Biocatalysis of ursolic acid by the fungus Gliocladium roseum CGMCC 3.3657 and resulting anti-HCV activity

Optimization of biotransformation processes of Camarosporium laburnicola to improve production yields of potent telomerase activators

BACKGROUND

Telomerase activators are promising agents for the healthy aging process and the treatment/prevention of short telomere-related and age-related diseases. The discovery of new telomerase activators and later optimizing their activities through chemical and biological transformations are crucial for the pharmaceutical sector. In our previous studies, several potent telomerase activators were discovered via fungal biotransformation, which in turn necessitated optimization of their production. It is practical to improve the production processes by implementing the design of experiment (DoE) strategy, leading to increased yield and productivity. In this study, we focused on optimizing biotransformation conditions utilizing Camarosporium laburnicola, a recently discovered filamentous fungus, to afford the target telomerase activators (E-CG-01, E-AG-01, and E-AG-02).

RESULTS

DoE approaches were used to optimize the microbial biotransformation processes of C. laburnicola. Nine parameters were screened by Plackett-Burman Design, and three significant parameters (biotransformation time, temperature, shaking speed) were optimized using Central Composite Design. After conducting validation experiments, we were able to further enhance the production yield of target metabolites through scale-up studies in shake flasks (55.3-fold for E-AG-01, 13-fold for E-AG-02, and 1.96-fold for E-CG-01).

CONCLUSION

Following a process optimization study using C. laburnicola, a significant increase was achieved in the production yields. Thus, the present study demonstrates a promising methodology to increase the production yield of potent telomerase activators. Furthermore, C. laburnicola is identified as a potential biocatalyst for further industrial utilization.

Biotransformation of ursolic acid by Circinella muscae and their anti-neuroinflammatory activities of metabolites

In this study, the biotransformation of ursolic acid by Circinella muscae CGMCC 3.2695 was investigated. Scaled-up biotransformation reactions yielded ten metabolites. Their structures were established based on extensive NMR and HR-ESI-MS data analyses, and four of them are new compounds. C. muscae could selectively catalyze hydroxylation, lactonisation, carbonylation and carboxyl reduction reactions. Furthermore, all the identified metabolites were evaluated for their anti-neuroinflammatory activities in LPS-induced BV-2 cells. Most metabolites displayed pronounced inhibitory effect on nitric oxide (NO) production. The results suggested that biotransformed derivatives of ursolic acid might be served as potential neuroinflammatory inhibitors.

Biotransformation of Oleanane and Ursane Triterpenic Acids

Oleanane and ursane pentacyclic triterpenoids are secondary metabolites of plants found in various climatic zones and regions. This group of compounds is highly attractive due to their diverse biological properties and possible use as intermediates in the synthesis of new pharmacologically promising substances. By now, their antiviral, anti-inflammatory, antimicrobial, antitumor, and other activities have been confirmed. In the last decade, methods of microbial synthesis of these compounds and their further biotransformation using microorganisms are gaining much popularity. The present review provides clear evidence that industrial microbiology can be a promising way to obtain valuable pharmacologically active compounds in environmentally friendly conditions without processing huge amounts of plant biomass and using hazardous and expensive chemicals. This review summarizes data on distribution, microbial synthesis, and biological activities of native oleanane and ursane triterpenoids. Much emphasis is put on the processes of microbial transformation of selected oleanane and ursane pentacyclic triterpenoids and on the bioactivity assessment of the obtained derivatives.

Microbe-mediate transformation of echinocystic acid by whole cells of filamentous fungus Cunninghamella blakesleana CGMCC 3.910

Structural modification of echinocystic acid (EA), a pentacyclic triterpenoid with wide spread biological activities was investigated by microbial transformation. Microbe-mediate transformation of EA was carried out by filamentous fungus Cunninghamella blakesleana CGMCC 3.910. Four metabolites 3β, 7β, 16α-trihydroxy-olean-12-en-28-oic acid (EA-2); 3β, 7β, 16β,19β-tetrahydroxy-olean-12-en-28-oic acid (EA-3); 3β, 7β, 16α, 21β-tetrahydroxy-olean-12-en-28-oic acid (EA-4); 3β, 7β, 16α-trihydroxy-olean-11, 13(18)-dien-28-oic acid (EA-5) were produced. Structures of transformed products were elucidated by 1D and 2D NMR and HR-MS data. EA-3 and EA-4 were new compounds.