High-value Bioactive Compounds Research Articles

Wood Bark-Based Films as Electrical Insulators with Ultralow Dielectric Constant and Loss Factor.

Dielectric polymers, particularly thermally stable synthetic types, play a crucial role in capacitors, circuit boards, insulators, and high-frequency devices. However, they also contribute significantly to electronic waste, making up approximately 20% of the 74.7 million metric tons of e-waste generated each year. Unfortunately, less than 18% of this waste is properly recycled, posing serious risks to human health and the environment. To address these challenges, we present a circular approach to fabricating biobased dielectric structures with ultralow dielectric constant and dielectric loss factor. Our method utilizes forestry residues derived from birch bark, after the extraction of high-value bioactive compounds. Specifically, we process the thermally stable, lignin-rich fibers in the residual bark through partial dissolution and cross-linking to produce "birch dielectric (BD)" films. These films exhibit exceptional dielectric properties, with dielectric constant (Dk) and loss factor (Df) values as low as ∼1.8 and ∼0.002, respectively, outperforming or matching the requirements of modern electrical insulators, including advanced polymer blends based on polyimides. In addition to their functional performance, BD films demonstrate remarkable mechanical and thermal stability, photothermal conversion capabilities, strength retention after cycling, and biodegradability. These findings, supported by experimental data and simulation studies of intermolecular interactions, highlight the potential of BD films as a sustainable and efficient alternative to conventional dielectric materials.

The family Thermoactinomycetaceae: an emerging microbial resource with high application value

In recent years, interest has increased in the use of microorganisms to obtain additional valuable resources for green and sustainable development. Preliminary functional analyses have indicated that members of the family Thermoactinomycetaceae have good application potential for the production of novel specific enzymes, high-value bioactive compounds, novel secondary metabolites and the promotion of efficient biomass conversion. Therefore, they can be considered a new class of microbial resources with potentially high value. However, the lack of culture and culture-independent techniques coupled with the uncertain taxonomic status of the family Thermoactinomycetaceae, has made exploring these potential applications challenging. This paper reviews the distribution characteristics and functional properties of the family Thermoactinomycetaceae, providing a detailed interpretation of the potential application value of this group and proposing a set of systematic resource development strategies based on a combination of culture-dependent and culture-independent strategies to exploit its potential for resource applications.

A Novel Process for Oleacein Production from Olive Leaves Using Freeze Drying Methodology.

The abundant yet underutilized olive leaves, a renewable by-product of olive cultivation, offer untapped potential for producing high-value bioactive compounds, notably oleacein. Existing extraction methods are often inefficient, yielding low quantities of oleacein due to enzymatic degradation of its precursor, oleuropein, during conventional processing and storage. This study aimed to overcome these limitations by exploring a novel methodology based on freeze-drying, to facilitate the in situ enzymatic biotransformation of oleuropein into oleacein directly within the plant matrix. Olive leaves were subjected to three drying methods-ambient air drying, microwave drying, and freeze-drying-and their phenolic profiles were analyzed. The findings demonstrated that freeze drying uniquely promotes the selective activation of β-glucosidase and esterase enzymes while simultaneously inhibiting oxidative enzymes, such as polyphenol oxidase and peroxidase, resulting in significantly enriched oleacein content. This process eliminates the need for extensive post-extraction transformations, providing a cost-effective, scalable, and sustainable approach to oleacein production. The proposed methodology aligns with circular economy principles and holds substantial potential for applications in pharmaceuticals, nutraceuticals, and functional food industries.

Antioxidant Bio-Compounds from Chestnut Waste: A Value-Adding and Food Sustainability Strategy.

