Polyphenol Characterization,Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark

In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel .) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP‐LC‐DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose‐dependent antioxidant and free‐radical scavenging activity, expressed as half‐maximal inhibitory concentration (IC₅₀): Oxygen radical absorbance capacity (ORAC, IC₅₀ 1.78 μg mL^?1)>Trolox equivalent antioxidant capacity (TEAC, IC₅₀ 3.47 μg mL^?1)>2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH, IC₅₀ 5.83 μg mL^?1)>β‐carotene bleaching (IC₅₀ 11.58 μg mL^?1)>Ferric reducing antioxidant power (FRAP, IC₅₀ 17.28 μg mL^?1). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC₅₀ 77.44 μg mL^?1), l ‐DOPA auto‐oxidation (IC₅₀ 39.58 μg mL^?1) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.     

Evaluation of antioxidant capacities of green microalgae

Three strains of green microalgae, Chlorococcum sp.C53, Chlorella sp. E53, and Chlorella sp.ED53 were studied for their antioxidant activities. Crude extracts of these microalgae in hot water and in ethanol were examined for their total phenolic contents and for their antioxidant capacities. In order to determine their phenolic contents, the Folin–Ciocalteu method was used. As for the determination of their antioxidant capacities, four different assays were used: (1) total antioxidant capacity determination; (2) DPPH radical scavenging assay; (3) ferrous ion chelating ability assay; and (4) inhibition of lipid peroxidation (using thiobarbituric acid reactive substance). For all the strains we have studied, their ethanolic extract showed more antioxidant activities than their hot water extract. Categorically, the ethanolic extract of Chlorella sp.E53 exhibited both the highest total phenolic content of 35.5?±?0.14 mg gallic acid equivalent (GAE) g^?1 dry weight and the highest DPPH radical scavenging of 68.18?±?0.38 % at 1.4 mg mL^?1 (IC₅₀ 0.81 mg mL^?1), whereas Chlorella sp.ED53 showed both the highest ferrous ion chelation activity of 42.78?±?1.48 % at 1 mg mL^?1 (IC₅₀ 1.23 mg mL^?1) and the highest inhibition of lipid peroxidation of 87.96?±?0.59 % at 4 mg mL^?1. This high level of inhibition is comparable to 94.42?±?1.39 % of butylated hydroxytoluene, a commercial synthetic antioxidant, at the same concentration.     

Silene vulgaris subsp. macrocarpa leaves and roots from Morocco: assessment of the efficiency of different extraction techniques and solvents on their antioxidant capacity,brine shrimp toxicity and phenolic characterization

Abstract

This study was undertaken to investigate the effect of various solvents and techniques on the extractability of antioxidant compounds, particularly phenolics, from leaves and roots of Silene vulgaris subsp. macrocarpa grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. Aimed at establishing the potential safety of the extracts, Artemia salina lethality bioassay was performed. All the extracts were found to be non-toxic, except for the leaf Soxhlet ethanol. The antioxidant potential of the extracts was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. The leaf extracts displayed noticeable radical scavenging and chelating activities, and maceration with methanol (Mac-MeOH) resulted the most suitable extraction method for an effective recovery of antioxidants; further, the root Mac-MeOH extract demonstrated good chelating properties (IC₅₀ = 335.49?±?0.70?µg/mL). Thus, leaf and root Mac-MeOH extracts were subjected to phytochemical investigations. The total phenolic, flavonoid and condensed tannin content was determined spectrophotometrically. Thirteen polyphenolic compounds were positively identified, by HPLC-PDA-ESI-MS, in the leaf extract for the first time, with p-coumaric acid derivatives being the most abundant ones (81%), whereas only catechin and procyanidin B1 were found in the root extract.     

