Dominant Compounds Research Articles

Specialized seed dispersal in Neotropical Vanilla reveals fruit unpalatability to omnivores.

Flowering plants are essentially sessile organisms that disperse their genes through pollination, expanding their areas of occurrence through seed dispersal. In orchids, seed dispersal is commonly mediated by air currents. Conversely, members of several genera have evolved seeds adapted to endozoochory. This is the case for Vanilla, the most economically important genus in the orchid family. The role of indehiscent fruits in the attraction and rewarding of Vanilla seed dispersers was investigated based on field observations, analysis of fragrances, reward substances, and investigation of seed viability through the digestive tract. Indehiscent Vanilla fruits are consumed exclusively by herbivores, i.e. agoutis. Besides providing nutritional rewards, the fruits are rich in polyphenols that are unpalatable to omnivores. The most dominant compound in fruits is attractive only to agoutis. This is the first study showing synzoochory in Orchidaceae and specificity of seed dispersal in orchids. Indehiscent fruits may have evolved early in Neotropical Vanilla in response to selection pressures mediated by large herbivores as the genus emerged ca. 34 Mya in South America, concomitantly with megafauna diversification in the Oligocene. Extinction of the megafauna during the Pleistocene has left agoutis as inheritors of seed dispersal in species with large fleshy fruits. Apart from the effects on omnivores, this study shows that indehiscent fruits of V. chamissonis are consumed exclusively by agoutis, providing the first evidence of target mutualism in orchid seed dispersal.

Study of Hyssop Essential Oil from Southeastern Serbia.

The aim of the present study was a chemical, microbiological and statistics analysis of Hyssopus officinalis L. subsp. aristatus (Godr.) Nyman essential oil during different stages of development from three natural populations of plant collected in southeastern Serbia. In addition, using statistical tools, we also tried to explain the effect of dominant components' content on antimicrobial activity. Oxygenated monoterpenes were the most abundant compound class in the H. officinalis oil during examined phenological stages (27.32-92.25 %). The four most abundant essential oil components are eucalyptol, cis-pinocamphone, β-pinene and β-ocimene. H. officinalis essential oils demonstrated minimum inhibitory concentrations and minimum microbicidal concentrations values from 2.4 to 160 mg/mL. Maximum antimicrobial activity, in total, was recorded in November, after the flowering stage. The percentage of dominant compounds of essential oils, eucalyptol, and cis-pinocamphone, affects essential oils' antibacterial activity. The essential oil with most closely matched research criteria was extracted from a plant in Kravlje village.

Insights on Microplastic Contamination from Municipal and Textile Industry Effluents and Their Removal Using a Cellulose-Based Approach.

The rampant use of plastics, with the potential to degrade into insidious microplastics (MPs), poses a significant threat by contaminating aquatic environments. In the present study, we delved into the analysis of effluents from textile industries, a recognized major source of MPs contamination. Data were further discussed and compared with a municipal wastewater treatment plant (WWTP) effluent. All effluent samples were collected at the final stage of treatment in their respective WWTP. Laser diffraction spectroscopy was used to evaluate MP dimensions, while optical and fluorescence microscopies were used for morphology analysis and the identification of predominant plastic types, respectively. Electrophoresis was employed to unravel the prevalence of negative surface charge on these plastic microparticles. The analysis revealed that polyethylene terephthalate (PET) and polyamide were the dominant compounds in textile effluents, with PET being predominant in municipal WWTP effluents. Surprisingly, despite the municipal WWTP exhibiting higher efficiency in MP removal (ca. 71% compared to ca. 55% in textile industries), it contributed more to overall pollution. A novel bio-based flocculant, a cationic cellulose derivative derived from wood wastes, was developed as a proof-of-concept for MP flocculation. The novel derivatives were found to efficiently flocculate PET MPs, thus allowing their facile removal from aqueous media, and reducing the threat of MP contamination from effluents discharged from WWTPs.

