Plasma-Induced Degradation of Quercetin Associated with the Enhancement of Biological Activities

Assessing anti oxidant, antidiabetic potential and GCMS profiling of ethanolic root bark extract of Zanthoxylum rhetsa (Roxb.) DC: Supported by in vitro, in vivo and in silico molecular modeling

Zanthoxylum rhetsa (ZR) is used traditionally to manage a variety of ailments, including diabetes. Oxidative stress may accelerate the diabetic condition. The available antidiabetic and antioxidant drugs have many shortcomings including resistance, inefficiency, higher dose, side effects and costs. The goal of the current investigation was to assess the antioxidant capacity and antidiabetic activity of an ethanolic extract of Zanthoxylum rhetsa root bark (ZRRB) through in vitro, in vivo, and in silico methods. The antioxidant capacity of the ZRRB extract was measured using both the DPPH radical assay and the total antioxidant activity test. The oral glucose tolerance test (OGTT) and alloxan-induced diabetic mice model were also used to examine in vivo antidiabetic efficacy. Phytochemicals identification was done by GCMS analysis. Additionally, computational methods such as molecular docking, ADMET analysis, and molecular dynamics (MD) modeling were performed to determine the above pharmacological effects. The extract demonstrated significant DPPH scavenging activity (IC50 = 42.65 μg/mL). In the OGTT test and alloxan-induced diabetes mice model, the extract effectively lowered blood glucose levels. Furthermore, in vitro inhibition of pancreatic α-amylase studies demonstrated the ZRRB extract as a good antidiabetic crude drug (IC50 = 81.45 μg/mL). GCMS investigation confirmed that the crude extract contains 16 major phytoconstituents, which were docked with human peroxiredoxin-5, α-amylase, and sulfonylurea receptor 1. Docking and pharmacokinetic studies demonstrated that among 16 phytoconstituents, 6H-indolo[3,2,1-de] [1,5]naphthyridin-6-one (CID: 97176) showed the highest binding affinity to targeted enzymes, and imitated Lipinski's rule of five. Furthermore, MD simulation data confirmed that the aforementioned compound is very steady to the binding site of α-amylase and sulfonylurea receptor 1 receptors. Findings from in vitro, in vivo and in silico investigation suggest that ZRRB extract contains a lead compound that could be a potent source of antidiabetic drug candidate.

Optimization of flavanonols heterologous biosynthesis in Streptomyces albidoflavus, and generation of auronols

Aromadendrin and taxifolin are two flavanonols (derived from the precursor naringenin) displaying diverse beneficial properties for humans. The carbon skeleton of these flavonoids may be transformed by the human gastrointestinal microbiota into other compounds, like auronols, which exert different and interesting biological activities. While research in flavonoids has become a certainly extensive field, studies about auronols are still scarce. In this work, different versions of the key plant enzyme for flavanonols biosynthesis, The flavanone 3-hydroxylase (F3H), has been screened for selecting the best one for the de novo production of these compounds in the bacterial factory Streptomyces albidoflavus UO-FLAV-004-NAR, a naringenin overproducer strain. This screening has rendered 2.6 μg/L of aromadendrin and 2.1 mg/L of taxifolin final production titers. Finally, the expression of the chalcone isomerase (CHI) from the gut bacterium Eubacterium ramulus has rendered a direct conversion (after feeding experiments) of 38.1% of (+)-aromadendrin into maesopsin and 74.6% of (+)-taxifolin into alphitonin. Moreover, de novo heterologous biosynthesis of 1.9 mg/L of alphitonin was accomplished by means of a co-culture strategy of a taxifolin producer S. albidoflavus and a CHI-expressing Escherichia coli, after the observation of the high instability of alphitonin in the culture medium. This study addresses the significance of culture time optimization and selection of appropriate enzymes depending on the desired final product. To our knowledge, this is the first time that alphitonin de novo production has been accomplished.

