Vitamin K (Menaquinone) from marine Kocuria sp. RAM1: optimization, characterization and potential in vitro biological activities.

Abstract

Background: Menaquinone (MK), which is also known as vitamin K2, is a kind of lipoquinone that, unlike humans, is biosynthesized in bacteria through a series of steps as a necessary component of their respiratory chain for electron transport among various components of the bacterial cell membrane. MKs are receiving increasing attention as they play several essential biological roles in humans.

Results: In this study, MK was obtained from Kocuria sp. RAM1, characterized using UV absorbance, and validated using nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS). The chemical characterization revealed a total of six MK analogues that were identified and confirmed as MK-1, MK-3, MK-5 (H2), MK-7 (H6), MK-8 (H2), and MK-9. Subsequent to the execution of a significant optimization model, a total KMs of 394.69 µg/ml was obtained, with the MK-1 analog being the dominant one. The antibacterial, anti-inflammatory, antioxidant, anticancer, antidiabetic, and wound-healing activities of MKs were evaluated in vitro. As a result, we discovered that MKs have promising findings on the tested in vitro activities.

Conclusions: Our study was made to evaluate MKs obtained from the Red Sea Kocuria sp. RAM1 to emphasize their significant role in different biological applications. Therefore, from a therapeutic and medicinal perspective, the extracted MKs are interesting for additional in vivo studies.