Evaluation of Antioxidant Properties of Wild and Cultivated Blueberry Leaves and Their Phenolic Compound

Aim of study: This study aimed to investigate the antioxidant activity and polyphenol and flavonoid content of blueberry leaves, which could have positive effects on human health. Area of study: The research was conducted in three cities of Türkiye's Karadeniz region, where blueberry cultivation is prevalent: Giresun, Trabzon, and Rize. Material and method: In this study, 29 blueberry leaves (27 cultivated and two wild) were selected as sample materials. The total phenolic content (Folin-Ciocalteu method), total flavonoid content (aluminum (III) chloride method), and total antioxidant capacity (DPPH and FRAP) of the samples were analyzed. Phenolic characterization was performed using HPLC. Main results: The total phenolic content varied between 8.36 and 121.61 mg GAE/g, whereas the total flavonoid content ranged from 0.91 to 3.07 mg QE/g. The results revealed that blueberry leaves had high antioxidant activity and contained considerable amounts of polyphenols and flavonoids. Chlorogenic acid was identified as the dominant compound in all leaves samples. Research highlights: These findings indicate that blueberry leaves could be a valuable source of antioxidants in the food and cosmetic industries, comparable to the fruit itself.

Phytochemical Profile and Antioxidant and Protective Activities of Various Types of Extracts from Hyssopus officinalis L. and Grindelia robusta Nutt. Herb Grown in Poland.

The available literature indicates that Hyssopus officinalis and Grindelia robusta are raw materials with great potential for use in prevention and therapy. Therefore, the aims of this study were to assess the phytochemical profile and antioxidant and cytoprotective properties of extracts prepared using various solvents, additionally taking into account different methods of drying the plant material. Hydrodistilled oil was analysed by GC-MS. The chemical composition of the extracts was estimated by spectrophotometry and the HPLC-DAD method. Antioxidant activity was evaluated using DPPH and FRAP and measuring the intracellular level of ROS. Alamar Blue and Neutral Red tests were used to assess the cytotoxicity of the extracts on skin cells - keratinocytes and fibroblasts. The major components of hyssop essential oil were cis- (44.9%) and trans- (18.2%) pinocamphone, while borneol (16.1%), and α-pinene (12.0%) were predominant in grindelia essential oil. Flavonoids were dominant in the extracts (water:ethanol, water:methanol, and water: glycerol) from hot-air dried hyssop herb, while phenolic acids were the predominant compounds in the grindelia herb extracts. The water:ethanol hyssop extract had the highest total content of flavonoids (42.26 mg CE/mL), among which isoquercitrin and rutin were present in the highest quantities (32.61 mg/mL and 21.47 mg/mL, respectively). In the case of grindelia, the highest total phenolic acid content (26.24 mg CAE/mL) was recorded in the water:ethanol extract, and the dominant compounds among them were 1,5-dicaffeoylquinic and chlorogenic acid (10.85 and 6.39 mg/mL, respectively). The water:ethanol extract from both plants also exhibited the highest antioxidant activity in the DPPH and FRAP tests (79.19% and 1.39 mmol/L, respectively, for grindelia and 67.61% and 1.04 mmol/L for hyssop) and was most effective at reducing the level of ROS in cells. In addition, water:ethanol extracts may have a positive impact on the viability of skin cells in vitro. Water:ethanol extracts from H. officinalis and G. robusta herb are promising sources of active compounds and may find application as natural materials with valuable biological properties, which require further in vitro and in vivo testing.

A comparative analysis on impact of drying methods on metabolite composition in broccoli microgreens

This study evaluated the effect of three preparation methods—fresh, microwave drying, and air fryer drying—on the bioactive compounds in broccoli microgreens. Microgreens, harvested 12 days after sowing, were processed and analyzed using LC-MS/MS. The data analysis involved ANOVA, Tukey's HSD, heatmaps, PCA, hierarchical clustering, and KEGG pathway analysis. While ANOVA showed no significant differences (P > 0.05) in the total quantity of compounds between the methods, the presence or absence of specific compounds varied significantly (P < 0.05) between the Fresh, Microwaved, and Air Fried Samples. Heatmap analysis indicated a moderate positive correlation between the Fresh Sample and both processed samples. PCA and KMeans clustering revealed distinct differences in compound concentrations across the methods, with box plots highlighting variability within clusters. The dominant compounds varied, with the Fresh Sample exhibiting the highest mean antioxidant and anticancer activity. All methods primarily affected metabolic and secondary biosynthesis pathways. This study underscores the importance of preparation methods in influencing the nutritional and bioactive compound composition of broccoli microgreens, with implications for food science and metabolic research. Optimizing these techniques could further enhance their health benefits.