Phytochemical analysis and evaluation of antioxidant and anti-acetylcholinesterase activities of Euphorbia dendroides L. (Euphorbiaceae) latex

The aim of this study was to evaluate the antioxidant and anti-acetylcholinesterase properties and phytochemical constituents of the latex from Euphorbia dendroides L. (Euphorbiaceae) growing wild in Sicily. Phytochemical analysis revealed that into E. dendroides latex the triterpenoids were the most abundant among the identified compounds. Furthermore, a high content of polyphenols mainly as phenolic acids, was found. The antioxidant and free-radical scavenging properties, by several in vitro assays such as DPPH, TEAC and FRAP, have been evaluated. The results showed that E. dendroides latex has significant antioxidant activity, as measured by DPPH assay (2927.01?±?98.03 µmols of Trolox equivalent (TE)/100g FW). Reactivity towards ABTS radical cation and ferric-reducing antioxidant power (FRAP) values were 7580.95?±?97.65 µmols of TE/100g FW and 4383.13?±?95.30?μmol of TE/100g FW, respectively. The latex exhibited also significant inhibition of acetylcholinesterase activity with an IC₅₀ value of 4.46 µg/mL (C.L.?=?2.002–9.947). Furthermore, Brine shrimp (Artemia salina) cytotoxicity bioassay showed that the larvae viability was significantly affected at higher concentrations than those capable to induce significant antioxidant and anti-acetylcholinesterase effects (LD₅₀ 25 µg/mL). The results suggest that polyphenols and terpenoids can contribute significantly to antioxidant and anti-acetylcholinesterase activities of E. dendroides latex.     

香桃木叶片粗多酚抗氧化活性的研究

以香桃木叶片为材料,60%乙醇提取获得粗多酚样品,并对样品的油脂抗氧化性和自由基清除能力进行研究。结果表明,未经纯化的香桃木粗多酚对油脂抗氧化效果优于BHT和V_C等人工合成抗氧化剂;在清除自由基的实验中,相同浓度的香桃木粗多酚对DPPH自由基的清除率为V_E的5倍,对羟自由基的清除效果也略优于V_C。由此可以预见香桃木粗多酚在精细加工、经纯化后抗氧化效果会更加显著。     

Polyphenolic Content and Physiological Activities of Chinese Hawthorn Extracts

Hawthorn polyphenol (HP) was prepared by ethyl acetate treatment of the ethanol extract (HE) of Chinese hawthorn fruit. The concentrations of 15 polyphenols in the HP, HE, extraction residue (HJ), and a hawthorn leaf extract (HF) were determined by HPLC. For HP, the total content of the 15 polyphenols was 21.4%, comprised of 19.7% of procyanidins, 1.21% of chlorogenic acid, and 0.48% of flavonoids, compared to 2.55% for the HE. The yields of procyanidin monomer, dimer, trimer, tetramer, and pentamer were 50.5%, 30.3%, 23.0%, 14.6%, and 12.5% respectively, and the mean degree of polymerization was reduced to 1.39 (HP) from 1.65 (HE). Seven different physiological actions of the four extracts were investigated. The HP showed strong O₂ ^? and ^?OH scavenging capacities (IC₅₀ values of 6.3 μg/ml and 1.1 μg/ml respectively), as well as selective prolyl endopeptidase inhibition (IC₅₀ of 60 μg/ml). The active constituents appeared to be procyanidins.     

Isolation and biological activities of 3-hydroxy-4(1H)-pyridone

3-Hydroxy-4(4H)-pyridone (3,4-DHP), a degraded product of mimosine [β-[N-(3-hydroxy-4-oxypyridyl)]-α-aminopropionic acid], is known to cause goiters, loss of hair, and infertility in animals, but limits of 3,4-DHP on separation and purification have prevented efforts on investigating other toxicity and biological properties of 3,4-DHP. By this study, a novel and simple isolation of 3,4-DHP was developed either from Leucaena leaves using an ion-exchanged resin or mimosine degraded in high temperature (110°C, 6?h). The inhibition of mimosine on the growth of barnyardgrass was approximately fourfold higher (IC₅₀?=?0.04?mg?g^?1) than that of 3,4-DHP (IC₅₀?=?0.15?mg?g^?1). In general, the antifungal activity of mimosine is much stronger than that of 3,4-DHP, but it differs depending on the kind of fungi. The 1,1-diphyenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of 3,4-DHP, in contrast with the growth inhibitory activity, is about fourfold stronger [EC₅₀?=?2.4?mg?g^?1 gallic acid equivalent (GAE)] than that of mimosine [EC₅₀?=?10.3?mg?g^?1 GAE]. This study is the first to report on the herbicidal, antifungal, and antioxidant activities of 3,4-DHP.     

