Purified novel and new diferuloyl glycerate related phenolic acid from Pandanus odoratissimus flowers shows antioxidant, invertase inhibition and control against diabetic foot ulcer (DFU) causing bacterial pathogens - An in vitro study to establish an effective regulation over type 2 diabetes mellitus

Abstract Chronic type 2 diabetes mellitus (T2DM) and its associated diseases are major concern among human population and also responsible for significant mortality rate. Hence, the present study aims to evaluate and correlate the invertase inhibition, antioxidant activity and control against DFU causing bacterial pathogens by Pandanus odoratissimus flowers. Two dimensional preparative thin layer chromatography (2D PTLC) was adopted to purify the phenolic acid component and LC-MS2 was done to predict the phenolic acid structures. Standard spectrophotometry methods were adopted to investigate the in vitro invertase inhibitory and antioxidant (CUPRAC and ABTS) activities. Agar well diffusion and broth dilution assays were used to record the antibacterial property against DFU causing pathogens isolated from clinical samples. Statistical analyses were used to validate the experiments. A new and novel diferuloyl glycerate related phenolic acid (m/z 442) purified from PTLC eluate has recorded satisfactory cupric ion reducing power (ED50= 441.4±2.5 µg), moderate ABTS radical scavenging activity (IC50= 450.3±10 µg; 32.5±1.5%), and a near moderate, in vitro, invertase mixed type inhibition (24.5±4.5%; Ki: 400 µg). Similarly, bacterial growth inhibitory kinetics has showed a significant inhibition against E. coli and S. aureus.

Extraction process optimization of polyphenols from Indian Citrus sinensis - as novel antiglycative agents in the management of diabetes mellitus.

BACKGROUND: Diabetes mellitus is a chronic metabolic disorder characterized by increased blood glucose level. It has become an epidemic disease in the 21st century where, India leads the world with largest number of diabetic subjects. Non-enzymatic glycosylation (glycation) is severe form of diabetes, occurs between reducing sugar and proteins which results in the formation of advanced glycation end products (AGEs) that leads to the other complicated secondary disorders. In this context, Mangifera indica (Mango), Syzygium cumini (Jambul), Vitis vinifera (Grapes), Citrus sinensis (Orange), Artocarpus heterophyllus (Jackfruit), Manilkara zapota (Sapodilla) seeds were evaluated for their antiglyation activity. Attempts were made to isolate the polyphenols in the seeds that have recorded the maximum activity. METHODS: Different extraction methods (shake flask, centrifugation and pressurized hot water) using various extractants (organic solvents, hot water and pressurized hot water) were adopted to investigate the in vitro antiglycation activity. Central composite (CCD) design based Response Surface Methodology (RSM) was espoused to optimize the extraction process of polyphenols from the fruit seeds that have recorded poor antiglycation activity. The PTLC analysis was performed to isolate the polyphenols (Flavonoids and phenolic acids) and LC-PDA-MS analysis was done for structure prediction. RESULTS: Pressurized hot water extraction of Artocarpus heterophyllus (87.52%) and Citrus sinensis seeds (74.79%) was found to possess high and low antiglycation activity, respectively. The RSM mediated optimization process adopted for the Citrus sinensis seeds have revealed that 1:15 solvent ratio (hexane to heptane), 6 minutes and 1:20 solid to liquid ratio as the optimal conditions for the extraction of polyphenols with a maximum antiglycation activity (89.79%). The LC-PDA-MS analysis of preparative thin layer chromatography (PTLC) eluates of Artocarpus heterophyllus seed has showed the presence of compounds like quercetin (301.2), 4-hydroxy phenyl acetic acid (149.0), rhamnosyl-di-hexosyl quercetin sulphate (857.6), quercetin-3-O-xyloside (428.2), rutin (613.4), diosmetin (298.1) and luteolin (283.0). CONCLUSION: The Artocarpus heterophyllus was observed to possess a significant antiglycation activity and the activity of Citrus sinensis was improved after the optimization process, which proved that both the seeds may be used as a traditional medicine in the management of chronic diabetes mellitus.

Induction and purification by three-phase partitioning of aryl alcohol oxidase (AAO) from Pleurotus ostreatus.

Aryl alcohol oxidase (AAO) is an extracellular flavoenzyme involved in lignin degradation by white rot fungi. Screening of lignolytic and AAO activity from twenty different fungal species were carried out. Among them, seven species showed lignolytic activity and three of them (Pleurotus ostreatus, Pleurotus eous, and Pleurotus platypus) were found to be AAO positive. Maximal AAO activity was observed in batch cultures of P. ostreatus and was found to be induced by aromatic amino acids and aryl alcohols up to a level of 289 U/l. Purification of AAO was carried out by three-phase partitioning (TPP). The 67 kDa enzyme was purified up to 10.19-fold by TPP with an overall recovery of 10.95%. Optimum pH and temperature for P. ostreatus AAO activity was found to be around 6 and 40 °C, respectively. From the LB plot, K (m) value of AAO for oxidizing veratryl alcohol was determined to be 0.6 mM. Results of the study indicate that P. ostreatus is the best producers of AAO, and they could be employed as promising fungal species for biotechnological applications.