Antioxidant properties of lemon essential oils: a meta-analysis of plant parts, extraction methods, dominant compounds, and antioxidant assay categories

Recent studies have explored the antioxidant properties of lemon essential oil (LEO), taking considering factors like plant part, extraction methods, and antioxidant assay. However, due to varied results and limited precision in individual studies, our meta-analysis aims to offer a comprehensive understanding across different experiments, irrespective of location or time. Out of 109 scientific articles published between 1947 and 2024, only 28 successfully validated their data on differences in antioxidant capacity and IC50, using weighted averages of Hedges’ d in meta-analysis. A meta-analysis revealed several key findings: (i) lemon leaf and peel extracts have higher IC50 compared to controls, whereas whole plant extracts show lower values (p < 0.001); (ii) the maceration preserves antioxidant properties better than hydro-distillation and Soxhlet extraction (p < 0.001); (iii) LEO require higher concentrations to achieve comparable free radical inhibition as the standard controls such as AsA, BHT, and quercetin, suggesting lower antioxidant efficiency. This was supported by IC50 result, which showed no significant difference between LEO and other compounds like thymol, Thymus vulgaris EO, and Citrus aurantium EO. However, compared to AsA, BHT, limonene, and trolox, the inhibition efficacy was significantly lower (p < 0.01). These findings consistently demonstrated significant antioxidant activity across multiple assays, including ABTS, β-carotene bleaching, DPPH, and FRAP (p < 0.01). Notably, the predominant components of LEO including α-linoleic acid, D-limonene, limonene, L-limonene, neryl acetate, sabinene, and Z-citral, which demonstrate significant potency as antioxidant agent (p < 0.01). Specifically, limonene and Z-citral make substantial contributions to its antioxidant capacity (p < 0.01). Despite variations in purity among LEO extractions, there is potential for future enhancement through nanoemulsion. In conclusion, LEO show promise as an alternative antioxidant, with emphasis to selecting samples based on leaves or peels and employing maceration extractions for various antioxidant assays. Active components rich in terpenoids, such as limonene and Z-citral, are particularly noteworthy.Graphical

Per- and polyfluoroalkyl substances (PFAS) in floor dust from different indoor environments in Australia: Levels, variation, and human exposure risks

Per-and polyfluoroalkyl substances (PFAS) have been a global concern in relation to human exposure. Dust has been proven to be an important source of human exposure to many groups of organic pollutants, however, no study so far has systematically evaluated human exposure to PFAS depending on time spent in different indoor environments i.e., houses, offices and public transport vehicles. Archived dust samples were collected from residential houses (n = 38), offices (n = 15), and public transport vehicles (n = 12) in Australia to assess human exposures to PFAS via dust ingestion and dermal contact. Amongst the 19 target analytes, 14 compounds were detected in >50% of the samples. Significantly higher PFAS concentrations were found in dust samples collected from offices with mean ± SD of 400 ± 810 ng/g than houses (170 ± 350 ng/g) and public transport vehicles (39 ± 33 ng/g). Composition patterns of PFAS varied among indoor environments with Perfluorohexanoic acid (PFHxA) (median 2.5 ng/g dust) and perfluorooctanoic acid (PFOA) (median 5.7 ng/g) were the most prevalent compounds detected (DF = 100%). PFOA was the dominant PFAS compound in both offices (median 11 ng/g) and houses (median 5.8 ng/g). Perfluorododecanoic acid (PFDoA) (median 3.6 ng/g) was found to be the most abundant compounds in public transport vehicles. Considering the time spent in indoor environments, relatively higher estimated daily intakes (EDIs) were identified in offices than in houses and public transport vehicles. EDIs for PFOA and perfluorooctane sulfonic acid (PFOS) for adults and toddlers were well below the acceptable levels of 20 ng/kg/day proposed by U.S Environmental Protection Agency (USEPA) and Food Standard Australia and New Zealand (USEPA, 2016; FSANZ et al. (2016)), suggesting low or negligible exposure pathways via dust ingestion and dermal contact.

