| Abstract: |
Taxolisoneofthepotentialanticancerdrugs;however,theyieldofTaxolanditscytotoxicity arecommonchallenges. Thus,manipulatingtheTaxolbiosyntheticpathwayfromendophyticfungi,in additiontochemicalmodificationwithbiocompatiblepolymers,isthechallenge. Fourfungalisolates, namely, Aspergillusflavipes, A.terreus, A.flavus, and A.parasiticus, were selected from our previous studyaspotentialTaxolproducers,andtheirpotencyforTaxolproductionwasevaluatedinresponse to fluconazole and silver nitrate. A higher Taxol yield was reported in the cultures of A. flavipes (185 µg/L) and A. terreus (66 µg/L). With addition of fluconazole, the yield of Taxol was increased 1.8 and 1.2-fold for A. flavipes and A. terreus, respectively, confirming the inhibition of sterol biosynthesis and redirecting the geranyl phosphate pool to terpenoids synthesis. A significant inhibition of ergosterol biosynthesis by A. flavipes with addition of fluconazole was observed, correlating with the increase on Taxol yield. To increase the Taxol solubility and to reduce its cytotoxicity, Taxol was modified via chemical conjugation with porphyrin, and the degree of conjugation was checked from the Thin layer chromatography and UV spectral analysis. The antiproliferative activity of native and modified Taxol conjugates was evaluated; upon porphyrin conjugation, the activity of Taxol towards HepG2 was increased 1.5-fold, while its cytotoxicity to VERO cells was reduced 3-fold.
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