Effect of Side Chain Functional Groups on the DPPH Radical Scavenging Activity of Bisabolane-Type Phenols

Synthesis and Biological Evaluation of Some New 3-Aryl-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones and 3-Aryl-2-(benzylthio)quinazolin-4(3H)-ones as Antioxidants; COX-2, LDHA, α-Glucosidase and α-Amylase Inhibitors; and Anti-Colon Carcinoma and Apoptosis-Inducing Agents

Oxidative stress, COX-2, LDHA and hyperglycemia are interlinked contributing pathways in the etiology, progression and metastasis of colon cancer. Additionally, dysregulated apoptosis in cells with genetic alternations leads to their progression in malignant transformation. Therefore, quinazolinones 3a-3h and 5a-5h were synthesized and evaluated as antioxidants, enzymes inhibitors and cytotoxic agents against LoVo and HCT-116 cells. Moreover, the most active cytotoxic derivatives were evaluated as apoptosis inducers. The results indicated that 3a, 3g and 5a were efficiently scavenged DPPH radicals with lowered IC50 values (mM) ranging from 0.165 ± 0.0057 to 0.191 ± 0.0099, as compared to 0.245 ± 0.0257 by BHT. Derivatives 3h, 5a and 5h were recognized as more potent dual inhibitors than quercetin against α-amylase and α-glucosidase, in addition to 3a, 3c, 3f and 5b-5f against α-amylase. Although none of the compounds demonstrated a higher efficiency than the reference inhibitors against COX-2 and LDHA, 3a and 3g were identified as the most active derivatives. Molecular docking studies were used to elucidate the binding affinities and binding interactions between the inhibitors and their target proteins. Compounds 3a and 3f showed cytotoxic activities, with IC50 values (µM) of 294.32 ± 8.41 and 383.5 ± 8.99 (LoVo), as well as 298.05 ± 13.26 and 323.59 ± 3.00 (HCT-116). The cytotoxicity mechanism of 3a and 3f could be attributed to the modulation of apoptosis regulators (Bax and Bcl-2), the activation of intrinsic and extrinsic apoptosis pathways via the upregulation of initiator caspases-8 and -9 as well as executioner caspase-3, and the arrest of LoVo and HCT-116 cell cycles in the G2/M and G1 phases, respectively. Lastly, the physicochemical, medicinal chemistry and ADMET properties of all compounds were predicted.

Composition and Antioxidative and Antibacterial Activities of the Essential Oil from Farfugium japonicum

The composition of volatile oils of the leaf and stem of Farfugium japonicum (L.) Kitamura were prepared by supercritical fluid extraction (SFE)-CO₂. A total 47 and 40 compounds were identified by GC/MS analysis, respectively, and only 13 compounds coexisted. The main constituent types in the leaf oil included alcohols (34.1%), hydrocarbons (24.1%), terpenoids (16.2%), benzenes (7.5%), and fatty acids (4.9%). In the stem oil, the constituent types chiefly included benzenes (18.8%), ketones (13.9%), terpenoids (17.0%), fatty acids (8.8%), phenolics (8.7%), steroids (8.6%), hydrocarbons (8.0%), and esters (5.7%). The predominant volatile compounds in the stem were 2-(1-cyclopent-1-enyl-1-methylethyl) cyclopentanone (11.7%), 1,2,3,4,5,6,7,8-octahydro- 9,10-dimethyl-anthracene (8.4%), 5-heptylresorcinol (6.5%), and α-sitosterol (5.2%). Those in the leaf mainly included (E)-3-hexen-1-ol (13.7%) and (Z)-3-hexen-1-ol (14.0%). This demonstrated a significant difference in the composition of both oils. Further study showed that stem oils demonstrated the highest DPPH (1,1-diphenyl-2-pinylhydrazyl) and ·OH free radical scavenging capacities at IC₅₀ values of 9.22 and 0.90 mg/mL, respectively. In addition, they demonstrated the strongest antibacterial capacity against the Gram-positive bacteria methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) at a minimum inhibitory concentration (MIC) of 0.16 mg/mL. This could be due to the SFE-CO₂ extraction and the high accumulation of benzenes, terpenoids, and phenolics in the stem. In particular, the monoterpenes presented in terpenoids could play a special role in these findings.