Clostridium carboxidivorans and Rhodosporidium toruloides as a platform for the valorization of carbon dioxide to microbial oils

There is growing scientific interest in oleaginous yeasts producing microbial oils as precursors of biofuels and potential substitutes for fossil fuels. Due to the high cost of substrates commonly metabolized by yeasts, volatile fatty acids (VFAs) are gaining interest as alternative cheap and sustainable carbon sources, which can be obtained from solid, liquid and gas pollutants. In this research, Rhodosporidium toruloides was proven to be able to accumulate microbial oils from VFAs obtained from the fermentation of syngas by Clostridium carboxidivorans. Using CO2 and CO as carbon sources from the syngas mixture and H2 as energy source, this acetogen produced, via the Wood-Ljungdahl pathway, a mixture of acetic, butyric and caproic acids. It was first revealed that R. toruloides exhibited minimal inhibition at concentrations below 12 g/L when exposed to a mixture of VFAs, which included acetic, butyric and even hexanoic acids. The yeast was then grown on the culture medium derived from the acetogenic fermentation of syngas. Between the two yeast strains tested of the same species, R. toruloides DSM 4444 reached a total VFAs consumption of 69.1 g/L, supplied by successive additions of acids to the reactor, yielding a maximum lipid content of 29.7% w/w cell. The lipid profile obtained in this case, in terms of abundance followed the order C18:1 > C16:0 ≥ C18:0 > C18:2>others; in which the dominant compound (C18:1), represented approximately 50% of the total. This research opens new possibilities in the cultivation of oleaginous yeasts for the production of biofuels and bioproducts from C1 gases.

Antimicrobial Potential of Calotropis gigantea Leaf Against Klebsiella pneumoniae in Ventilator-Associated Pneumonia

Calotropis gigantea or biduri has traditional medicinal properties. However, the effect of C. gigantea leaves in assisting the function of antibiotic-resistant ventilator-associated pneumonia (VAP), particularly caused by Klebsiella pneumoniae, has not been evaluated. The purpose of this study was to identify the active compounds of C. gigantea leaf extracts growing in the coastal area of Alue Naga, Banda Aceh, Indonesia, and assess its antimicrobial potential in preventing microbial resistance. C. gigantea leaves were extracted using three different solvents: ethanol, ethyl acetate, and n-hexane. The three extracts of C. gigantea leaves were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and the active compounds of C. gigantea were identified using gas chromatography-mass spectroscopy (GC-MS). The dominant bioactive compounds of the C. gigantea extract were enrolled for molecular docking analysis. The results of this study showed that the inhibitory concentration 50% (IC50) of the ethanol extract had a higher antioxidant activity (IC50 value of 3.3 ppm) than the ethyl acetate (IC50 value of 22.97 ppm) and n-hexane (IC50 value of 32.9 ppm). Bioactive compound identification using GC-MS from the three extracts showed similar dominant compounds, which were α-amyrin and lup-20(29)-en-3-ol, and these compounds belonged to the class of triterpenoid derivative compounds. Molecular docking analysis showed that α-amyrin (-9.6 Kcal/mol), β-amyrin (-9.6 Kcal/mol), and epilupeol (-9.2 Kcal/mol) in C. gigantea leaves had higher binding free energy values compared to cefixime (-8.7 Kcal/mol). Thus, it could be concluded that C. gigantea leaf extract is assumed to have great potential as an antimicrobial agent and in preventing microbial resistance, particularly in cases of VAP caused by Klebsiella pneumoniae. Doi: 10.28991/HEF-2024-05-03-010 Full Text: PDF

Dietary polyphenols reduced the allergenicity of β-lactoglobulin via non-covalent interactions: a study on the structure-allergenicity relationship

