Isolation and characterization of cyclotides from the leaves of Viola odorata L. using peptidomic and bioinformatic approach

Comprehensive Mapping of Cyclotides from Viola philippica by Using Mass Spectrometry-Based Strategy

Cyclotides are plant cyclic peptides with exceptional stability and diverse bioactivity, making them promising candidates for biomedical applications. Therefore, the study of cyclotides has attracted increasing attention in recent years. However, the existing cyclotide detection methods face limitations in sensitivity, accuracy, and reliability. To address these challenges, we developed an integrated strategy using a combination of strong cation exchange chromatography techniques for removing interfering small molecules, Orbitrap Exploris 480 mass spectrometry (OEMS); this is a detection and database searching-based method for cyclotide verification, which greatly improved the sensitivity, accuracy, and reliability of cyclotide identification. This strategy was subsequently employed for cyclotide mapping in Viola with a minute amount of starting tissue, resulting the identification of 65 known and 18 potentially novel cyclotides, which is the largest dataset of cyclotides for Viola philippica. This strategy provided valuable insights into the cyclotide diversity and distribution in V. philippica, with potential applications in drug discovery and other biomedical fields.

Diversity analysis of endophytes with antimicrobial and antioxidant potential from Viola odorata: an endemic plant species of the Himalayas

Viola odorata, also known as "Banafshah" in high altitudes of Himalayas, is well known for its pharmaceutical importance in Ayurvedic and Unani medicinal system. The plant is a source of various drugs for its anti-inflammatory, diaphoretic, diuretic, emollient, expectorant, antipyretic, and laxative properties. The endophytes of plants have been reported for their role in modulating various physiological and biological processes of the host plants. In the present study, a total of 244 endophytes were isolated in pure cultures from the roots of Viola odorata, and genetic diversity was evaluated using amplified ribosomal DNA restriction analysis (ARDRA) and enterobacterial repetitive intergenic consensus (ERIC). The molecular fingerprinting revealed variation among various rRNA types among morphologically different endophytes based on ARDRA and ERIC-PCR. The screening of endophytes showed antimicrobial activity of 11 bacterial isolates and one actinomycete SGA9 against various pathogens Bacillus cereus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The antioxidant activity revealed the majority of the bacterial isolates able to scavenge the free radical in the range of 10-50% and 8 bacterial isolates in the range of 50-85%. Principal component analysis separated eight isolates away from the central eclipse and form a separate group based on antimicrobial and antioxidant potential. The identification of these eight isolates showed affiliation with different species of the genus Enterobacter, Microbacterium, Pseudomonas, Rhizobium, and Streptomyces. This is the first report on the characterization of endophytic bacteria and actinomycetes from endemic Viola odorata. Results suggested that these endophytes could be explored for the production of antimicrobial and antioxidant products.