In an era of escalating environmental challenges, converting organic residues into high-value bioactive compounds provides a sustainable way to reduce waste and enhance resource efficiency. This study explores the potential of the circular bioeconomy through the valorization of agricultural byproducts, with a focus on the antioxidant properties of specific chestnut burr cultivars. Currently, over one-third of food production is wasted, contributing to both humanitarian and environmental crises. Through circular bioeconomy, we can transform biological waste into valuable products for use in fields like food innovation and sustainability. The antioxidant effects of three chestnut cultivars, Bastarda Rossa, Cecio, and Marroni, were assessed through in vitro assays, highlighting their potential to combat oxidative stress-an important factor for health-related applications. The characterization of the three cultivars showed the major presence of ellagic acid and gallic acid in the extract, renowned for their antioxidant activity. In vitro assays evaluated the phenolic and flavonoid content, as well as the antioxidant activity of the three extracts, confirming the cultivar Cecio as the richest in these bioactive compounds and the most performative in antioxidant assays. In vitro antioxidant and oxidative stress recovery assays on SaOS-2, fibroblast, and chondrocyte cell lines displayed a strong antioxidant activity. Furthermore, the cytotoxicity assay demonstrated the safety of all three extracts in the tested human cell lines. In silico docking simulations further validated the biological relevance of these compounds by predicting strong hydrophobic and polar interactions with oxidative stress-related protein targets. Overall, this study demonstrates the antioxidant properties of chestnut byproducts. The findings contribute to the development of functional foods, nutraceuticals, and other applications, underscoring the role of chestnut cultivars in advancing circular bioeconomy practices.

Microalgal Bioeconomy: A Green Economy Approach Towards Achieving Sustainable Development Goals

This article delves into the role of microalgae in advancing a green economy, thereby contributing to the attainment of Sustainable Development Goals (SDGs). Microalgae, as sustainable resources, offer multifaceted benefits across various sectors, including aquaculture, agriculture, food and feed, pharmaceuticals, cosmetics, wastewater treatment, and carbon sequestration. This review highlights the versatility of microalgae in producing biofuels, high-value bioactive compounds, and bioremediation processes. It examines the technical viability and environmental sustainability of microalgae cultivation, emphasizing its low carbon footprint and resource efficiency. This article also explores the integration of microalgae into existing industrial processes, illustrating their potential to mitigate climate change, promote biodiversity, and enhance resource circularity. Challenges such as scalability, cost-effectiveness, and regulatory frameworks are discussed alongside the prospects for technological innovations and policy support to bolster the microalgae industry. By harnessing the potential of microalgae, this article underscores a pathway towards a more sustainable and greener future, aligning with the global agenda for sustainable development.

Antioxidant activity of Micractinium sp. (Chlorophyta) extracts against H2O2 induced oxidative stress in human breast adenocarcinoma cells

In response to the growing demand for high-value bioactive compounds, microalgae cultivation has gained a significant acceleration in recent years. Among these compounds, antioxidants have emerged as essential constituents in the food, pharmaceutical, and cosmetics industries. This study focuses on Micractinium sp. ME05, a green microalgal strain previously isolated from hot springs flora in our laboratory. Micractinium sp. cells were extracted using six different solvents, and their antioxidant capacity, as well as total phenolic, flavonoid, and carotenoid contents were evaluated. The methanolic extracts demonstrated the highest antioxidant capacity, measuring 7.72 and 93.80 µmol trolox equivalents g−1 dry weight (DW) according to the DPPH and FRAP assays, respectively. To further characterize the biochemical profile, reverse phase high-performance chromatography (RP-HPLC) was employed to quantify twelve different phenolics, including rutin, gallic acid, benzoic acid, cinnamic acid, and β-carotene, in the microalgal extracts. Notably, the acetone extracts of Micractinium sp. grown mixotrophically contained a high amount of gallic acid (469.21 ± 159.74 µg g−1 DW), while 4-hydroxy benzoic acid (403.93 ± 20.98 µg g−1 DW) was the main phenolic compound in the methanolic extracts under heterotrophic cultivation. Moreover, extracts from Micractinium sp. exhibited remarkable cytoprotective activity by effectively inhibiting hydrogen peroxide-induced oxidative stress and cell death in human breast adenocarcinoma (MCF-7) cells. In conclusion, with its diverse biochemical composition and adaptability to different growth regimens, Micractinium sp. emerges as a robust candidate for mass cultivation in nutraceutical and food applications.