Studies showed that complexation of polyphenols with milk allergens reduced their immunogenic potential. However, the relationship between structures of polyphenols and their hypoallergenic effects on milk allergens in association with physiological and conformational changes of the complexes remain unclear. In this study, polyphenols from eight botanical sources were extracted to prepare non-covalent complexes with β-lactoglobulin (β-LG), a major allergen in milk. The dominant phenolic compounds bound to β-LG with a diminished allergenicity were identified to investigate their respective role on the structural and allergenic properties of β-LG. Extracts from Vaccinium fruits and black soybeans were found to have great inhibitory effects on the IgE- and IgG-binding abilities of β-LG. Among the fourteen structure-related phenolic compounds, flavonoids and tannins with larger MWs and multi-hydroxyl substituents, notably rutin, EGCG, and ellagitannins were more potent to elicit changes on the conformational structures of β-LG to decrease the allergenicity of complexed β-LG. Correlation analysis further demonstrated that a destabilized secondary structure and protein depolymerization caused by polyphenol-binding were closely related to the allergenicity property of formed complexes. This study provides insights into the understanding of structure-allergenicity relationship of β-LG-polyphenol interactions and would benefit the development of polyphenol-fortified matrices with hypoallergenic potential.

Aromatic Herbs of the Lamiaceae Family as Functional Ingredients in Wheat Tortilla

The rationale for this research is the investigation of the potential health benefits as well as the antibacterial and antifungal properties of selected aromatic plants from the Lamiaceae family, which may lead to the development of improved functional foods. The present study investigated the effects of incorporating dried aromatic plants Thymus vulgaris, Thymus serpyllum, Thymus × citriodorus, Origanum vulgare and Rosmarinus officinalis at a concentration of 1% in refined wheat flour and wholemeal flour on the production of functional tortillas. Sensory analysis was employed to identify the optimal 1% addition, with the objective of achieving a favorable flavor and aroma profile. It was hypothesized that this addition would affect water activity, moisture, texture, color, antioxidant content and phenolic content, thereby enhancing the tortillas as a source of bioactive compounds. The results indicated that the type of flour used had a significant impact on the water activity of the tortillas, with wholemeal flour resulting in higher water activity than refined flour. The water activity ranged between 0.735 and 0.821, while the water content remained relatively stable. The water activity in whole-grain tortillas was significantly higher than that of refined flour tortillas, with a value exceeding 0.8, which makes them susceptible to mold growth and the production of mycotoxins. The sensory evaluations indicated that the enriched refined flour tortillas with common thyme (Thymus vulgaris), lemon thyme (Thymus × citriodorus) and rosemary (Rosmarinus officinalis) were rated highly; a similar result was observed for the whole-grain tortillas enriched with wild thyme (Thymus serpyllum) and lemon thyme. The whole-grain tortillas with rosemary were rated the highest of all the tortillas. The addition of aromatic plants increased the phenolic content and the antioxidant potential, depending on the flour type and the plant used. The addition of wild thyme and rosemary resulted in a significant increase in the phenolic content of wheat tortillas, while all enriched whole-grain tortillas exhibited a higher phenolic content than the control samples. The highest phenolic content in whole-grain tortillas was found in those fortified with rosemary, oregano and wild thyme. The highest antioxidant content was recorded in tortillas prepared with rosemary, irrespective of whether the flour used was refined or wholemeal. Fourteen phenolic compounds were tentatively identified in aromatic plants tested. The main phenolic compounds in Origanum vulgare were flavonoids. Rosmarinic acid was the dominant phenolic compound in rosemary and all thyme species, reaching the highest level in rosemary. Such high levels of rosmarinic acid may be responsible for the high antioxidant and total phenolic contents observed in rosemary extracts and also in tortillas when this plant is included in the recipe. The results of this study indicate that selected aromatic plants, particularly rosemary, have the potential to be utilized as functional ingredients in bakery products. By incorporating dried aromatic plants from the Lamiaceae family into wheat flour tortillas, food manufacturers can create products that not only taste better but also provide added health benefits. The use of selected herbs can improve the nutritional profile of tortillas by increasing antioxidant properties and, due to the properties of herbs, extend the shelf life of the product.