Antioxidative Indenone and Benzophenone Derivatives from the Mangrove-Derived Fungus Cytospora heveae NSHSJ-2

Seven new polyketides, including four indenone derivatives, cytoindenones A–C (1, 3–4), 3′-methoxycytoindenone A (2), a benzophenone derivative, cytorhizophin J (6), and a pair of tetralone enantiomers, (±)-4,6-dihydroxy-5-methoxy-α-tetralone (7), together with a known compound (5) were obtained from the endophytic fungus Cytospora heveae NSHSJ-2 isolated from the fresh stem of the mangrove plant Sonneratia caseolaris. Compound 3 represented the first natural indenone monomer substituted by two benzene moieties at C-2 and C-3. Their structures were determined by the analysis of 1D and 2D NMR, as well as mass spectroscopic data, and the absolute configurations of (±)-7 were determined on the basis of the observed specific rotation value compared with those of the tetralone derivatives previously reported. In bioactivity assays, compounds 1, 4–6 showed potent DPPH· scavenging activities, with EC50 values ranging from 9.5 to 16.6 µM, better than the positive control ascorbic acid (21.9 µM); compounds 2–3 also exhibited DPPH· scavenging activities comparable to ascorbic acid.

Antioxidant activity of venison subjected to in vitro cooking and gastrointestinal digestion and isolation of its 2,2-diphenyl-1-picrylhydrazyl radical scavenging peptides

Venison, a type of game meat, has several health benefits because it contains not only high protein and low fat but also bioactive peptides with several physiological properties, including antioxidative and angiotensin-converting enzyme inhibitory properties. The aim of the present study was to investigate the antioxidant activity of venison treated by in vitro cooking and gastrointestinal digestion. We subjected venison along with pork and beef to in vitro cooking and digestion and assessed their antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH-RS) and hydrophilic oxygen radical absorbance capacity (H-ORAC) assays. The peptide contents of all types of cooked and digested meat samples were higher than those of the untreated and cooked samples. The DPPH-RS activities and H-ORAC of digested venison, pork, and beef were increased compared with those of untreated samples. DPPH-RS activity was significantly higher in the digested venison samples than in the digested pork and beef samples. In this study, several fractions of digested venison from the chromatography exhibited DPPH-RS activity. Peptide analysis, using liquid-chromatography with tandem mass spectrometry, unveiled two peptides DIDDLELTLAK and TQTVCNFTDGALVQHQEWDGK with high DPPH-RS activities. Thus, venison is a rich source of antioxidant peptides and potentially demonstrate an antioxidation ability by digestive enzymes in vivo.

High-performance carboxymethyl cellulose-based hydrogel film for food packaging and preservation system

Most traditional food packaging and preservation films suffer from limited stretchability and relatively simple functionality, which severely restricts their practical application. In this study, a highly stretchable and versatile sodium carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA)/poly(ethylene imine) (PEI)/tannic acid (TA) hydrogel film was elaborately designed and demonstrated as an efficient food packaging and preservation system. The dynamic reversible non-covalent within three-dimensional (3D) network structures served as sacrificial bonds to dissipate the loaded energy and endowed the hydrogel film with excellent elongation ~400 %, which is much larger than that of conventional food packaging films (<50 %). Furthermore, the optimized CMC/PVA/PEI/TA₃ hydrogel film delivers versatile performances, including self-healing, whole UV-blocking (<400 nm), strong adhesive strength (234.08 KPa), antioxidation virtues, oxygen barrier (32.64 cm³*μm/(m²*d*KPa)) and water vapor barrier (642.92 g/(m²*24 h)). Notably, the shelf life of fresh strawberries, mangoes, and cherries was prolonged by at least one week under ambient conditions when the packaging box was covered by the fabricated CMC/PVA/PEI/TA₃ film. Thus, our work not only provides a highly stretchable and versatile hydrogel film but also boosts the in-depth comprehension and rational design of robust food packaging and preservation films.

Xanthorrhizol, a potential anticancer agent, from Curcuma xanthorrhiza Roxb

BACKGROUND

Xanthorrhizol (XTZ), a bisabolene sesquiterpenoid, is abundantly found in the plant Curcuma xanthorrhiza Roxb. Traditionally, C. xanthorrhiza is widely used for the treatment of different health conditions, including common fever, infection, lack of appetite, fatigue, liver complaints, and gastrointestinal disorders. XTZ exhibits wide-ranging pharmacological activities, including anticancer, antioxidative, anti-inflammatory, antimicrobial, and antidiabetic activities, in addition to a protective effect on multiple organs. The present review provides detailed findings on the anticancer activities of XTZ and the underlying cellular and molecular mechanisms.

METHODS

Literature was searched systematically in main databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, with keywords "tumor AND xanthorrhizol" or "cancer AND xanthorrhizol".

