Glycosyltransferase; part of the gene cluster that mediates the biosynthesis fumihopaside A, a hopane-type glucoside that enhances the thermotolerance and UV resistance of N.fumigata (PubMed:30977375). The first step of fumihopaside A biosynthesis is performed by the squalene hopane cyclase afumA that catalyzes the cyclization of 3S-oxidosqualene into the hopene 21-beta-H-hopane-3-beta,22-diol (PubMed:30977375). The cytochrome P450 monooxygenase afumB is responsible for both hydroxylation at C-24 and oxidations at C-30 of the afumA product (PubMed:30977375). The glycosyltransferase afumC then catalyzes the glycosylation at C-24, using UDP-D-glucose as a donor, to produce fumihopaside A (PubMed:30977375). AfumC is also able to accept UDP-D-galactose and UDP-D-glucuronic acid as donors to yield minor derivatives (PubMed:30977375). Fumihopaside B, another minor derivative produced, is different from fumihopaside A due to the presence of a double bond between C-22 and C-29 (PubMed:30977375). Activity is significantly decreased by addition of divalent cations such as Mg(2+), Mn(2+), Zn(2+), Ca(2+), Co(2+), Cu(2+), and Ni(2+); while Fe(2+) has little effect. Optimum pH is 8.0. Optimum temperature is 37 degrees Celsius. Secondary metabolite biosynthesis. Failed to produce fumihopaside A, but leads to the accumulation of the aglycone intermediate. Belongs to the afumC glycosyltransferase family.