Structural characterization and immunological activity of pectin polysaccharide from kiwano (Cucumis metuliferus) peels

Minqian Zhu; Riming Huang; Peng Wen; Ya Song; Baolin He; Jialing Tan; Huili Hao; Hong Wang

doi:10.1016/j.carbpol.2020.117371

Structural characterization and immunological activity of pectin polysaccharide from kiwano (Cucumis metuliferus) peels

Carbohydr Polym. 2021 Feb 15:254:117371. doi: 10.1016/j.carbpol.2020.117371. Epub 2020 Nov 24.

Authors

Minqian Zhu¹, Riming Huang², Peng Wen³, Ya Song⁴, Baolin He⁵, Jialing Tan⁶, Huili Hao⁷, Hong Wang⁸

Affiliations

¹ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: zhuminqian@stu.scau.edu.cn.
² Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: huangriming@scau.edu.cn.
³ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: wenpeng100@163.com.
⁴ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: songya_1990@163.com.
⁵ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: hebaolin@scau.edu.cn.
⁶ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: 995340450@qq.com.
⁷ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: hhlhaohuili@stu.scau.edu.cn.
⁸ Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address: gzwhongd@163.com.

PMID: 33357887
DOI: 10.1016/j.carbpol.2020.117371

Abstract

Two novel polysaccharides, namely CMPP-1 and CMPP-2, from kiwano (Cucumis metuliferus) peels were isolated through hot-water extraction, followed by ethanol precipitation and column chromatography. The results showed that CMPP-1 and CMPP-2 were hetero-galacturonans with different molecular weights of 7.35 kDa and 6.90 kDa, respectively. Both of CMPP-1 and CMPP-2 were mainly composed of glucuronic acid (45.93 % and 51.75 %, respectively), and other monosaccharides including rhamnose, arabinose, galactose, glucose, xylose, fucose, mannose, galacturonic acid, and mannuronic acid. The results of structural characterization from FT-IR and NMR confirmed that CMPP-1 and CMPP-2 were pectin with highly branched structure. Furthermore, both CMPP-1 and CMPP-2 possessed immune-enhancing activity and could enhance the secretion of nitric oxide and cytokines (TNF-α, IL-6) in a dose-dependent manner. Especially, CMPP-1 had higher immune activity than CMPP-2 as the minimum effective concentration were 0.78 μg/mL and 6.25 μg/mL, respectively. These findings provide a scientific basis for further utilization of polysaccharide from kiwano peels.

Keywords: Immunological activity; Kiwano (Cucumis metuliferus) peels; Pectin polysaccharide; Structural characterization.

MeSH terms

Adjuvants, Immunologic / chemistry*
Adjuvants, Immunologic / isolation & purification
Adjuvants, Immunologic / pharmacology*
Animals
Cell Survival / drug effects
Cucumis / chemistry*
Cytokines / metabolism
Fruit / chemistry*
Glucuronic Acid
Macrophages / drug effects
Macrophages / immunology
Mice
Molecular Structure
Molecular Weight
Monosaccharides
Pectins / chemistry*
Pectins / isolation & purification
Pectins / pharmacology*
Plant Extracts / chemistry*
Plant Extracts / isolation & purification
Plant Extracts / pharmacology*
RAW 264.7 Cells
Signal Transduction / drug effects

Substances

Adjuvants, Immunologic
Cytokines
Monosaccharides
Plant Extracts
Pectins
Glucuronic Acid