RESULTS

Studies show that XTZ has preventive and therapeutic activities against different types of cancer, including breast, cervical, colon, liver, lung, oral and esophageal, and skin cancers. XTZ regulates multiple signaling pathways that block carcinogenesis and proliferation. In vitro and in vivo studies showed that XTZ targets different kinases, inflammatory cytokines, apoptosis proteins, and transcription factors, leading to the suppression of angiogenesis, metastasis, and the activation of apoptosis and cell cycle arrest.

CONCLUSION

The potential anticancer benefits of XTZ recommend further in vivo studies against different types of cancer. Further, XTZ needs to be confirmed for its toxicity, bioavailability, protective, antifatigue, and energy booster activities. Future studies for the therapeutic development of XTZ may be directed to cancer-related fatigue.

The Gut Microbiota Metabolite Urolithin B Improves Cognitive Deficits by Inhibiting Cyt C-Mediated Apoptosis and Promoting the Survival of Neurons Through the PI3K Pathway in Aging Mice

Background: Despite considerable advances in pharmacotherapy, more effective therapeutic interventions for aging-related neurodegenerative disorders (NDs), such as Alzheimer’s disease (AD), remain limited. Urolithin B (UB), one of the major subcategories of urolithins (microbiota metabolites) found in various tissues after ellagitannin consumption, has been shown to possess antioxidant, anti-inflammatory, and antiapoptotic effects. However, the neuroprotective effect of UB on brain aging in mice and its potential mechanisms were still unknown.

Methods: In the current research, we first assessed the ameliorative effects of UB on oxidative injury and apoptosis induced by H₂O₂ in neuro-2a cells. Then a subcutaneous injection of D-galactose in mice for 8 weeks was used to establish the aging model to evaluate the protective effects of UB. The capacity of memory and learning, alterations of hippocampus histology and corresponding molecular mechanisms were all evaluated.

Results: The D-gal-induced accelerated aging model in vivo demonstrated that UB could significantly ameliorate deficits in learning and memory by inhibiting the accumulation of advanced glycation end products (AGEs) and elevating the expression and activity of Cu, Zn-SOD and CAT. Furthermore, UB downregulated the c-Jun N-terminal kinase (JNK) signaling pathway and prevented cytochrome c release from isolated mitochondria, thereby inhibiting neuronal apoptosis during the aging process. More importantly, UB stimulation of aging mice activated ERK and phosphoinositide 3-kinase (PI3K), leading to neuronal survival along with Akt and p44/42 mitogen-activated protein kinase (MAPK) phosphorylation and activation.

Conclusion: In summary, UB effectively alleviated cognitive deficits and ameliorated brain aging-related conditions and could be considered a healthcare product to prevent aging-associated NDs such as AD.

Chitosan nanoparticles based on their derivatives as antioxidant and antibacterial additives for active bioplastic packaging

Chitosan nanoparticles (CSNPs) based on their different derivatives were proposed as antioxidant and antimicrobial additives for active bioplastic packaging. Chitosan was modified with polyethylene glycol methyl ether methacrylate (PEGMA), stearyl methacrylate (SMA) and deoxycholic acid (DC) using radiation-induced graft polymerization and chemical conjugation. The modified CSNPs-g-pPEGMA, CSNPs-g-pSMA and CSNPs-DC self-assembled into nanoparticles with the size in the range of 25-60 nm. The CSNPs-DC derivative has superior antioxidant activity and the CSNPs-g-pSMA derivative exhibited outstanding antibacterial activity against growth of E.coli (95.33 %). All modified CSNPs showed their capacities to inhibit S.aureus bacterial growth (>98 %). PLA packaging films containing CSNPs-g-pSMA inhibited the growth of natural microorganism on bread slices. Different chemical functions of the CSNPs derivatives provided different gas permeability and mechanical properties of the PLA films. The CSNPs derivatives would be promising antioxidant and antimicrobial additives for bioplastics to be further used as bio-based active food packaging.

