Fungal transformation of isosteviol lactone and its biological evaluation for inhibiting the AP-1 transcription factor

Microorganisms in Chemistry of Terpenoids

“…Isosteviol lactone (CLXXXI) is biotransformed by A. niger BCRC 31130 to seven different hydroxylated diterpenoids, some of which inhibit the activator protein-1 transcription factor (Chou et al, 2009). Isostevic acid (CLXXXII) is hydroxylated by A. niger BCRC 32720 to eight metabolites with anti-inflammatory properties (Yang et al,2012): One of them, 2α-hydroxy-5α,10β,14β-triacetoxytaxa-4(20),11(12)diene, has the potential to prevent resistance to chemotherapeutic drugs in some tumor cells : Neoandrographolide (CXCIX), a diterpenoid from a Chinese traditional medicinal plant, is biotransformed by A. niger AS 3.739 to five products: 8 (17), 13-ent-labdadien-16,15-olid-19oic acid, 19-hydroxy-8(17),13-ent-labdadien-16,15-olide, 18hydroxy-8(17),13-ent-labdadien-16,15-olid-19-oic acid, 3αhydroxy-8(17),13-ent-labdadien-16,15-olid-19-oic acid, and 8β,19-dihydroxy-ent-labd-13-en-16,15-olide (Chen et al, 2007): (14), 15-trien-19-oic acid, 1α,6β,14β-trihydroxy-ent-pimara-7,15-dien-19-oic acid, and 1α,6β,7α,11α-tetrahydroxy-ent-pimara-8(14),15-dien-19-oic acid (Severiano et al, 2013):…”

The use of Aspergillus niger cultures for biotransformation of terpenoids

“…Another strain, A. niger IFO 4414, metabolizes isosteviol not only to 7␤-hydroxyisosteviol but also to 11␤-and 12␤-hydroxyisosteviol; all three of these metabolites have antitumor activity [78]. Isosteviol lactone (CLXII) is biotransformed by A. niger BCRC 31130 to seven different hydroxylated diterpenoids, some of which inhibit the activator protein-1 transcription factor [79]. Isostevic acid (CLXIII) is hydroxylated by A. niger BCRC 32720 to eight metabolites with anti-inflammatory properties [80]: Stemodin (CLXVII), a tetracyclic diterpenoid produced by the seaside twintip plant of Jamaica, is biotransformed in cultures of A. niger ATCC 9142 to 2␣,3␤,13-, 2␣,7␤,13-, and 2␣,13,16␤-trihydroxystemodane [67].…”

Anticariogenic Properties of ent-Pimarane Diterpenes Obtained by Microbial Transformation

“…According to several authors [ 10 , 11 ], drugs derived from natural products can serve not only as new drugs themselves, but also as lead compounds for chemical modifications that will furnish derivatives with better activity and pharmacokinetic properties, new mechanisms of action, and fewer adverse side effects [ 12 , 13 ]. Recently, it has been emphasized that these modifications can be performed by fungal biotransformation processes, which have presented various advantages over the use of conventional chemical reagents [ 14 , 15 , 16 ].…”