Extraction, characterization of xylan from Azadirachta indica (neem) sawdust and production of antiproliferative xylooligosaccharides

• Published in: International journal of biological macromolecules Vol. 163; pp. 1897 - 1907
• Main Authors: Sharma, Kedar, Morla, Sudhir, Khaire, Kaustubh Chandrakant, Thakur, Abhijeet, Moholkar, Vijayanand Suryakant, Kumar, Sachin, Goyal, Arun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.11.2020
• Subjects: apoptosis; Azadirachta - chemistry; Azadirachta indica; biocompatibility; cell growth; Cell Proliferation - drug effects; colorectal neoplasms; Colorectal Neoplasms - drug therapy; denaturation; DNA; DSC; fibroblasts; flow cytometry; glucuronic acid; Glucuronoxylan; HT29 Cells; Human colorectal cancer (HT-29) cells; Humans; Hydrolysis; membrane potential; mice; mitochondrial membrane; molecular weight; MTT; Neem; NMR; Oligosaccharides - chemistry; Oligosaccharides - isolation & purification; Oligosaccharides - pharmacology; polymerization; sawdust; thermogravimetry; Wood - chemistry; xylan; Xylans - chemistry; Xylans - isolation & purification; Xylans - pharmacology; xylooligosaccharides; xylose; Xylose - chemistry; NMR; Glucuronoxylan; Neem; MTT; DSC; Human colorectal cancer (HT-29) cells
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.09.086

Xylan extracted from neem sawdust gave 22.5%, (w/w) yield. The extracted xylan was composed of xylose and glucuronic acid at a molar ratio of 8:1 and with a molecular mass, ~66 kDa. FTIR and NMR analyses indicated a backbone of xylan substituted with 4-O-methyl glucuronic acid at the O-2 position. FESEM analysis showed a highly porous and granular surface structure of xylan. A thermogravimetric study of xylan showed thermal denaturation at 271 °C. The hydrolysis of xylan by recombinant endo-β-1,4-xylanase produced a mixture of xylooligosaccharides ranging from degree of polymerization 2–7. Xylooligosaccharides inhibited cell growth of human colorectal cancer (HT-29) cells but did not affect the mouse fibroblast cells confirming its biocompatibility. Western blotting, DNA laddering and flow cytometric analysis displayed inhibition of HT-29 cells by xylooligosaccharides. FLICA staining and mitochondrial membrane potential analyses confirmed the activation of the intrinsic pathway of apoptosis. The study amply indicated that the xylooligosaccharides produced from neem xylan could be potentially used as an antiproliferative agent.