Antioxidant Activity of Various Soluble Melanoidins Isolated from Black Garlic after Different Thermal Processing Steps

To gain insight into the antioxidant activity of various soluble melanoidins isolated from black garlic after different thermal processing steps, the antioxidant activity was evaluated. Black garlic was produced in a ripening chamber using a programmed stepwise heating schedule as follows: Step 1, 90°C and 100% (RH) for 34 h; Step 2, 60°C and 60% RH for 6 h; Step 3, 75°C and 70% RH for 48 h; Step 4, 70°C and 60% RH for 60 h; Step 5, 65°C and 50% RH for 192 h. The melanoidins isolated from black garlic after the different thermal processing steps were divided into different melanoidin fractions, i.e., melanoidins, pure melanoidin, bound melanoidin compounds (BMC). The antioxidant activity of the melanoidins bound to low molecular weight compounds (BMC fraction) was generally higher than those of the pure melanoidins. Notably, the antioxidant activity of various soluble melanoidins differed according to the thermal processing steps. The results may be useful in predicting the behavior of various soluble melanoidins during thermal processing of garlic.

Anti-Inflammatory Activity and ROS Regulation Effect of Sinapaldehyde in LPS-Stimulated RAW 264.7 Macrophages

We evaluated the anti-inflammatory effects of SNAH in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by performing nitric oxide (NO) assays, cytokine enzyme-linked immunosorbent assays, Western blotting, and real-time reverse transcription-polymerase chain reaction analysis. SNAH inhibited the production of NO (nitric oxide), reactive oxygen species (ROS), tumor necrosis factor (TNF)-α, and interleukin (IL)-6. Additionally, 100 μM SNAH significantly inhibited total NO and ROS inhibitory activity by 93% (p < 0.001) and 34% (p < 0.05), respectively. Protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) stimulated by LPS were also decreased by SNAH. Moreover, SNAH significantly (p < 0.001) downregulated the TNF-α, IL-6, and iNOS mRNA expression upon LPS stimulation. In addition, 3–100 µM SNAH was not cytotoxic. Docking simulations and enzyme inhibitory assays with COX-2 revealed binding scores of −6.4 kcal/mol (IC₅₀ = 47.8 μM) with SNAH compared to −11.1 kcal/mol (IC₅₀ = 0.45 μM) with celecoxib, a known selective COX-2 inhibitor. Our results demonstrate that SNAH exerts anti-inflammatory effects via suppression of ROS and NO by COX-2 inhibition. Thus, SNAH may be useful as a pharmacological agent for treating inflammation-related diseases.

The Antioxidant Capability of Higenamine: Insights from Theory

Density functional theory was employed to highlight the antioxidant working mechanism of higenamine in aqueous and lipid-like environments. Different reaction mechanisms were considered for the reaction of higenamine with the •OOH radical. The pH values and the molar fraction at physiological pH were determined in aqueous solution. The results show that the preferred reaction mechanism was the hydrogen atom transfer from the catecholic ring. The computed kinetic constants revealed that, in order to obtain reliable results, it is important to consider all the species present in water solution derived from acid-base equilibria. From the present investigation, it emerges that at physiological pH (7.4), the scavenging activity of higenamine against the •OOH radical is higher than that of Trolox, chosen as a reference antioxidant. Furthermore, higenamine results to be more efficient for that purpose than melatonin and caffeine, whose protective action against oxidative stress is frequently associated with their reactive oxygen species (ROS) scavenging activity.

Phytochemical Screening and Antioxidant Activity of Ethanolic Extract of Cawat Hanoman Stem (Bauhinia aculeata L.) using DPPH Method

The free radical is an unstable molecule because contains one or two unpaired electrons. The antioxidant substance is a simple way to decrease the illness caused by free radicals. Cawat hanoman (Bauhinia aculeata L.) was known to contain tannin components one of the benefits as an antioxidant. This research aims to determine the antioxidant activity of the B. aculeata stem tested by qualitatively used thin-layer chromatography (TLC) and quantitatively using the DPPH method. Bauhinia aculeata stem was extracted using a maceration extract method with 96% ethanol. Antioxidant activity test was done qualitatively by eluent of ethyl acetate : methanol : purified water (6 : 2 : 1) using TLC and quantitatively using the DPPH method. The result of antioxidant activity from 96% ethanol extract of B. aculeata stem qualitatively showed the presence of yellow spots on a purple background at TLC after syringed DPPH 0.5 mM and quantitative test that resulted in an IC50 of 21.862 �g/mL. These results indicate that 96% ethanol extract of B. aculeata has very strong antioxidant activity.

