Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Citrobacter freundii [ICD11:
XN0M3 
]
The structure was elucidated in this paperNCBI PubMed ID: 33316341Publication DOI: 10.1016/j.ijbiomac.2020.12.063Journal NLM ID: 7909578Publisher: Butterworth-Heinemann
Correspondence: mondalsoumitra78
yahoo.com; bhattacharyya_nandan
rediffmail.com
Institutions: Department of Biotechnology, Panskura Banamali College, P.O. - Panskura R.S., Purba Medinipur, West Bengal PIN-721152, India, Department of Chemistry, Sabang Sajanikanta Mahavidyalaya, Sabang, Paschim Midnapore, West Bengal PIN-721166, India, Dept. of Microbiology, Vidyasagar University, Medinipur, West Bengal PIN-721102, India, Department of Life Sciences, CHRIST (Deemed to be University), Bengaluru PIN-560029, India, Department of Chemistry, Panskura Banamali College, P.O. - Panskura R.S., Purba Medinipur, West Bengal PIN-721152, India
This study aimed to investigate the molecular characterization, antioxidant activity in vitro, cytotoxicity study of an exopolysaccharide isolated from Citrobacter freundii. Firstly, the culture conditions were standardized by the Design of experiments (DoE) based approach, and the final yield of thecrude exopolysaccharide was optimized at 2568 ± 169 mg L-1. One large fraction of exopolysaccharide was obtained from the culture filtrate by size exclusion chromatography and molecular characteristics were studied. A new mannose rich exopolysaccharide (Fraction-I) with average molecular weight ~ 1.34 × 105 Da was isolated. The sugar analysis showed the presence of mannose and glucose in a molar ratio of nearly 7:2 respectively. The structure of the repeating unit in the exopolysaccharide was determined through chemical and 1D/2D- NMR experiments as: Finally, the antioxidant activity, and the cytotoxicity of the exopolysaccharide were investigated and the relationship with molecular properties was discussed as well.
structure, exopolysaccharide, cytotoxicity, Citrobacter freundii, Antioxidant activity, NMR studies
Structure type: polymer chemical repeating unit ; 134000
Location inside paper: abstract, p. 541, table 1a, p. 547, fraction-I (EPS)
Compound class: EPS
Contained glycoepitopes: IEDB_130701,IEDB_137485,IEDB_140116,IEDB_141793,IEDB_142488,IEDB_144983,IEDB_146664,IEDB_152206,IEDB_153220,IEDB_76933,IEDB_983930,IEDB_983931,SB_192,SB_198,SB_44,SB_67,SB_72
Methods: 13C NMR, 1H NMR, methylation, GLC-MS, NMR-2D, sugar analysis, acid hydrolysis, GLC, GPC, statistical analysis, antioxidant activities, cytotoxicity assay, radical scavenging assay
Biological activity: fraction-I (EPS) exhibits cytotoxicity against HeLa cells after 48 h, and almost nontoxic to HEK-293 cells
NCBI Taxonomy refs (TaxIDs): 546
Show glycosyltransferases
NMR conditions: in D2O at 303 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
4,4,4,4,4,4 aDManp 97.9 69.1 68.9 78.7 74.8 61.0
4,4,4,4,4,6 aDManp 100.5 70.0 69.8 66.7 73.2 61.0
4,4,4,4,4 aDManp 101.9 69.1 70.3 78.4 74.2 65.5
