure provides an alternative method for the synthesis of arylidenemalononitrile.

A novel method for the synthesis of substituted 3,4-dihydrocoumarin derivatives via isocyanide-based three-component reaction.

A new one-pot procedure for the efficient synthesis of novel 3,4-dihydrocoumarin derivatives using commercially available substituted 2-hydroxybenzaldehydes, Meldrum's acid, and isocyanides by a three-component condensation reaction in dichloromethane at room temperature without using any catalysts and activation was developed.