Microbial cyclic β-(1→3),(1→6)-glucans as potential drug carriers: Interaction studies between cyclic β-glucans isolated from Bradyrhizobium japonicum and betulinic acid

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2018-10, Vol.203, p.494-500
• Main Authors: Kambhampati, Naga Sai Visweswar, Kar, Swayamsiddha, Pinnepalli, Sai Siva Kumar, Chelli, Janardhana, Doble, Mukesh
• Format: Article
• Language: English
• Subjects: Betulinic acid; Bradyrhizobium japonicum; Cyclic β-(1 → 3),(1 → 6)-glucans; Drug binding; Drug carrier; Encapsulation
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2018.05.106

Betulinic acid (BA), a pentacyclic triterpenoid, is a very promising therapeutic drug with varied medicinal properties but it has low water solubility and consequentially low bioavailability. Cyclic β-(1→3),(1→6)-glucans (CBG), microbial cyclooligosaccharides produced by Bradyrhizobium japonicum ATCC 10324 having a cavity structure and good solubility in water have been tested for their ability to encapsulate betulinic acid and drug-binding interactions of CBG and BA were studied. First, in silico approach was employed to study the scope of any interaction between the CBG and BA. Then, the cyclic glucan-betulinic acid complexes were prepared in three compositions of 1:1, 1:2 and 1:3 CBG:BA. The complexes were analysed using UV-VIS spectroscopy, IR spectroscopy, powder XRD, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to confirm the computational results and consequently the encapsulation efficiency was found to be 9.53%. [Display omitted] •Cyclic β-(1→3),(1→6)-glucans were extracted from Bradyrhizobium japonicum bacteria.•Cyclic β-glucan and betulinic acid as host-guest system was studied in silico.•Analytical techniques were employed to verify in silico results.•Encapsulation was achieved with an efficiency of 9.53%.