Phytochemical Analysis, Biological Activities, and Docking of Phenolics from Shoot Cultures of Hypericum perforatum L. Transformed by Agrobacterium rhizogenes.

Hypericum perforatum transformed shoot lines (TSL) regenerated from corresponding hairy roots and non-transformed shoots (NTS) were comparatively evaluated for their phenolic compound contents and in vitro inhibitory capacity against target enzymes (monoamine oxidase-A, cholinesterases, tyrosinase, α-amylase, α-glucosidase, lipase, and cholesterol esterase). Molecular docking was conducted to assess the contribution of dominant phenolic compounds to the enzyme-inhibitory properties of TSL samples. The TSL extracts represent a rich source of chlorogenic acid, epicatechin and procyanidins, quercetin aglycone and glycosides, anthocyanins, naphthodianthrones, acyl-phloroglucinols, and xanthones. Concerning in vitro bioactivity assays, TSL displayed significantly higher acetylcholinesterase, tyrosinase, α-amylase, pancreatic lipase, and cholesterol esterase inhibitory properties compared to NTS, implying their neuroprotective, antidiabetic, and antiobesity potential. The docking data revealed that pseudohypericin, hyperforin, cadensin G, epicatechin, and chlorogenic acid are superior inhibitors of selected enzymes, exhibiting the lowest binding energy of ligand-receptor complexes. Present data indicate that H. perforatum transformed shoots might be recognized as an excellent biotechnological system for producing phenolic compounds with multiple health benefits.

Identifying the dominant compound events and their impacts on vegetation growth in China

Terrestrial vegetation plays a vital role in global carbon recycling, but it is also affected by compound events (CEs); however, little is known about the impacts of these CEs on vegetation in terms of their occurrence and magnitude. Using meteorological observations and vegetation indices (leaf area index (LAI), gross primary productivity (GPP), and net primary productivity (NPP)) from 1981 to 2020, we explored the occurrence of 13 CEs types and identified the dominant CEs types across different eco-geographical regions of China, and quantified the response of various vegetation types to dominant CEs. We found that CEs of extreme hot-dry, extreme hot-dry-high fire weather, dry-high fire weather, and high fire weather-strong wind were the dominant types of compound events during the growing season in China, and their hazards increased at a rate of >0.1HI/10a during 1981–2020. We further detected that more than 60% of the total vegetation areas showed a strong negative correlation with compound extreme hot-dry-high fire weather-strong wind events, which was relatively higher than compound extreme hot-dry events. The response of vegetation to compound events varied at the national scale, which was related to the vegetation type, dominant compound event type, and local natural conditions. This study highlights the benefits of a multivariate perspective on compound events and reveals the regional differences in the response of vegetation to compound events, which can provide initial guidance to assess the regional compound event risk of vegetation against the background of carbon neutrality by 2060.

Sapwood and nikhra heartwood volatiles of two Combretaceae species traditionally used in Sudanese cosmetology and therapy

The smoke from Combretum hartmannianum and Terminalia laxiflora sapwood and fermented heartwood (nikhra) are used in body smoke baths and homemade skincare products in Sudan, which are believed to have various health benefits. In this study, the volatiles of sapwood and nikhra were collected using two extraction techniques: a Mono-TrapTM sampling technique (at low temperature) and a smoke trapping system (at high temperature). After GC-MS analysis, the chromatogram of each sample revealed numerous peaks. The detected peaks were identified using the DIST08 mass spectral library database, resulting in known and unknown compounds. The results showed that 1,2,4,5-tetrachloro-3,6-dimethoxybenzene was the major compound in the Mono-Trap and smoke extracts from nikhra samples of C. hartmannianum and T. laxiflora. In contrast, the dominant compounds in the Mono-Trap extracts of C. hartmannianum and T. laxiflora sapwoods were acetonyldimethylcarbinol and cadina-1(10),4-diene, respectively. The largest peaks in the chromatograms of the sapwood smoke extracts of both species corresponded to unknown compounds. Some of the detected compounds are known for their aromatic and pharmaceutical properties. Identifying these aromatic compounds in nikhra and not in sapwood might prove the traditional Sudanese beliefs, and it could potentially improve the manufacturing of health products.