Isolation and characterization of trichalasin-producing endophytic fungus from <Emphasis Type="BoldItalic">Taxus baccata</Emphasis>

An endophytic fungus (strain T1) isolated from Taxus baccata was studied for the production of metabolites with anticancer and antioxidant activities. This fungus was identified as Diaporthe sp. based on rDNA-internal transcribed spacer (ITS) sequence analysis. The crude extract showed cytotoxic activity against MCF-7 and HeLa cancer cell lines, with IC₅₀ (concentration inhibiting 50% of growth rate) values of 1058?±?44 and 1257?±?80 μg ml^?1, respectively. The scavenging activity of fungal extract increased significantly with increasing concentration [IC₅₀ (concentration required to scavenge 50% of free radicals) 482?±?9 μg ml^?1]. Ultra-high-performance liquid chromatography-quadrupole-time of flight analysis revealed the presence of three trichalasins (trichalasin E, F and H) in the crude extract of T1 which are known to have antitumour and antioxidant activities. These results suggest that Diaporthe sp. has the potential to be used for therapeutic purposes because of its antiproliferative and antioxidant potential and also for the production of cytochalasins.     

Orthogonal Test Design for Optimization of the Extraction of Polysaccharides from Inonotus cuticularis and Their Antioxidant Activities

Medical fungi polysaccharides belong to a very important species of biological macromolecules, which are the basic substances that effectively maintain and ensure the normal operation of biological life activities. However, research on extraction and biological activity of Inonotus cuticularis polysaccharides has never been reported. In this study, the optimum yield of Inonotus cuticularis polysaccharides was determined by the orthogonal experimental design. The highest yield of 3.10±0.06 % was obtained with extraction temperature of 80 °C, extraction time of 150 min, and water to raw material ratio of 30 mL/g and repeated twice. After deproteinization for 5 times, the protein removal rate reached 70.10±1.75 %, and the content of polysaccharides and protein were 46.64 and 0.42 %. Infrared spectrometer indicated that Inonotus cuticularis polysaccharides are typical β‐pyranose with characteristic peaks of polysaccharides. Subsequently, the activities of scavenging free radicals for the deproteinated polysaccharides were studied. When the concentration of Inonotus cuticularis polysaccharides was 0.3 mg/mL, the scavenging activities of the sample on DPPH^., ^.OH, ABTS^.+ and O₂^.? reached 83.67±0.27, 65.21±4.82, 43.45±1.36 and 80.28±2.30 %, respectively, and the reducing power reached 0.46±0.01. The IC₅₀ values scavenging DPPH^., ^.OH, ABTS^.+ and O₂^.? were 0.139±0.13, 0.162±0.14, 0.317±0.30 and 0.121±0.10 mg/mL, respectively. Results showed that Inonotus cuticularis polysaccharides present potential stronger antioxidant activities, especially ^.OH scavenging activity and reducing power. Experimental results could provide research basis of Inonotus cuticularis polysaccharides for further exploitation and utilization.     

