HPTLC-based fingerprinting: An alternative approach for fructooligosaccharides metabolism profiling

Quality variation of maidong (Ophiopogon japonicus and Liriope spicata) - A HPTLC-based approach

The tuberous roots of Ophiopogon japonicus and Liriope spicata are used for the same therapeutic purpose in traditional Chinese medicine and are collectively referred to as maidong medicine. Interestingly, it was observed that the price of tuberous roots varies depending on their location on the plant, and fibrous roots are usually discarded post-harvest. Mislabeling might be of concern due to similarities in morphological features between the two species. Moreover, paclobutrazol has been observed to be heavily applied during the production, and therefore might be of health concern. Overall, maidong might suffer from quality inconsistencies while its metabolomic complexity is influenced by growing region and cultivation practices, botanical species, and plant parts. To address these challenges, this study employed High-Performance Thin Layer Chromatography (HPTLC) approach, in which sample preparation and derivatization procedure were optimized to enable to capture more detailed and comprehensive metabolomic fingerprints. By integrating with rTLC algorithm and Multivariate Data Analysis (MVDA), an improved quality assessment was achieved. Samples were collected from four production regions and supplemented with commercial products from markets. The optimized HPTLC analysis recognized species- and region-specific metabolomic patterns of maidong, uncovering a 4% of mislabelled cases. Moreover, findings highlight the underexplored therapeutic potential of fibrous roots, and comparable therapeutic efficacy between different root types. Additionally, complemented by Liquid Chromatography-Mass Spectrometry (LC-MS) for paclobutrazol residue evaluation, 24.66% of the commercial maidong samples surpassed maximum residue limits of paclobutrazol, raising safety concerns. This research represents a significant analytical advancement, offering a robust, cost-effective, and comprehensive method for maidong quality control, and paving the way for more strict residue regulation and updates to herbal pharmacopoeias and monographs.

The agavins (Agave carbohydrates) story

Fructans, are carbohydrates defined as fructose-based polymers with countable degree of polymerization (DP) ranging so far from DP3 to DP60. There are different types of fructans depending on their molecular arrangement. They are categorized as linear inulins and levans, neoseries of inulin and levan, branched graminans, and highly branched neofructans, so called agavins (Agave carbohydrates). It is worth to note that agavins are the most recently described type of fructans and they are also the most complex ones. The complexity of these carbohydrates is correlated to their various isomers and degree of polymerization range, which is correlated to their multifunctional application in industry and human health. Here, we narrate the story of the agavins' discovery. This included their chemical characterization, their benefits, biotechnological applications, and drawbacks over human health. Finally, a perspective of the study of agavins and their interactions with other metabolites through metabolomics is proposed.

Agave amica a potential model for the study of agavins metabolism

Fructans found in agave are called agavins, highly branched neo-fructans. They are essential on the yield and quality of Tequila production. The need for agave specimens with higher accumulation of agavins became essential before the growing demand of such products. To get such specimens, understanding agavins metabolism is a quintessential requirement. For this, a more efficient biological model is required. The recently reclassified Agave amica possesses the potential to gather the requirements for becoming such a model. Therefore, this study dealt with the characterization of carbohydrates in the bulbs of A. amica focusing on fructans. Moreover, it tested and described its feasibility as model for the accelerated study of agavins. Infrared analysis unveiled potential content of fructans in the bulbs of A. amica. Furthermore, high performance thin layer chromatography detected fructooligosaccharides. High performance anion exchange chromatography confirmed a polydisperse mixture of branched fructans. Gas chromatography-mass spectrometry analysis demonstrated agavins like structures in the bulbs of A. amica. Moreover, total fructan content and multivariate data analysis through bulb's age demonstrated their correlation. Thus, the presence of agavins, their correlation with phenology, and their technical advantages highlighted the feasibility of this species as a potential new biological model for the study of agavins' metabolism.