Heterologous biosynthesis of betanin triggers metabolic reprogramming in tobacco

Engineering of a specialized metabolic pathway in plants is a promising approach to produce high-value bioactive compounds to address the challenges of climate change and population growth. Understanding the interaction between the heterologous pathway and the native metabolic network of the host plant is crucial for optimizing the engineered system and maximizing the yield of the target compound. In this study, we performed transcriptomic, metabolomic and metagenomic analysis of tobacco (Nicotiana tabacum) plants engineered to produce betanin, an alkaloid pigment that is found in Caryophyllaceae plants. Our data reveals that, in a dose-dependent manor, the biosynthesis of betanin promotes carbohydrate metabolism and represses nitrogen metabolism in the leaf, but enhances nitrogen assimilation and metabolism in the root. By supplying nitrate or ammonium, the accumulation of betanin increased by 1.5–3.8-fold in leaves and roots of the transgenic plants, confirming the pivotal role of nitrogen in betanin production. In addition, the rhizosphere microbial community is reshaped to reduce denitrification and increase respiration and oxidation, assistant to suppress nitrogen loss. Our analysis not only provides a framework for evaluating the pleiotropic effects of an engineered metabolic pathway on the host plant, but also facilitates the development of novel strategies to balance the heterologous process and the native metabolic network for the high-yield and nutrient-efficient production of bioactive compounds in plants.

Green Extraction of Bioactive Compounds from Apple Pomace from the Cider Industry.

The cider-making industry in Asturias generates between 9000 and 12,000 tons of apple pomace per year. This by-product, the remains of the apple pressing, and made up of peel, flesh, seeds and stems, is a valuable material, containing substantial amounts of antioxidant compounds associated with healthy properties. Polyphenols such as dihydrochalcones and quercetin glycosides, and triterpenic acids, among which ursolic acid is a major compound, are the main antioxidant families described in apple pomace. The simultaneous recovery of those families has been accomplished by low frequency ultrasound-assisted extraction. Working extraction conditions were optimised by response surface methodology (RSM): time, 5.1 min; extractant composition, 68% ethanol in water; solid/liquid ratio, 1/75 and ultrasonic wave amplitude, 90%. This procedure was further applied to analyse those components in the whole apple pomace (WAP), apple peel (AP) and apple flesh (AF). On average, dry WAP contained almost 1300 µg/g of flavonols, 1200 µg/g of dihydrochalcones and 4200 µg/g of ursolic acid. These figures increased in the apple peel to, respectively 2500, 1400 and 8500 µg/g dry matter. Two linear multivariate regression models allowed the antioxidant activity of apple by-products to be predicted on the basis of their bioactive composition. The results derived from this study confirm the potential of industrial cider apple pomace as a source of high-value bioactive compounds, and the feasibility of the ultrasound-assisted extraction technique to recover those components in a simple and efficient way.

Assessment of chemical composition of blackberries and mulberries from Covilhã region, Portugal

Berries have gained popularity recently due to the health benefits associated with their bioactive compounds. This work aimed to evaluate the physicochemical characteristics, colour, phytochemicals content and mineral content of three common berries, two types of blackberries (Rubus fruticosus and R. ulmifolius) and one mulberry (Morus nigra), collected in the Covilhã region, Portugal. R. fruticosus presented the greatest length, weight, moisture, firmness and darker colour, while R. ulmifolius showed the greatest width. On the other hand, M. nigra showed the highest ash content (2.49±0.40 %). A total of 20 phenolics were identified and quantified by chromatographic techniques. Using ICP-MS and FAAS, 13 essential and 14 non-essential elements were quantified. Additionally, 54 volatiles were detected through HS-SPME/GC-MS, several compounds were herein reported for the first time in these berries. Our results show that these berries contain a high concentration of high-value bioactive compounds, significantly influencing their nutritional value, aroma and appeal to consumers, providing data to make it possible to choose more attractive and superior blackberry and mulberry varieties that meet consumer demands.