Antioxidative iridoid glycosides from the sky flower (Duranta repens Linn)

Phytochemical investigations were performed on the EtOAc-soluble fraction of the whole plant of the sky flower (Duranta repens) which led to the isolation of the iridoid glycosides 1–6. Their structures were elucidated by both 1D and 2D NMR spectroscopic analysis. All the compounds showed potent antioxidative scavenging activity in four different tests, with half maximal inhibitory concentration (IC₅₀) values in the range 0.481–0.719?mM against DPPH radicals, 4.07–17.21 µM for the hydroxyl radical (^?OH) inhibitory activity test, 43.3–97.37 µM in the total reactive oxygen species (ROS) inhibitory activity test, and 3.39–18.94 µM in the peroxynitrite (ONOO^?) scavenging activity test. Duranterectoside A (1) displayed the strongest scavenging potential with IC₅₀ values of (0.481?±?0.06?mM, 4.07?±?0.03, 43.30?±?0.05, 3.39?±?0.02?µM) for the DPPH radicals, ^?OH inhibitory activity test, total ROS inhibitory activity test and the ONOO^? scavenging activity test, respectively.     

Chemical Characterization,Antioxidant Capacity and Antimicrobial Potential of Essential Oil from the Leaves of Baccharis oreophila Malme

This is the first time that composition, antimicrobial potential and antioxidant ability of essential oil from the leaves of Baccharis oreophila are reported. Essential oil was obtained by hydrodistillation and analyzed by GC/MS. Antimicrobial potential was evaluated by diffusion disk and broth microdilution methods. ABTS^.+, DPPH^. and FRAP methods were employed for antioxidant activity evaluation. Essential oil yield was 0.47 %. Sixty‐five compounds were identified, representing 88.53 % of the total essential oil, which showed to be rich in oxygenated (37.88 %) and hydrocarbons sesquiterpenes (34.84 %). The main constituents were khusimone (16.37 %) and spathulenol (16.12 %). Antimicrobial activity was verified against S. aureus (10.33±0.5 mm, MIC: 1250 μg mL^?1) and C. albicans (8.66±0.5 mm, MIC: >2500 μg mL^.1). Antioxidant ability was evidenced by FRAP (4.09 μmol FeSO₄ E mL^?1), ABTS^.+ (1.45 μmol TE mL^?1) and DPPH^. (1.04 μmol TE mL^?1) scavenging capacity. Results showed that this essential oil has interesting biological potential, encouraging further investigations especially in relation to action mechanisms of antimicrobial and antioxidant activity.     

Antioxidant activities in tropical marine macroalgae from the Yucatan Peninsula,Mexico

Extracts from 48 marine macroalgae species (17 Chlorophyta, 8 Phaeophyta and 23 Rhodophyta) from the coasts of Yucatan and Quintana Roo (Mexico) were evaluated for antioxidant activity. The antioxidant activity was measured with the DPPH (2,2-diphenyl-1-picrylhydrasyl) method, and the phenolic content of each extract were also evaluated. All species exhibited a DPPH radical scavenging activity, and three species (Avrainvillea longicaulis, Chondria baileyana and Lobophora variegata) demonstrated great antioxidant potential with very low oxidation index EC₅₀ (1.44 ± 0.01, 2.84 ± 0.07 and 0.32 ± 0.01 mg mL⁻¹, respectively), significantly equivalent to EC₅₀ of some commercial antioxidants such as α-tocopherol, ascorbic acid, BHA and BHT. Moreover, extracts of the most active species exhibited reducing activities, superoxide anion radical scavenging and inhibition of lipid peroxidation. These results suggest that some macroalgae from the Yucatan peninsula have a great antioxidant potential which could be considered for future applications in medicine, food production or cosmetic industry.     

Total phenolic and flavonoid contents and antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome,callus and callus treated with some elicitors