Flavonoids as dual-target inhibitors against α-glucosidase and α-amylase: a systematic review of in vitro studies

Diabetes mellitus remains a major global health issue, and great attention is directed at natural therapeutics. This systematic review aimed to assess the potential of flavonoids as antidiabetic agents by investigating their inhibitory effects on α-glucosidase and α-amylase, two key enzymes involved in starch digestion. Six scientific databases (PubMed, Virtual Health Library, EMBASE, SCOPUS, Web of Science, and WHO Global Index Medicus) were searched until August 21, 2022, for in vitro studies reporting IC50 values of purified flavonoids on α-amylase and α-glucosidase, along with corresponding data for acarbose as a positive control. A total of 339 eligible articles were analyzed, resulting in the retrieval of 1643 flavonoid structures. These structures were rigorously standardized and curated, yielding 974 unique compounds, among which 177 flavonoids exhibited inhibition of both α-glucosidase and α-amylase are presented. Quality assessment utilizing a modified CONSORT checklist and structure-activity relationship (SAR) analysis were performed, revealing crucial features for the simultaneous inhibition of flavonoids against both enzymes. Moreover, the review also addressed several limitations in the current research landscape and proposed potential solutions. The curated datasets are available online at https://github.com/MedChemUMP/FDIGA .

Low-Temperature Plasma Techniques in Biomedical Applications and Therapeutics: An Overview

Plasma, the fourth fundamental state of matter, comprises charged species and electrons, and it is a fascinating medium that is spread over the entire visible universe. In addition to that, plasma can be generated artificially under appropriate laboratory techniques. Artificially generated thermal or hot plasma has applications in heavy and electronic industries; however, the non-thermal (cold atmospheric or low temperature) plasma finds its applications mainly in biomedicals and therapeutics. One of the important characteristics of LTP is that the constituent particles in the plasma stream can often maintain an overall temperature of nearly room temperature, even though the thermal parameters of the free electrons go up to 1 to 10 keV. The presence of reactive chemical species at ambient temperature and atmospheric pressure makes LTP a bio-tolerant tool in biomedical applications with many advantages over conventional techniques. This review presents some of the important biomedical applications of cold-atmospheric plasma (CAP) or low-temperature plasma (LTP) in modern medicine, showcasing its effect in antimicrobial therapy, cancer treatment, drug/gene delivery, tissue engineering, implant modifications, interaction with biomolecules, etc., and overviews some present challenges in the field of plasma medicine.

Innovative Application of Cold Plasma Technology in Meat and Its Products

The growing demand for sustainable food production and the rising consumer preference for fresh, healthy, and safe food products have been driving the need for innovative methods for processing and preserving food. In the meat industry, this demand has led to the development of new interventions aimed at extending the shelf life of meats and its products while maintaining their quality and nutritional value. Cold plasma has recently emerged as a subject of great interest in the meat industry due to its potential to enhance the microbiological safety of meat and its products. This review discusses the latest research on the possible application of cold plasma in the meat processing industry, considering its effects on various quality attributes and its potential for meat preservation and enhancement. In this regard, many studies have reported substantial antimicrobial efficacy of cold plasma technology in beef, pork, lamb and chicken, and their products with negligible changes in their physicochemical attributes. Further, the application of cold plasma in meat processing has shown promising results as a potential novel curing agent for cured meat products. Understanding the mechanisms of action and the interactions between cold plasma and food ingredients is crucial for further exploring the potential of this technology in the meat industry, ultimately leading to the development of safe and high-quality meat products using cold plasma technology.

A DFT Study on the Kinetics of HOO•, CH3OO•, and O2•- Scavenging by Quercetin and Flavonoid Catecholic Metabolites

Reaction kinetics have been theoretically examined to ascertain the potency of quercetin (Q) and flavonoid catecholic metabolites 1-5 in the inactivation of HOO^•, CH₃OO^•, and O₂^•- under physiological conditions. In lipidic media, the koverallTST/Eck rate constants for the proton-coupled electron transfer (PCET) mechanism indicate the catecholic moiety of Q and 1-5 as the most important in HOO^• and CH₃OO^• scavenging. 5-(3,4-Dihydroxyphenyl)-γ-valerolactone (1) and alphitonin (5) are the most potent scavengers of HOO^• and CH₃OO^•, respectively. The koverallMf rate constants, representing actual behavior in aqueous media, reveal Q as more potent in the inactivation of HOO^• and CH₃OO^• via single electron transfer (SET). SET from 3-O^- phenoxide anion of Q, a structural motif absent in 1-5, represents the most contributing reaction path to overall activity. All studied polyphenolics have a potency of O₂^•- inactivation via a concerted two-proton-coupled electron transfer (2PCET) mechanism. The obtained results indicate that metabolites with notable radical scavenging potency, and more bioavailability than ingested flavonoids, may contribute to human health-promoting effects ascribed to parent molecules.