Chemical Composition and Phytotoxic Activity of Mentha vagans Boriss. Essential Oil.

This study explored the composition of essential oil (EO) and the first phytotoxic screening of EO obtained from the stems and leaves of Mentha vagans Boriss (MVEO) via hydro-distillation technique. The EO ingredients were detected through Gas Chromatography-Mass Spectrometry (GC-MS). GC-MS analysis revealed that MVEO contained 49 constituents, constituting 93.95 % of the total oil. Among MVEO constituents, dihydrocarvone was observed as the dominant constituent (24.14 %), followed by D-carvone (16.28 %) and piperitone (18.14 %). The phytotoxic effects of MVEO and its dominant compounds were examined against Amaranthus retroflexus, Lolium perenne, and Poa annua. Significant inhibition was observed by MVEO in comparison with the major constituents and their mixture, suppressing the seedling growth of tested species at the lowest dosage (0.01 mg/mL); in general, seedling growth of all tested species was markedly inhibited when applied concentration of the EO and its constituents reached 0.05 mg/mL. Our results also indicated that constituents other than the dominant compounds of MVEO possessed considerable phytotoxic effects because the EO's activity was stronger than its major constituents and their mixture. Thus, additional studies are required to investigate MVEO and its constituents and commercialize them as environment-friendly bio-herbicides.

Comparative Analysis of Phytochemical Composition and Antioxidant Properties of Smilax china Rhizome from Different Regions

This study aimed to investigate variations in the phytochemical compound contents and antioxidant potential of the ethanol rhizome extracts of Smilax china L., belonging to the Liliaceae family, from different parts of Korea, namely Uiwang (Mt. Gamnamugol), Gyeonggi Province (SC1); Geochang, Gyeongnam Province (SC2); Yeongwol, Gangwon Province (SC3); and Chungju, Chungbuk Province (SC4). The phenolic and flavonoid contents, radical scavenging activity, and proximate composition of the ethanol extracts from the rhizome samples were determined. The total polyphenol content (TPC) of the extracts ranged between 13.6 and 67.5 mg tannic acid equivalent/g. TPC analysis showed that TPC was higher in SC2 than in SC3, SC4, or SC1. Among the rhizome samples, the SC3 rhizomes had the highest total flavonoid content (TFC) (5.2 mg quercetin equivalents/g). Additionally, SC2 showed the highest radical scavenging activity against DPPH and ABTS+ radicals. Chemical characterization using UPLC/UV revealed that the extracts contained compounds such as apiin, kaempferol-3-rutinoside, and chlorogenic acid. Specifically, in SC2, chlorogenic acid was the dominant compound, which supported the levels observed in the UPLC/UV and HPLC/ELSD investigations. Dioscin, another phytochemical, was detected in SC2, SC3, and SC4, indicating the diversity of compounds among the rhizome extracts. Variations in the phytochemical content and antioxidant activity were observed in the extracts from the different regions, underlining the role of geographical variation in the functional characteristics of S. china. The observed differences could have important implications for the medicinal use of S. china extracts in applications such as anti-inflammatory treatments, diabetes management, and potential anticancer therapies. This study underscores the critical need to consider geographical origin when sourcing and utilizing S. china for therapeutic purposes, as it may significantly impact its bioactive profile and efficacy.