The present study was aimed at determining total phenolic and flavonoid contents and studying the antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome and callus, 6-gingerol and 6-shogaol and callus treated with elicitors. Petroleum ether (PE) and chloroform: methanol (1:1, v/v) (CM) extracts were prepared by maceration. Highest total phenolic content was obtained from the CM extract (60.34?±?0.43?mg gallic acid/g) of rhizome while callus showed lower content detected in the CM extract (33.6?±?0.07?mg gallic acid/g). Flavonoids were only detected in rhizome (CM extract 40.25?±?0.21?mg quercetin/g). Both rhizome extracts exhibited good antioxidant activity with higher activity recorded in PE extract (IC₅₀ value 8.29?±?1.73?μg/mL). Callus extracts revealed lower antioxidant activity (IC₅₀ value 1265.49?±?59.9?μg/mL obtained from CM extract). 6-gingerol and 6-shogaol displayed high antioxidant activity in both assays with IC₅₀ 4.85?+?0.58_DPPH and 5.35?±?0.33_ABTS μg/mL for the former and IC₅₀ 7.61?±?0.81_DPPH and IC₅₀ 7.05?±?0.23_ABTS μg/mL for the latter. Treatment of callus with elicitors showed significant (p?<?0.05) effects in enhancing phenolic content and related antioxidant activity. The highest significant increase in phenolic content (37% and 34%) and antioxidant activity in DPPH assay (34% and 30%) was observed in callus treated with 100?mg/L yeast extract and 50?mg/L salicylic acid respectively. Therefore, studying the effect of the elicitation of ginger cultured tissues in phenolic accumulation would be of immense importance for pharmacological, cosmetic and agronomic industries.     

雪松不同部位中原花青素的含量测定及其清除DPPH自由基的活性

雪松(Cedrus deodara)是松科(Pianaceae)雪松属(Cedrus)树种的泛称,为广泛分布于喜马拉雅山脉的常绿树种,包括雪松(C.deodara)、黎巴嫩雪松(C.libani)、短叶雪松(C.brevifolia)和北非雪松(C.atlantica)等。雪松的针叶药用历史悠久,主要化学成分为黄酮类、苯丙素类、有机酸类、三萜类、甾体类、多糖及针叶胶等,具有抗肿瘤、抗氧化、改善记忆、抗菌及抗病毒等多种功效。为了测定雪松不同部位中原花青素的含量,并考察其清除DPPH自由基活性的能力,该研究以Fe3+离子为催化剂,用正丁醇-盐酸法分别测定雪松松针、花序、小枝、木质部、树皮中原花青素的含量,并对不同部位提取液清除DPPH自由基的能力进行测定。结果表明:松针、花序、木质部、树皮、小枝中原花青素的含量分别为12.93%、12.93%、6.41%、12.00%、3.37%,在质量浓度(以生药计)为0.8 mg·m L-1时,其对DPPH自由基的清除率均达到或接近90%。该研究结果提示雪松各个部位的原花青素含量丰富,其提取液的体外抗氧化活性很高,这为雪松的进一步开发利用提供了很好的参考价值。     

Fatty acid composition and biological activities of Isochrysis galbana T-ISO,Tetraselmis sp. and Scenedesmus sp.: possible application in the pharmaceutical and functional food industries

Organic and water extracts of Isochrysis galbana T-ISO (=Tisochrysis lutea), Tetraselmis sp. and Scenedesmus sp. were evaluated for their antioxidant activity, acetylcholinesterase (AChE) inhibition, cytotoxicity against tumour cell lines, and fatty acids and total phenolic content (TPC). I. galbana T-ISO had the highest TPC (3.18 mg GAE g^?1) and radical scavenging activity, with an IC₅₀ value of 1.9 mg mL^?1 on the acetone extract. The extracts exhibited a higher ability to chelate Fe²⁺ than Cu²⁺, and the maximum Fe²⁺ chelating capacity was observed in the hexane extract of Scenedesmus sp. (IC₅₀=0.73 mg mL^?1) and Scenedesmus sp. (IC₅₀?=?0.73 mg mL^?1). The highest ability to inhibit AChE was observed in the water and ether extracts of Scenedesmus sp., with IC₅₀ values of 0.11 and 0.15 mg mL^?1, respectively, and in the water extract of I. galbana (IC₅₀?=?0.16 mg mL^?1). The acetone extract of I. galbana T-ISO significantly reduced the viability of human hepatic carcinoma HepG2 cells (IC₅₀?=?81.3 μg mL^?1) as compared to the non-tumour murine stromal S17 cell line, and displayed a selectivity index of 3.1 at the highest concentration tested (125 μg mL^?1). All species presented a highly unsaturated fatty acids profile. Results suggest that these microalgae, particularly I. galbana T-ISO, could be a source of biomolecules for the pharmaceutical industry and the production of functional food ingredients and can be considered as an advantageous alternative to several currently produced microalgae.     