Atmospheric Pressure Cold Plasma Modification of Basil Seed Gum for Fabrication of Edible Film Incorporated with Nanophytosomes of Vitamin D3 and Tannic Acid

The purpose of this work was to first investigate the impact of cold plasma (CP) treatment, performed at various times (0-30 min), on the characteristics of basil seed gum (BSG), as well as the fabrication of functional edible films with the modified BSG. FT-IR spectra of CP-treated BSG revealed change at 1596 and 1718 cm^-1, indicating the formation of carbonyl groups. Both untreated and CP-modified BSG dispersions showed shear-thinning behavior with a higher apparent viscosity for the CP-modified dispersions at studied temperatures. Untreated BSG dispersion and the one treated by CP for 10 min revealed time-independent behavior, while those treated for 20 and 30 min showed a rheopectic behavior. CP-modified BSG dispersion had higher G', G″, and complex viscosity than untreated BSG. Higher contact angle for the CP-modified BSG suggested enhanced hydrophobic nature, while the surface tension was lower compared to the untreated BSG. SEM micrographs revealed an increase in the surface roughness of treated samples. Moreover, modified BSG was successfully used for the preparation of edible film incorporating tannic acid and vitamin D₃-loaded nanophytosomes with high stability during storage compared to the free form addition. The stability of encapsulated forms of vitamin D₃ and tannic acid was 39.77% and 38.91%, more than that of free forms, respectively. In conclusion, CP is an appropriate technique for modifying the properties of BSG and fabrication of functional edible films.

Effect of Atmospheric-Pressure Plasma on Functional Compounds and Physiological Activities in Peanut Shells

Peanut (Arachis hypogaea L.) shell, an abundant by-product of peanut production, contains a complex combination of organic compounds, including flavonoids. Changes in the total phenolic content, flavonoid content, antioxidant capacities, and skin aging-related enzyme (tyrosinase, elastase, and collagenase)-inhibitory activities of peanut shell were investigated after treatment in pressure swing reactors under controlled gas conditions using surface dielectric barrier discharge with different plasma (NOx and O3) and temperature (25 and 150 °C) treatments. Plasma treatment under ozone-rich conditions at 150 °C significantly affected the total phenolic (270.70 mg gallic acid equivalent (GAE)/g) and flavonoid (120.02 mg catechin equivalent (CE)/g) contents of peanut shell compared with the control (253.94 and 117.74 mg CE/g, respectively) (p < 0.05). In addition, with the same treatment, an increase in functional compound content clearly enhanced the antioxidant activities of components in peanut shell extracts. However, the NOx-rich treatment was significantly less effective than the O3 treatment (p < 0.05) in terms of the total phenolic content, flavonoid content, and antioxidant activities. Similarly, peanut shells treated in the reactor under O3-rich plasma conditions at 150 ℃ had higher tyrosinase, elastase, and collagenase inhibition rates (55.72%, 85.69%, and 86.43%, respectively) compared to the control (35.81%, 80.78%, and 83.53%, respectively). Our findings revealed that a reactor operated with O3-rich plasma-activated gas at 150 °C was better-suited for producing functional industrial materials from the by-products of peanuts.

Systematical Ingredient Investigations of Ficus tikoua Bur. Fruit and Immunoregulatory and Antioxidant Effects of Different Fractions

Although the fruit of Ficus tikoua Bur. has been consumed by montanic people in China for centuries, its chemical and biological composition was still unclear. A series of comprehensive investigations on its chemical constituents and bioactivities were carried out for the first time. As a result, six compounds were isolated and identified as the main components in this fruit. GC-MS analysis of the lipid components demonstrated that Ficus tikoua Bur. fruit contains some wholesome constituents such as fatty acids, vitamins, triterpenoids, and phytosterols. The fatty acids are mainly composed of linolenic acid (61.27%) and linoleic acid (22.79%). Furthermore, this fruit contains a relative high content of crude protein (9.41 ± 0.03%), total amino acids (9.28%), and total polyphenols (0.86 ± 0.01 g/100 g). The analysis of monosaccharide composition showed that the total polysaccharide mainly consists of glucose, glucuronic acid, xylose, arabinose, mannose, galactose, galacturonic acid, and rhamnose. The polysaccharide, polyphenol, water, ethanol, and flavonoid extracts exhibited prominent antioxidant activity determined by ABTS, DPPH, and FRAPS methods. Meanwhile, the total polysaccharide exhibited significant immunomodulatory effect by enhancing the release of cytokines and expression of iNOS and COX-2 in RAW264.7 cells, significantly decreasing the expression of c-Jun and p65 proteins in the cytoplasm; increasing the translocation of c-Jun and p65 to the nucleus; and regulating the phosphorylation level of Akt, PI3K, and PDK1 in the PI3K/AKT signaling pathway. This study proved that the fruit of F. tikoua is a reliable source of functional food.