Characterization of natural compounds derived from diatom C. gracilis as potential therapeutic agents: An in-silico networking and docking study

Marine diatom Chaetoceros gracilis have been known as the key player regulating the nutritional content of aquaculture species. Being able to synthesize an array of high value bioactive compounds like amino acids, lipids, terpenoids and polysaccharides, it also serves as potential therapeutic and nutraceutical agent. This in silico-based study elucidates the interactive association of different compounds, proteins and pathways of the diatom C. gracilis through an integrated network pharmacology and molecular docking approach. According to the Network analysis of the 41 compounds detected, saturated hydrocarbons, diterpenoids and phenolic compounds scored the highest degree (score > 140). These compounds were further coded for approximately 349 protein targets and almost 490 different pathways. HSP90AA1, STAT3, HIF1A, MTOR, ESR1, PIK3CA, MAPK1 and PTGS2 secured highest degree of protein-protein interaction according to STRING database. The gene enrichment analysis further revealed that these proteins were closely associated with metabolic pathways like Pathways in cancer, neuroactive ligand-receptor interaction, calcium and cAMP signaling pathway, PI3K-Akt signaling pathway, Alzheimer's disease and pathways of neurodegeneration which played an instrumental role in the metabolism of diseases and disorders like cancers of breast, prostrate, and liver, schizophrenia and other mental and hypertensive disorders. Furthermore, the molecular docking and toxicity assessment of a few novel compounds was done with mTOR and HSP90AA1 which revealed promising and stable interactions. Thus, this study provides the first in silico insight outlining the anti-cancerous and neuroprotective potential of novel bioactive compounds derived from marine diatom C.gracilis.

The complete chloroplast genome sequence of red raspberry (Rubus idaeus L.) and phylogenetic analysis

Red raspberries, Rubus idaeus L. 1753 are famous fruits which possess high value bioactive compounds. In this study, we report the complete chloroplast genome of R. idaeus, it displayed a typical quadripartite structure with 155687 bp in length. The genome encodes 127 genes including 79 protein coding genes, 8 rRNA genes and 40 tRNA genes, the overall GC content is 37.2%. Phylogenetic analysis revealed a close relationship between R. idaeus and R. sachalinensis in Section Malaehobatus.

Green Approaches for the Extraction of Banana Peel Phenolics Using Deep Eutectic Solvents.

Banana peels, comprising about 35% of the fruit's weight, are often discarded, posing environmental and economic issues. This research focuses on recycling banana peel waste by optimizing advanced extraction techniques, specifically microwave-assisted (MAE) and ultrasound-assisted extraction (UAE), for the isolation of phenolic compounds. A choline chloride-based deep eutectic solvent (DES) with glycerol in a 1:3 ratio with a water content of 30% (w/w) was compared to 30% ethanol. Parameters, including sample-to-solvent ratio (SSR), extraction time, and temperature for MAE or amplitude for UAE, were varied. Extracts were analyzed for hydroxycinnamic acid (HCA) and flavonoid content, and antioxidant activity using FRAP and ABTS assays. DES outperformed ethanol, with HCA content ranging from 180.80 to 765.92 mg/100 g and flavonoid content from 96.70 to 531.08 mg/100 g, accompanied by higher antioxidant activity. Optimal MAE conditions with DES were an SSR of 1:50, a temperature of 60 °C, and a time of 10 min, whereas an SSR of 1:60, time of 5 min, and 75% amplitude were optimal for UAE. The polyphenolic profile of optimized extracts comprised 19 individual compounds belonging to the class of flavonols, flavan-3-ols, and phenolic acids. This study concluded that DESs, with their superior extraction efficiency and environmental benefits, are promising solvents for the extraction of high-value bioactive compounds from banana peels and offer significant potential for the food and pharmaceutical industries.