In Vitro Antioxidant Activity and FTIR Characterization of High-Molecular Weight Melanoidin Fractions from Different Types of Cocoa Beans

Melanoidins from real foods and model systems have received considerable interest due to potential health benefits. However, due to the complexity of these compounds, to date, the exact structure of melanoidins and mechanism involved in their biological activity has not been fully elucidated. Thus, the aim of this study was to investigate the total phenolic content, antioxidant properties, and structural characteristics of high-molecular weight (HMW) melanoidin fractions isolated by dialysis (>12.4 kDa) from raw and roasted cocoa beans of Criollo, Forastero, and Trinitario beans cultivated in various area. In vitro antioxidant properties of all studied HMW cocoa fractions were evaluated by four different assays, namely free radical scavenging activity against DPPH^• and ABTS^•+ radicals, ferric reducing antioxidant power (FRAP), and metal-chelating ability. Additionally, the structure–activity relationship of isolated HMW melanoidin fractions were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The results show that roasting at a temperature of 150 °C and a relative air humidity of 0.3% effectively enhances the total phenolics content and the antioxidant potential of almost all HMW cocoa melanoidin fractions. The ATR-FTIR analysis revealed that the various mechanisms of action of HMW melanoidins isolates of different types of cocoa beans related to their structural diversity. Consequently, the results clearly demonstrated that HMW cocoa fractions isolated from cocoa beans (especially those of Criollo variety) roasted at higher temperatures with the lower relative humidity of air possess high antioxidant properties in vitro.

Synthesis, Structural Studies, and α-Glucosidase Inhibitory, Antidiabetic, and Antioxidant Activities of 2,3-Dihydroquinazolin-4(1H)-ones Derived from Pyrazol-4-carbaldehyde and Anilines

A series of new quinazoline derivatives were designed and synthesized via a one-pot condensation reaction between isatoic anhydride and aromatic aldehydes with anilines using aluminum sulfate as a catalyst in refluxing ethanol. Their structures were confirmed by their physical, IR, 1H NMR, 13C NMR, and mass spectroscopy data and evaluated for some biological effects, including the antioxidant and α-glucosidase inhibitory activities as well as some in vivo hematological parameters. The ability of synthesized compounds in the inhibition of α-glucosidase was also investigated through the in silico study. The significant and important changes in some hematological tests were perceived. Notably, compound 4h showed more reducing effects on cholesterol and triglyceride levels. This molecule certainly has the potential to be developed as the antihyperlipemic compound. The tested compounds, in particular, compounds 4j and 4l, were found to be uniquely reducing blood sugar levels. The entire synthesized compounds showed the potent α-glucosidase inhibitory activity compared with acarbose as a standard material. Amongst, the compounds 4h and 4i showed the strongest enzyme inhibitory potentials than the standard drug acarbose. There was a good correlation between in vitro and in silico studies for ligands 4i and 4l. The majority of compounds presented a good radical scavenging activity, though the compound 4j exhibited the strongest activity, even to the standard of ascorbic acid. Further studies are required to determine whether these main compounds could be a potential treatment for diabetes and hyperlipidemia diseases.

A Theoretical and Experimental Study for Screening Inhibitors for Styrene Polymerization

Styrene is one of the most important monomers utilized in the synthesis of various polymers. Nevertheless, during distillation, storage, and transportation of ST, undesired polymer (i.e., UP) formation can take place. Thus, the control of undesired polymerization of styrene is a challenging issue facing industry. To tackle the mentioned issue, the antipolymer and antioxidant activity of stable nitroxide radicals (i.e., SNRs) and phenolics in styrene polymerization were studied by density functional theory (DFT) calculation and experimental approach. The electrophilicity index and growth percentage have been determined by DFT calculation and experimental approach, respectively. It is depicted that 2,6-di-tert-butyl-4-methoxyphenol (DTBMP) and 2,6-di-tert-butyl-4-methylphenol (BHT) from phenolics, and 4-hydroxy-2,2,6,6-tetramethyl piperidine 1-Oxyl (4-hydroxy-TEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine 1-Oxyl (4-oxo-TEMPO) from stable nitroxide radicals were the most effective inhibitors. Also, the growth percentage of DTMBP, BHT, 4-hydroxy-TEMPO, and 4-oxo-TEMPO after 4 h were 16.40, 42.50, 24.85, and 46.8, respectively. In addition, the conversion percentage of DTMBP, BHT, 4-hydroxy-TEMPO, and 4-oxo-TEMPO after 4 h were obtained to be 0.048, 0.111, 0.065, and 0.134, respectively. Furthermore, the synergistic effect of these inhibitors was investigated experimentally, indicating that DTMBP/4-hydroxy-TEMPO exerted the best synergistic effects on the inhibition of polymerization. The optimum inhibition effect was observed at the blend of 4-hydroxy-TEMPO (25 wt.%) and DTMBP (75 wt.%,) corresponding to 6.8% polymer growth after 4 h.