Chemical constituents of Entandrophragma angolense and their anti-inflammatory activity

From the stem bark of Entandrophragma angolense, six undescribed compounds were isolated, including seco-tirucallane type triterpenoids, limonoids, and a catechin glucoside, along with nineteen known structures. All structures were determined by interpretation of spectroscopic and HRMS data, and absolute configuration was confirmed with the aid of electronic circular dichroism. The isolated compounds were tested for LPS-induced NO inhibition in RAW 264.7 macrophages and EC₅₀ values for moluccensin O and (-)-catechin were 81 μM and 137 μM, respectively.

The genus Alphitonia Reissek ex Endl. (Rhamnaceae): A review of its customary uses, phytochemistry and biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Alphitonia Reissek ex Endl. is a relatively small genus of the family Rhamnaceae. Plants of this genus are found predominantly in the tropical regions of Southeast Asia, Australia and the Pacific, with some species being widely distributed and others endemic to a region. Almost half of the species of the Alphitonia genus have been reported for their customary (traditional and contemporary) medicinal uses. This includes for the treatment of skin conditions, headache, stomachache, inflammation, and body pain such as joint pain and childbirth.

AIM OF THE REVIEW

The aim of this review is to provide the first comprehensive account on the customary uses including ethnomedicinal uses, and phytochemistry and biological activities of the Alphitonia genus, and to identify gaps in current knowledge and scope for future research of plants of this genus.

MATERIALS AND METHODS

Information relevant to the genus Alphitonia was collected by searching the scientific databases (SciFinder, Google Scholar, ACS publications, PubMed, Wiley Online Library and International Plant name Index). Species names were validated using the World Flora Online database (www.worldfloraonline.org).

RESULTS

Eight plants from the Alphitonia genus have been reported to be used as customary medicines, i.e. A. excelsa, A. ferruginea, A. franguloides, A. incana, A. neocaledonica, A. petriei, A. philippinensis and A. zizyphoides. A. excelsa, A. petriei, A. philippinensis and A. zizyphoides, have been shown to have biological activities that align with their customary uses, including antimicrobial, antioxidant and anti-inflammatory activities. Only five Alphitonia species reported for their medicinal customary uses have been explored for their phytochemistry, i.e. A. excelsa, A. neocaledonica, A. petriei, A. philippinensis and A. zizyphoides. Compounds identified from these plants include those that are well known for their medicinal importance. A. macrocarpa, A. whitei and A. xerocarpus have also been examined for their phytochemistry and have been found to have the same or similar bioactive compounds to those found in customarily used Alphitonia species. No biological activities or phytochemistry studies have been reported for the known customarily used medicinal plants A. ferruginea, A. franguloides and A. incana.

CONCLUSIONS

This review highlights the customary uses, biological activities and phytochemistry of plants of the Alphitonia Reissek ex Endl. genus and highlights the significance of the knowledge systems of Indigenous peoples. Of the plants that have been researched for their biological activities and phytochemistry, there is good correlation with these properties and their customary medicinal uses. However, over half of the plants of the Alphitonia genus, including those that are already reported in the public domain for their customary medicinal uses, have had none or limited biological activities or phytochemistry studies conducted. While only eight species of the Alphitonia genus have been reported as customary medicines, other Alphitonia species also possess medicinally important compounds, and it is possible that they are customary medicines but their uses have not been shared publicly by the Indigenous knowledge custodians. There is clearly much scope for further investigation of this genus with regards to their ethnomedicinal uses and therapeutic potential.

Plasma-Induced Oxidation Products of (-)-Epigallocatechin Gallate with Digestive Enzymes Inhibitory Effects

(-)-Epigallocatechin gallate (EGCG), the chief dietary constituent in green tea (Camellia sinensis), is relatively unstable under oxidative conditions. This study evaluated the use of non-thermal dielectric barrier discharge (DBD) plasma to improve the anti-digestive enzyme capacities of EGCG oxidation products. Pure EGCG was dissolved in an aqueous solution and irradiated with DBD plasma for 20, 40, and 60 min. The reactant, irradiated for 60 min, exhibited improved inhibitory properties against α-glucosidase and α-amylase compared with the parent EGCG. The chemical structures of these oxidation products 1-3 from the EGCG, irradiated with the plasma for 60 min, were characterized using spectroscopic methods. Among the oxidation products, EGCG quinone dimer A (1) showed the most potent inhibitory effects toward α-glucosidase and α-amylase with IC50 values of 15.9 ± 0.3 and 18.7 ± 0.3 μM, respectively. These values were significantly higher than that of the positive control, acarbose. Compound 1, which was the most active, was the most abundant in the plasma-irradiated reactant for 60 min according to quantitative high-performance liquid chromatography analysis. These results suggest that the increased biological capacity of EGCG can be attributed to the structural changes to EGCG in H2O, induced by cold plasma irradiation.