4,4,4,4 aDManp 102.6 69.1 68.6 78.1 74.8 61.0
4,4,4 aDManp 100.0 69.1 70.4 78.4 74.8 61.0
4,4,6 bDGlcp 100.9 73.1 75.1 69.6 75.6 61.0
4,4 bDManp 99.5 69.1 73.1 78.2 75.6 65.8
4 bDGlcp 102.6 74.2 75.6 77.0 75.0 61.0
aDManp 98.6 69.1 70.4 78.7 74.8 61.0
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
4,4,4,4,4,4 aDManp 4.94 4.08 3.73 3.87 3.50 3.61-3.87
4,4,4,4,4,6 aDManp 5.14 3.93 3.86 3.58 3.66 3.61-3.87
4,4,4,4,4 aDManp 4.99 4.08 3.78 3.97 3.45 3.61-3.87
4,4,4,4 aDManp 4.90 4.08 3.67 3.82 3.50 3.61-3.87
4,4,4 aDManp 4.89 4.08 3.66 3.97 3.50 3.61-3.87
4,4,6 bDGlcp 4.59 3.24 3.49 3.34 3.36 3.61-3.87
4,4 bDManp 4.75 4.09 3.64 3.81 3.37 3.61-3.87
4 bDGlcp 4.60 3.45 3.67 3.78 3.47 3.61-3.87
aDManp 4.96 4.08 3.69 3.87 3.50 3.61-3.87
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
4,4,4,4,4,4 aDManp 97.9/4.94 69.1/4.08 68.9/3.73 78.7/3.87 74.8/3.50 61.0/3.61-3.87
4,4,4,4,4,6 aDManp 100.5/5.14 70.0/3.93 69.8/3.86 66.7/3.58 73.2/3.66 61.0/3.61-3.87
4,4,4,4,4 aDManp 101.9/4.99 69.1/4.08 70.3/3.78 78.4/3.97 74.2/3.45 65.5/3.61-3.87
4,4,4,4 aDManp 102.6/4.90 69.1/4.08 68.6/3.67 78.1/3.82 74.8/3.50 61.0/3.61-3.87
4,4,4 aDManp 100.0/4.89 69.1/4.08 70.4/3.66 78.4/3.97 74.8/3.50 61.0/3.61-3.87
4,4,6 bDGlcp 100.9/4.59 73.1/3.24 75.1/3.49 69.6/3.34 75.6/3.36 61.0/3.61-3.87
4,4 bDManp 99.5/4.75 69.1/4.09 73.1/3.64 78.2/3.81 75.6/3.37 65.8/3.61-3.87
4 bDGlcp 102.6/4.60 74.2/3.45 75.6/3.67 77.0/3.78 75.0/3.47 61.0/3.61-3.87
aDManp 98.6/4.96 69.1/4.08 70.4/3.69 78.7/3.87 74.8/3.50 61.0/3.61-3.87
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
|---|
| 4,4,4,4,4,4 | aDManp | 4.94 | 4.08 | 3.73 | 3.87 | 3.50 | 3.61
3.87 |
| 4,4,4,4,4,6 | aDManp | 5.14 | 3.93 | 3.86 | 3.58 | 3.66 | 3.61
3.87 |
| 4,4,4,4,4 | aDManp | 4.99 | 4.08 | 3.78 | 3.97 | 3.45 | 3.61
3.87 |
| 4,4,4,4 | aDManp | 4.90 | 4.08 | 3.67 | 3.82 | 3.50 | 3.61
3.87 |
| 4,4,4 | aDManp | 4.89 | 4.08 | 3.66 | 3.97 | 3.50 | 3.61
3.87 |
| 4,4,6 | bDGlcp | 4.59 | 3.24 | 3.49 | 3.34 | 3.36 | 3.61
3.87 |
| 4,4 | bDManp | 4.75 | 4.09 | 3.64 | 3.81 | 3.37 | 3.61
3.87 |
| 4 | bDGlcp | 4.60 | 3.45 | 3.67 | 3.78 | 3.47 | 3.61
3.87 |
| | aDManp | 4.96 | 4.08 | 3.69 | 3.87 | 3.50 | 3.61
3.87 |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
|---|
| 4,4,4,4,4,4 | aDManp | 97.9 | 69.1 | 68.9 | 78.7 | 74.8 | 61.0 |
| 4,4,4,4,4,6 | aDManp | 100.5 | 70.0 | 69.8 | 66.7 | 73.2 | 61.0 |
| 4,4,4,4,4 | aDManp | 101.9 | 69.1 | 70.3 | 78.4 | 74.2 | 65.5 |
| 4,4,4,4 | aDManp | 102.6 | 69.1 | 68.6 | 78.1 | 74.8 | 61.0 |
| 4,4,4 | aDManp | 100.0 | 69.1 | 70.4 | 78.4 | 74.8 | 61.0 |
| 4,4,6 | bDGlcp | 100.9 | 73.1 | 75.1 | 69.6 | 75.6 | 61.0 |
| 4,4 | bDManp | 99.5 | 69.1 | 73.1 | 78.2 | 75.6 | 65.8 |
| 4 | bDGlcp | 102.6 | 74.2 | 75.6 | 77.0 | 75.0 | 61.0 |
| | aDManp | 98.6 | 69.1 | 70.4 | 78.7 | 74.8 | 61.0 |
|
There is only one chemically distinct structure:
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Found 1 record.
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