Harnessing the Potential of Harpin Proteins: Elicitation Strategies for Enhanced Secondary Metabolite Accumulation in Grapevine Callus Cultures

Grapes and grape products are rich in secondary metabolites such as phenolic compounds and anthocyanins, which have antioxidant properties. These compounds possess health-promoting attributes, including cardioprotective, antimicrobial, and anticancer effects. In recent years, biotechnological methods have been employed to produce high quantities and purity of secondary metabolites under in vitro conditions, aiming to elucidate their complex functions and optimize production methods. However, the potential effects of harpin proteins on the accumulation of secondary compounds in callus cultures have not been investigated thus far. Harpin proteins, encoded by the hrp gene clusters in Gram-negative phytopathogens, are known to trigger defense responses in various plant species by promoting the accumulation of secondary compounds. These findings suggest that harpin proteins may have the potential to enhance secondary metabolite accumulation in callus cultures. This study therefore investigated the potential of applying different concentrations of harpin protein (0, 0.1, 1, 10, and 100 ppm) to increase secondary metabolite production in calluses derived from petioles of the “Horoz Karası” grape cultivar. Our findings revealed that 1 and 10 ppm harpin treatments resulted in the highest anthocyanin accumulations, with 17.21 and 16.57 CV/g, respectively, representing 1.95- and 1.87-fold increases compared to control treatments, respectively. Total phenolic content peaked at 0.39 mg GAE g−1 FW with the 1 ppm harpin treatment, representing a 4.33-fold increase over the control. Total flavonol levels reached their highest levels at 0.027 mg CE g−1 FW with 1 and 10 ppm harpin concentrations, resulting in a 2.25-fold increase compared to the control. The highest averages for total flavonol content were recorded at 0.024 and 0.021 mg RE g−1 FW with 1 and 10 ppm harpin concentrations, respectively, representing 1.5- and 1.3-fold increases over the control. Principal component analysis (PCA) corroborated the results obtained from the heatmap analysis, indicating that harpin applications at 1 and 10 ppm were the most effective concentration range for maximizing secondary metabolite synthesis, while very low or high concentrations diminished these effects. These findings offered valuable insights for optimizing the production of high-value bioactive compounds, which can be utilized in various fields such as medicine, pharmaceuticals, food, and cosmetics. These results are expected to serve as a valuable reference for elucidating the mechanisms by which harpin proteins, rarely used in vitro, exert their effects on grapevine calluses, contributing to the literature in this domain.

Microbial allies: exploring fungal endophytes for biosynthesis of terpenoid indole alkaloids.

Terpenoid indole alkaloids (TIAs) are natural compounds found in medicinal plants that exhibit various therapeutic activities, such as antimicrobial, anti-inflammatory, antioxidant, anti-diabetic, anti-helminthic, and anti-tumor properties. However, the production of these alkaloids in plants is limited, and there is a high demand for them due to the increasing incidence of cancer cases. To address this research gap, researchers have focused on optimizing culture media, eliciting metabolic pathways, overexpressing genes, and searching for potential sources of TIAs in organisms other than plants. The insufficient number of essential genes and enzymes in the biosynthesis pathway is the reason behind the limited production of TIAs. As the field of natural product discovery from biological species continues to grow, endophytes are being investigated more and more as potential sources of bioactive metabolites with a variety of chemical structures. Endophytes are microorganisms (fungi, bacteria, archaea, and actinomycetes), that exert a significant influence on the metabolic pathways of both the host plants and the endophytic cells. Bio-prospection of fungal endophytes has shown the discovery of novel, high-value bioactive compounds of commercial significance. The discovery of therapeutically significant secondary metabolites has been made easier by endophytic entities' abundant but understudied diversity. It has been observed that fungal endophytes have better intermediate processing ability due to cellular compartmentation. This paper focuses on fungal endophytes and their metabolic ability to produce complex TIAs, recent advancements in this area, and addressing the limitations and future perspectives related to TIA production.

Black soldier fly (Hermetia illucens L.): A potential small mighty giant in the field of cosmeceuticals.