Maximizing Bioactive Compound Extraction from Mandarin (Citrus reticulata) Peels through Green Pretreatment Techniques

This study explored the use of mandarin peels as an important source of health-promoting compounds by utilizing green methods (i.e., pulsed electric field and ultrasound-assisted extraction), along with conventional stirring. The impact of several extraction parameters, such as extraction duration, temperature, and solvent composition, on the recovery of bioactive compounds was evaluated through a response surface methodology. To identify the most effective conditions for all assays, a partial least-squares analysis was implemented. It was revealed that a combination of the above techniques was optimal at 80 °C for 30 min, with 75% v/v of ethanol in water as the extraction solvent. The concentration of bioactive compounds in the optimum extract had a total polyphenol content of 18.69 mg of gallic acid equivalents (GAE) per gram of dry weight (dw), and an ascorbic acid concentration of 18.25 mg/g dw. However, correlation analyses revealed a rather negative relationship between these bioactive compounds. The chromatographic analysis of optimum extracts supported this result by quantifying 20.53 mg/g dw of total individual polyphenols, with hesperidin being the dominant compound (13.98 mg/g dw). The antioxidant assays, including ferric-reducing antioxidant power and DPPH• inhibition activity, were measured at 123.21 and 65.12 μmol of ascorbic acid equivalents (AAE) per gram of dw, respectively. This research enhances the valorization of mandarin peels as a renewable source of bioactive compounds, providing the opportunity to generate high-added-value products from food waste in the food and pharmaceutical sectors.

Insights into the physiology, biochemistry and ecological significance of the red seaweed Tricleocarpa fragilis in the Andaman Sea

The present study focused on the physiological and biochemical aspects of Tricleocarpa fragilis, red seaweed belonging to the phylum Rhodophyta, along the South Andaman coast, with particular attention given to its symbiotic relationships with associated flora and fauna. The physicochemical parameters of the seawater at the sampling station, such as its temperature, pH, and salinity, were meticulously analyzed to determine the optimal harvesting period for T. fragilis. Seaweeds attach to rocks, dead corals, and shells in shallow areas exposed to moderate wave action because of its habitat preferences. Temporal variations in biomass production were estimated, revealing the highest peak in March, which was correlated with optimal seawater conditions, including a temperature of 34 ± 1.1 °C, a pH of 8 ± 0.1, and a salinity of 32 ± 0.8 psu. GC‒MS analysis revealed n-hexadecanoic acid as the dominant compound among the 36 peaks, with major bioactive compounds identified as fatty acids, diterpenes, phenolic compounds, and hydrocarbons. This research not only enhances our understanding of ecological dynamics but also provides valuable insights into the intricate biochemical processes of T. fragilis. The established antimicrobial potential and characterization of bioactive compounds from T. fragilis lay a foundation for possible applications in the pharmaceutical industry and other industries.

Precipitation contributes to alleviating pollution of rubber-derived chemicals in receiving watersheds: Combining confluent stormwater runoff from different functional areas

The release of rubber-derived chemicals (RDCs) in road surface runoff has received significant attention. Urban surface runoff is often the confluence of stormwater runoff from specific areas. However, the impact of precipitation on RDCs contamination in confluent stormwater runoff and receiving watersheds remains poorly understood. Herein, we investigated the profiles of RDCs and their transformation products in confluent stormwater runoff and receiving rivers affected by precipitation events. The results showed that 34 RDCs are ubiquitously present in confluent stormwater runoff and surface water, with mean concentrations of 1.03–2749 and 0.28–436 ng/L, respectively. The most dominant target compounds in each category were N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), 6PPD-quinone, 2-benzothiazolol, and 1,3-diphenylguanidine. Total RDCs concentrations in confluent stormwater runoff decreased spatially from industrial areas to business districts to college towns. A significant decrease in RDCs levels in surface water after rainfall was observed (P < 0.01), indicating that precipitation contributes to alleviating RDCs pollution in receiving watersheds. To our knowledge, this is the first report of N,N'-ditolyl-p-phenylenediamine quinone (DTPD-Q) levels in surface waters in China. The annual mass load of ∑RDCs reached 72,818 kg/y in confluent stormwater runoff, while 38,799 kg/y in surface water. The monitoring of confluent stormwater runoff is an efficient measure for predicting contamination loads from RDCs in rivers. Risk assessment suggested that most RDCs posed at least medium risks to aquatic organisms, especially 6PPD-quinone. The findings help to understand the environmental fate and risks of RDCs in the confluent stormwater runoff and receiving environments after precipitation events.