Endophytic fungi from Combretum leprosum with potential anticancer and antifungal activity

The recent increase in human diseases and cancers requires new drugs to combat them. Sources have been found in rare microorganisms, those from extreme habitats, and from endophytes. In this study, the biological activity of endophytic fungi associated with the Brazilian medicinal plant Combretum leprosum was assessed. Cytotoxic and antiproliferative effects were evaluated using seven human cancer cells lines (HeLa, ECV304, B16F10, J744, P388, Jurkat and k562). In addition the minimum inhibitory concentration (MIC) against pathogenic human fungal was determined using four Candida species and the filamentous fungi Cryptococcus neoformans and Trichophyton rubrum. A compound from extracts of phylotype Aspergillus oryzae CFE108 exhibited the most significant cytotoxicity effect against histiocytic sarcoma J774 (IC₅₀ of 0.80 μg?mL^?1), leukemia Jurkat (IC₅₀ of 0.89 μg?mL^?1), bladder carcinoma ECV304 (IC₅₀ of 3.08 μg?mL^?1) and cervical cancer HeLa (IC₅₀ of 2.97 μg?mL^?1). The extract from phylotypes Fusarium oxysporum CFE177 displayed antifungal activity and inhibited the growth of Candida glabrata (4 μg?mL^?1) as well as that of C. neoformans and T. rubrum with the lowest MIC being 62.5 μg?mL^?1. In addition, the fractions from A. oryzae CFE108 showed marked morphological activity (rounding up) on endothelial cells (tEnd.1 cells), which is indicative of potential antivascular activity. Our results indicate that the endophytes associated with this medicinal plant may be a source of novel drugs.     

A SPECTROPHOTOMETRIC ASSAY FOR RUBISCO ACTIVITY: APPLICATION TO THE KELP LAMINARIA SACCHARINA AND IMPLICATIONS FOR RADIOMETRIC ASSAYS1

We optimized a spectrophotometric method for measuring ribulose-l,5-bisphosphate carboxylase oxygenase (Rubisco) activity in crude extracts of the kelp Laminaria saccharina Lamour. Activity exhibited a decline during the assays, such that rates determined over a 10-min period were only 70% of activity during the first minute. Activity was significantly enhanced by addition of HCO₃^? to the extraction buffer and was stable for at least 4 h. Highest activities were determined using small extract loads (1–2.5 mg fresh weight·mL^?1 of assay mixture); extract loads of 10 mg·mL^?1caused a 25% decrease in activity. Rubisco activities determined for individual kelp plants using the spectrophotometric method were significantly correlated with total protein and gross photo synthetic capacity (P_max) and were 1.5–2 times higher than P_max. Low Rubisco activities relative to photosynthetic rates reported in many previous studies of macroalgae and microalgae may have resulted at least partly from underestimation of enzyme activity by radiometric assays using relatively large volumes of un-activated crude extract and assay periods longer than 1 min.     