Natural products are widely used in the pharmaceutical and cosmetics industries due to their high-value bioactive compounds, which make for "greener" and more environmentally friendly ingredients. These natural compounds are also considered a safer alternative to antibiotics, which may result in antibiotic resistance as well as unfavorable side effects. The development of cosmeceuticals, which combine the cosmetic and pharmaceutical fields to create skincare products with therapeutic value, has increased the demand for unique natural resources. The objective of this review is to discuss the biological properties of extracts derived from larvae of the black soldier fly (BSF; Hermetia illucens), the appropriate extraction methods, and the potential of this insect as a novel active ingredient in the formulation of new cosmeceutical products. This review also addresses the biological actions of compounds originating from the BSF, and the possible association between the diets of BSF larvae and their subsequent bioactive composition. A literature search was conducted using PubMed and Google Scholar to identify and evaluate the various biological properties of the BSF. One such natural resource that may be useful in the cosmeceutical field is the BSF, a versatile insect with numerous potential applications due to its nutrient content and scavenging behavior. Previous research has also shown that the BSF has several biological properties, including antimicrobial, antioxidant, anti-inflammatory, and wound healing effects. Given the range of biological activities and metabolites possessed by the BSF, this insect may have the cosmeceutical potential to treat a number of skin pathologies.

Durian (Durio zibethinus L.): Nutritional Composition, Pharmacological Implications, Value-Added Products, and Omics-Based Investigations

Durian (Durio zibethinus L.), a tropical fruit celebrated in Southeast Asia for its distinct flavor, is the focus of this comprehensive review. The fruit’s pulp is rich in high-value bioactive compounds, including gamma-glutamylcysteine, a precursor to the essential antioxidant glutathione. With durian cultivation gaining prominence in Southeast Asia due to its economic potential through cultivar enhancement, an in-depth examination of durian-related research becomes crucial. This review explores the health benefits of durian, analyzing the nutritional compositions and bioactive compounds present in the pulp, peel, and seed. It also underscores durian-based food products and the potential for valorizing durian waste. This review encapsulates the significant advancements made in omics-based research, aimed at deciphering the molecular complexities of durian fruit post-harvest ripening and the metabolic shifts impacting its sensory attributes. It is the first to summarize studies across genome, transcriptome, and metabolome levels. Future research should prioritize the development of molecular markers to accelerate the breeding of elite cultivars with preferred traits. It also proposes the exploration of durian waste valorization, including underexplored parts like flowers and leaves for their bioactive compounds, to promote a sustainable bioeconomy. Finally, it suggests the development of innovative durian products catering to the tastes of health-conscious consumers.

Extraction of 4-hydroxy benzoic acid from potato processing industrial waste

Abstract Due to the substantial volume of waste produced and the potential for high-value bioactive compounds to be extracted from potato peel, the valorization of industrial waste of potato processing industry is the subject of this research. The study presents an innovative technique for efficient extraction of 4-hydroxybenzoic acid (P-HBA), a valuable bioactive molecule, from potato peel extract by utilizing molecularly imprinted chitosan beads (MICB). The MICB was synthesized using environmentally benign cross-linkers such as Tetraethyl orthosilicate (TEOS), Sodium triphosphate (STPP), while P-HBA was is used as a template. The MICB was investigated using FTIR, SEM, and EDAX. Adsorption studies were conducted to optimize parameters like adsorbent dose, solution concentration, time and pH. A recovery rate of 95.07 % is recorded from a synthetic P-HBA solution when measured by HPLC while from the actual potato processing industrial effluent the same is 40 %. The adsorption capacity of MICB is 67.5 mg g−1 and specific binding capacity is 20.62 mg g−1 which remained unchanged for six consecutive cycle reuse. This is the first study to report uptake of a bioactive molecule from actual potato processing industry waste.

Establishment of feijoa (Acca sellowiana) callus and cell suspension cultures and identification of arctigenin - a high value bioactive compound.