Applications and challenges of low temperature plasma in pharmaceutical field

Low temperature plasma (LTP) technology has shown an outstanding application value in the pharmaceutical filed in recent ten years. This paper reviews the research advances in LTP, including its effects on enhancing or inhibiting drug activity, its combined use with drugs to treat cancers, its effects on the improvement of drug delivery system, its use in preparation of new inactivated virus vaccines, its use with mass spectrometry for rapid detection of drug quality, and the anti-tumor and sterilization effects of plasma-activated liquids. The paper also analyzes the challenges of LTP in the pharmaceutical filed, hoping to promote related research.

Chitosan Plasma Chemical Processing in Beam-Plasma Reactors as a Way of Environmentally Friendly Phytostimulants Production

A novel technique of phytoactive water-soluble chitooligosaccharide (COS) production in low-temperature plasma is described. Design, operation, and control of plasma chemical reactors used to produce COS from the powder of high molecular weight chitosan are presented. The electron beam plasma is strongly non-equilibrium and chemically active; plasma was excited by injecting the scanning electron beam into reaction volume filled with aerosol, containing oxygen and chitosan powder. Plasma chemical processes, responsible for the raw chitosan destruction and techniques of these processes to obtain control of products of optimal molecular weight, are considered. COS, in amounts sufficient for laboratory tests with some plants, were produced. Tests showed that the addition of COS into the liquid growing medium at 0.25 and 1 mg/mL stimulates root growth in Arabidopsis thaliana seedlings (Col-0) by up to 40%, with respect to control plants. Foliar application of these COS formulations at 0.25 mg/mL on tomato plants (cv. Micro-Tom) also resulted in increases between 11.9% and 36% in two important plant productivity indicators (flower and fruit numbers) compared to the control plants. Being environmentally friendly (and resource saving) the electron beam plasma technology of renewable natural biopolymer processing can be considered as a competitive way to produce biostimulants for commercial agriculture.

Synergistic bactericidal effect of clove oil and encapsulated atmospheric pressure plasma against Escherichia coli O157:H7 and Staphylococcus aureus and its mechanism of action

We investigated the bactericidal effect of clove oil and encapsulated atmospheric pressure plasma (EAP), individually or in combination, against Escherichia coli O157:H7 and Staphylococcus aureus. The bactericidal effect of the combined treatment was also investigated in inoculated beef jerky. For both pathogens, clove oil and EAP single treatments resulted in less than 3.0-log reductions, whereas the combined treatment resulted in more than 7.5-log reductions. The disc-diffusion assay and gas chromatography-mass spectrometry showed no changes in both the clear zone diameter and chemical composition of clove oil before and after the EAP treatment. Significant changes in cell membrane permeability and cell morphology resulting from the combined treatment of clove oil and EAP were evidenced by increased in UV absorption of cell supernatants, increased cell staining with propidium iodide, and changes in cell structure revealed by transmission electron microscopy. The synergistic bactericidal effects of clove oil and EAP against both pathogens were also observed in inoculated beef jerky, but the treatments were less effective against S. aureus, presumably due to thicker peptidoglycan layer. Experiments also demonstrated that the synergistic bactericidal effects between clove oil and EAP are due to clove oil increasing the susceptibility of the bacteria to subsequent EAP treatment, and does not involve alteration of the antibacterial activity of clove oil by EAP.

Factors influencing the antimicrobial efficacy of Dielectric Barrier Discharge (DBD) Atmospheric Cold Plasma (ACP) in food processing applications

Atmospheric cold plasma (ACP) is an emerging technology in the food industry with a huge antimicrobial potential to improve safety and extend the shelf life of food products. Dielectric barrier discharge (DBD) is a popular approach for generating ACP. Thanks to the numerous advantages of DBD ACP, it is proving to be successful in a number of applications, including microbial decontamination of foods. The antimicrobial efficacy of DBD ACP is influenced by multiple factors. This review presents an overview of ACP sources, with an emphasis on DBD, and an analysis of their antimicrobial efficacy in foods in open atmosphere and in-package modes. Specifically, the influence of process, product, and microbiological factors influencing the antimicrobial efficacy of DBD ACP are critically reviewed. DBD ACP is a promising technology that can improve food safety with minimal impact on food quality under optimal conditions. Once the issues pertinent to scale-up of plasma sources are appropriately addressed, the DBD ACP technology will find wider adaptation in food industry.

