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Updated: Nov 22, 2025
Separation of Bioactive Small Molecules, Peptides from Natural Sources and Proteins from Microbes by Preparative Isoelectric Focusing IEF Method
Published on: June 14, 2020
Serine-glycine-betaine, a novel dipeptide from an endophyte Macrophomina phaseolina: isolation, bioactivity and
G Singh1,2, J Singh2,3, V Singamaneni2,4
1Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, India.
Aims:
Endophytes are a rich source for structurally complex chemical scaffolds with interesting biological activities. Endophytes associated with Brugmansia aurea L. (family: Solanaceae), a medicinal plant, have not yet explored for the bioactive metabolites.
Method And Results:
Hence, Macrophomina phaseolina, a fungal endophyte, was isolated from the roots of the plant. Its methanolic extract was found active against human cancer cell lines with IC50 <20 µg ml-1 . Later, a di-peptide compound, serine-glycine-betaine, was isolated and characterized. Serine-glycine-betaine consists of a unit of an N-trimethyl glycine attached to serine. It exhibited potent activity against MIA PaCa-2 and HCT-116 cell lines with IC50 8·9 and 15·16 μmol l-1 , respectively. Furthermore, it induced apoptosis in MIA PaCa-2 cells confirmed by microscopy. The apoptotic cell death in MIA PaCa-2 cells was evidenced biochemically with the generation of intracellular reactive oxygen species level and leading to loss of mitochondrial membrane potential due to activation of the intrinsic pathway. This study describes the plausible biosynthesis of serine-glycine-betaine based on genomics (genome sequencing, annotation and genes alignment).
Conclusions:
A novel di-peptide, serine-glycine-betaine isolated from M. phaseolina induced apoptosis in MIA-Pa-Ca-2 cells.
Significance And Impact Of The Study:
This study confirms that dipeptides like serine-glycine-betaine and tyrosine-betaine might be specific to fungal genera, hence being used for diagnostic purposes.