Feijoa (Acca sellowiana (O. Berg.) Burret), also known as pineapple guava, is a member of the Myrtaceae family and is well known for its fruit. Chemical profiling of the different tissues of the feijoa plant has shown that they generate an array of useful bioactive compounds which have health benefits such as significant antioxidant activities. In this study, an in vitro culture system has been developed, which could be explored to extract high-value bioactive compounds from feijoa. Feijoa tissue culture was initiated by the induction of callus from floral buds. Sections of floral buds were plated on MS medium supplemented with 2,4-D and BAP at 2.0mg/L and 0.2mg/L concentrations, respectively. Cell suspension cultures of feijoa were established using a liquid MS medium with different concentrations of 2,4-D and BAP and cultured on a rotary shaker. The growth of the cell suspension was evaluated with different parameters such as different carbohydrate sources, concentration of MS media, and inoculum density. When the cell suspensions were treated with different concentrations of MeJA at different time points, phytochemicals UPLC - QTOF MS analysis identified extractables of interest. The main compounds identified were secondary metabolites (flavonoids and flavonoid-glucosides) and plant hormones. These compounds are of interest for their potential use in therapeutics or skin and personal care products. This report investigates essential methodology parameters for establishing cell suspension cultures from feijoa floral buds, which could be used to generate in vitro biomass to produce high-value bioactive compounds. This is the first study reporting the identification of arctigenin from feijoa, a high-value compound whose pharmaceutical properties, including anti-tumour, anti-inflammatory and anti-colitis effects, have been widely reported. The ability of feijoa cell cultures to produce such high-value bioactive compounds is extremely promising for its use in pharmaceuticals, cosmeceuticals and nutraceuticals applications.

Enhancement of dieckol extraction yield from Ecklonia cava through optimization of major variables in generally recognized as safe solvent-based process

Ecklonia cava (EC), an edible brown macroalga abundant in intertidal areas of East Asia (Korea, Japan, and China), contains high-value bioactive compounds such as dieckol, which has antifungal, anti-inflammatory, antitumor, and antihyperlipidemic activities. However, no studies have been reported on the utilization of EC as a biorefinery feedstock, and the design of a more economical and high-yield process is required for the utilization of dieckol for the human healthcare industry. In this study, we designed a bioprocess for the high-yield recovery of dieckol from EC in a generally recognized as safe (GRAS) solvent to facilitate its application in the food and healthcare industries. Preliminary studies identified ethanol as an efficient solvent with the highest dieckol extraction yield (2.9 mg/g biomass). In order to maximize the recovery of dieckol from EC, the major extraction variables (solvent concentration, reaction temperature, and reaction time) were optimized based on statistical methods. Based on the predictive model, the numerical optimization determined that the solution with the highest dieckol content per weight of extract (62.6 vol% ethanol concentration, 54.2°C temperature, 13.2 min) was the optimal extraction condition. Under the determined conditions, the dieckol yield from EC achieved 6.4 mg dieckol/g EC (95.5% agreement with the predicted value). The designed process offers several advantages, including improving the utilization feasibility of EC, utilizing GRAS solvents with potential human applications, short extraction time (13.2 min), maximized process yield, and the highest dieckol recovery compared to previous reports.

Freshwater microalgae Desmodesmus brasiliensis, Mychonastes timauensis, and Mychonastes ovahimbae as excellent microalgae candidates for sustainable live feeds with high-value bioactive compounds

Exploring high-value natural antioxidants from microalgae as feasible live feeds in aquaculture is receiving worldwide attention. Yet, limited microalgae species have been entirely studied for aquaculture production, especially freshwater microalgae for their antioxidant properties. Three freshwater microalgae, Desmodesmus brasiliensis (PHG C02), Mychonastes timauensis (PHG E02), and Mychonastes ovahimbae (PHG F04) were screened for their phytochemicals (chlorophylls a and b, total carotenoids content, TCC; total flavonoids content, TFC, and total phenolic content, TPC), enzymatic antioxidants (Superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX and guaiacol peroxidase, GPX) as well as non-enzymatic antioxidants (ascorbic acid, AA and α-tocopherol, α-TOC) at the early stationary phase. The results unveiled that the phytochemical and antioxidant activities responded diversely in the selected species. D. brasiliensis achieved the highest Chl a, Chl b, and TCC contents, whereas M. timauensis recorded the highest TFC and TPC contents. Significant differences in AA and α-TOC contents were observed in M. timauensis and D. brasiliensis for non-enzymatic antioxidants, respectively. In contrast, SOD and GPX reached the maximum activities in M. ovahimbae. A significant upsurge of CAT was spotted in D. brasiliensis. However, APX activity was elevated in M. timauensis and M. ovahimbae. D. brasiliensis attained most of the notably highest phytochemical and antioxidant activities, suggesting that D. brasiliensis has the potential for sustainable live feeds with high-value bioactive compounds.