Methylcobalamin – A form of vitamin B12 identified and characterised in Chlorella vulgaris

• The focus was to identify the forms of vitamin B12 in Chlorella vulgaris.
• LCMS, MS/MS along with SIR, MRM and gold nanoparticle based RNA aptamer were used.
• Microbiological, chemiluminescence and AuNPs based aptamer was used for quantification.
• Around 28.24 ± 2 μg/100 g dry weight of methylcobalamin was found in Chlorella vulgaris.

Vitamin B12 is among the most essential biomolecules required for crucial metabolic processes in humans. Vitamin B12 was extracted from Chlorella vulgaris biomass under aqueous conditions, partially purified by passing the extract through amberlite XAD-2, Sep-Pak columns, and further purified by HPLC. The target peak eluent was subjected to characterisation by tandem mass spectrometry (MS/MS), selected ion recording (SIR) and multiple reaction monitoring (MRM) and identified as methylcobalamin (Me-Cbl). Quantification of Me-Cbl was carried out by microbiological and chemiluminescence methods, and found to be 29.87 ± 2 μg/100 g and 26.84 ± 2 μg/100 g dry weight, respectively. The presence of Me-Cbl was further substantiated using gold nanoparticle (AuNPs) based aptamer analysis, and found to be 28.02 ± 2 μg/100 g dry weight. Good similarity was observed among all the methods. Methylcobalamin, a form of vitamin B12 was identified in C. vulgaris and this finding enhances its use as a nutritional supplement.