Activity, reduced toxicity, and scale-up synthesis of amphotericin B-conjugated polysaccharide.
Amphotericin B (AMB) arabinogalactan (AG) conjugate was synthesized by the conjugation of AMB to oxidized AG by reductive amination. The conjugate was evaluated for in vitro antifungal activity and in vivo toxicity. Optimization of the conjugation process was investigated using large batches of 100 g, which are 20 times larger than previously reported for AMB-AG conjugation. The efficacy of AMB-AG conjugates was studied as a function of reaction conditions and time, aldehyde/reducing agent mole ratio, and purification procedure. The most potent AMB-AG conjugate having low minimal inhibitory concentration (MIC) and high maximal tolerated dose (MTD) was obtained following reduction with NaBH4 at 1:2 mol ratio (AG units/NaBH4) at 25 °C for 24 h. AMB-AG conjugate prepared under these conditions demonstrated MIC of 0.5 mg/L (equiv of AMB) in Candida albicans, and an MTD of 60 mg/kg (equiv of AMB) in mice, while AMB clinical formulation (Fungizone) demonstrated high toxicity (MTD = 3 mg/kg). These findings confirm the simplicity and reproducibility of the conjugation allowing this method to be applied on larger scale production.
Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem , Jerusalem 91120, Israel.
Diana E
DE
Ickowicz
Shimon
S
Farber
Edward
E
Sionov
Sarah
S
Kagan
Amnon
A
Hoffman
Itzhack
I
Polacheck
Abraham J
AJ
Domb
D000666:Amphotericin B / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000627:therapeutic use / Q000633:toxicity; D000818:Animals; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology; D002177:Candidiasis / Q000188:drug therapy / Q000473:pathology; D002522:Chlorocebus aethiops; D005685:Galactans / Q000138:chemical synthesis* / Q000627:therapeutic use / Q000633:toxicity*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D051381:Rats; D011917:Rats, Inbred Lew; D012756:Sheep; D014709:Vero Cells
D005685:Galactans; C492445:amphotericin B-arabinogalactan conjugate; D000666:Amphotericin B