Nonthermal Plasma-Induced Degradation of Morin and Enhancement of Biological Activities

In the present study, non-thermal dielectric barrier discharge (DBD) plasma of induced structural changes of morin resulted in the isolation of one previously undescribed benzofuranone derivative, along with two known compounds. The chemical structures of these degradation products were elucidated by UV, NMR and FAB-MS spectroscopic analyses. The isolated three compounds showed potent antioxidative activities in two different tests, with IC₅₀ values in the range of 12.9-41.8 μm in the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺ ) radical scavenging activity, 19.0-71.9 μm for hydroxyl radical scavenging activity test. Furthermore, the new methoxylated benzofuranone exhibited enhancement of inhibitory effects against pancreatic lipase with an IC₅₀ value of 90.7±1.6 μm, when compared to the parent morin. These results suggested that the degradation products isolated from plasma exposed morin might be beneficial for prevention of obesity and related diseases.

Plasma-Polymerized Phlorotannins and Their Enhanced Biological Activities

Here, we investigated the effect of cold plasma (CP) on the biological activities of phloroglucinol. Phloroglucinol (7.92 and 15.84 mM in methanol) was treated with air dielectric barrier discharge plasma at 250 W. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferrous-reducing antioxidant power (FRAP) values of phloroglucinol increased in plasma treatment in a time-dependent manner. CP treatment of phloroglucinol decreased the lipid oxidation of oil emulsion during storage and increased the antimicrobial activity against Bacillus cereus, Escherichia coli O157:H7, and Staphylococcus aureus. Angiotensin-converting enzyme (ACE) inhibitory activity of phloroglucinol increased and total phenolic content decreased based on CP treatment. The CP-induced polymerization of phloroglocinol to phlorotannin derivatives was identified using high-performance liquid chromatography with UV detector and electrospray ionization/mass spectrometry (HPLC-UV-ESI/MS) method. Consequently, the polymer structure of phloroglucinol was found in the CP-treated phloroglucinol. In addition, CP enhances the biological activity of phloroglucinol and could be applied to bioactive materials in food and related industries.

A green chemical oligomerization of phloroglucinol induced by plasma as novel α-glucosidase inhibitors

A new facile method was developed for simple green synthesis of methylene-bridged phloroglucinol oligomers using nonthermal dielectric barrier discharge (DBD) plasma in methanolic solution. The chemical structures of these newly generated oligomers 2-5 were determined by interpretation of the spectroscopic data, and the inhibitory activity toward α-glucosidase of all isolates was evaluated. The unusual phloroglcuinol pentamer 5 connected by four methylene linkages showed a much higher potential inhibitory effect against α-glucosidase than the other generated oligomers 2-4 and appeared to be a promising lead for development as a potential antidiabetic agent. Abbreviations: T2DM, type2 diabetes mellitus; DBD, dielectric barrier discharge; HPLC, high-performance liquid chromatography; IC50, 50% inhibition concentration; NMR, nuclear magnetic resonance; FABMS, fastatom bombardment mass spectrometry.

Gamma irradiation-assisted degradation of rosmarinic acid and evaluation of structures and anti-adipogenic properties

Radiation is a promising technique for improving the safety and shelf-life of processed foods. In the present investigation, the degradation mechanism and bioactivity improvement of rosmarinic acid (RA) were studied in response to various gamma irradiation doses (10, 20, and 50 kGy). RA exposed to gamma irradiation at 50 kGy was completely degraded and showed an increased inhibitory effect against 3 T3-L1 preadipocyte compare to the parent compound. Structures of the newly generated compounds 2-4 from irradiated RA at 50 kGy were elucidated based on spectroscopic methods, including 1H nuclear magnetic resonance (NMR) and mass spectrometry (MS). Interestingly, compounds 2 and 5 exhibited significantly enhanced anti-adipogenic properties in 3 T3-L1 cells compared to the original compound. These results provide evidence that structural changes in RA induced by gamma irradiation might enhance biological efficacy.