Volatile Composition and Biological Activities of the Leaf Essential Oil from Zanthoxylum limoncello Grown in Oaxaca,México

Zanthoxylum limoncello is a native plant from southern Mexico which is used as a timber source, condiment and as a traditional medicine. Herein, we report on the volatile content of the leaf essential oil and its biological activities. The annual essential oils (2015–2018) contained volatile organic compounds which exhibited a moderate growth inhibitory activity against H. pylori ATCC 53504 (MIC 121.4–139.7 μg mL^?1), 26695 (MIC 85.5–94.9 μg mL^?1) and J99 (MIC 94.7–110.4 μg mL^?1). These hydrodistillates contained 2‐undecanone (31.6–36.8 %; MIC 185.3–199.2 μg mL^?1) and 2‐undecenal (25.1–35.7 %; MIC 144.8–111.3 μg mL^?1) as the most abundant compounds which were partially involved in the anti‐H. pylori activity. The human ornithine decarboxylase enzyme (ODC1), which shows increased activity in several cancer types, was non‐competitively inhibited (V_max 2.7>0.8 K_cat s^?1) by the essential oil of Z. limoncello as well as by 2‐undecanone and 2‐undecenal in accordance to in vitro kinetic studies. In silico calculations strongly suggest that the carbonyl group of these oxygenated hydrocarbons interacts with both Asn319 and Ala39 at the subunit A of ODC1. Considering that Ala39 is located close to Asn44, a crucial amino acid of the ODC's allosteric site, the non‐competitive inhibition of the enzyme by 2‐undecanone and 2‐undecenal is endorsed. Finally, the essential oil of Z. limoncello and its main volatiles showed a significant (p<0.01) and prolonged repellent effect against Aedes aegypti.     

Essential Oil Compositions and Antibacterial and Antioxidant Activities of Five Lavandula stoechas Cultivars Grown in Thailand

The essential oils of five Lavandula stoechas cultivars grown in Thailand were characterized for their volatile compounds using GC‐FID and GC/MS methods as well as screened for antibacterial and antioxidant activities. Dried aerial parts, including flowers and stems from each cultivar, were subjected to hydrodistillation for 4 h. The essential oil yields were 0.18 %–0.82 % w/w. Of the 95 compounds detected and identified, 1,8‐cineole, fenchone, and camphor were considered the major compounds. Essential oil from each cultivar demonstrated different patterns of antibacterial activity and a variety of antioxidant properties. The highest antibacterial activity, MIC=0.39 mg mL^?1, was observed from the essential oil of L. stoechas ‘major’ (against Klebsiella pneumoniae and Salmonella typhimurium) and the essential oil of L. stoechas ‘white lavender’ (against S. typhimurium). The essential oil of L. stoechas×viridis ‘St. Brelade’ possessed the highest antioxidant capacity, as determined by the DPPH and ABTS assays (IC₅₀ of 67.65 and 89.26 mg mL^?1, respectively). The results indicated that some of these essential oils could be used as key ingredients in lavender oil products in Thailand to increase their therapeutic efficacy, depending on their intended application.     

LC-HRMS Profiling and Phenolic Content,Cholinesterase, and Antioxidant Activities of Terminalia citrina

Terminalia citrina (T. citrina) belongs to the Combretaceae family and is included in the class of medicinal plants in tropical countries such as Bangladesh, Myanmar, and India. The antioxidant activities of lyophilized water (WTE) and alcohol extracts (ETE) of T. citrina fruits, their phenolic content by LC-HRMS, and their effects on cholinesterases (ChEs; AChE, acetylcholinesterase, and BChE, butyrylcholinesterase) were investigated. Especially ten different analytical methods were applied to determine the antioxidant capacity. Compared with similar studies for natural products in the literature, it was determined that both WTE and ETE exhibited strong antioxidant capacity. Syringe and ellagic acids were higher than other acids in ETE and WTE. IC₅₀ values for ETE and WTE in DPPH radical and ABTS⋅⁺ scavenging activities were calculated as 1.69–1.68 μg mL⁻¹ and 6.79–5.78 μg mL⁻¹, respectively. The results of the biological investigations showed that ETE and WTE had an inhibition effect against ChEs, with IC₅₀ values of 94.87 and 130.90 mg mL⁻¹ for AChE and 262.55 and 279.70 mg mL⁻¹ for BChE, respectively. These findings indicate that with the prominence of herbal treatments, T. citrina plant may guide the literature in treating Alzheimer's Disease, preventing oxidative damage, and mitochondrial dysfunction.