Tunicates as Sources of High-Quality Nutrients and Bioactive Compounds for Food/Feed and Pharmaceutical Applications: A Review.

Tunicates are widely distributed worldwide and are recognized as abundant marine bioresources with many potential applications. In this review, state-of-the-art studies on chemical composition analyses of various tunicate species were summarized; these studies confirmed that tunicates contain nutrients similar to fish (such as abundant cellulose, protein, and ω-3 fatty acid (FA)-rich lipids), indicating their practical and feasible uses for food or animal feed exploration. However, the presence of certain toxic elements should be evaluated in terms of safety. Moreover, recent studies on bioactive substances extracted from tunicates (such as toxins, sphingomyelins, and tunichromes) were analyzed, and their biological properties were comprehensively reviewed, including antimicrobial, anticancer, antioxidant, antidiabetic, and anti-inflammatory activities. In addition, some insights and prospects for the future exploration of tunicates are provided which are expected to guide their further application in the food, animal feed, and pharmaceutical industries. This review is critical to providing a new pathway for converting the common pollution issues of hydroponic nutrients into valuable marine bioresources.

Collagens for surimi gel fortification: Type-dependent effects and the difference between type I and type II.

Surimi products have unsatisfactory gel properties. Hence, this study evaluates the effect of collagen-adding on surimi gel properties and provides the first observation results regarding collagen type influence. With higher water solubility and more charged amino acids than type II, collagen type I intertwines with surimi myofibrillar proteins better to induce higher exposure of protein functional domains, more sufficient conformational changes of myosin and greater formation of chemical forces among proteins. These enhancements accelerate the gelation rate, leading to a well-stabilized surimi gel. The collagen I-containing surimi gels show more compact structures with uniformly distributed smaller pores than those containing collagen II, thereby providing the final products with higher water holding capacity and better textural profiles. As such, the surimi gel fortification performance of collagen I and the well-elucidated collagen-myofibrillar protein interaction mechanism will guide the further exploitation of collagen as an effective additive in the food industry.

Wound Healing, Antimicrobial and Antioxidant Properties of Clinacanthus nutans (Burm.f.) Lindau and Strobilanthes crispus (L.) Blume Extracts.

Clinacanthus nutans is known to be an anticancer and antiviral agent, and Strobilanthes crispus has proven to be an antidiuretic and antidiabetic agent. However, there is a high possibility that these plants possess multiple beneficial properties, such as antimicrobial and wound healing properties. This study aims to assess the wound healing, antioxidant, and antimicrobial properties of Clinacanthus nutans and Strobilanthes crispus. The Clinacanthus nutans and Strobilanthes crispus leaves were dried, ground, and extracted with ethanol, acetone, and chloroform through cold maceration. In a modified scratch assay with co-incubation of skin fibroblast and Methicillin-resistant Staphylococcus aureus, Clinacanthus nutans and Strobilanthes crispus extracts were assessed for their wound healing potential, and the antimicrobial activities of Clinacanthus nutans and Strobilanthes crispus extracts were performed on a panel of Gram-positive and Gram-negative bacteria on Mueller-Hinton agar based on a disc diffusion assay. To assess for antioxidant potential, 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and total flavonoid assays were conducted. In the modified scratch assay, Clinacanthus nutans extracts aided in the wound healing activity while in the presence of MRSA, and Strobilanthes crispus extracts were superior in antimicrobial and wound healing activities. In addition, Strobilanthes crispus extracts were superior to Clinacanthus nutans extracts against Pseudomonas aeruginosa on Mueller-Hinton agar. Acetone-extracted Clinacanthus nutans contained the highest level of antioxidant in comparison with other Clinacanthus nutans extracts.

Stretchable AgX (X = Se, Te) for Efficient Thermoelectrics and Photovoltaics.

Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag2S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional AgxSe1-x and AgxTe1-x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P212121-Ag8Se4 and P21/c-Ag8Te4 structures. Recently reported metastable AgTe3 was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/nmm-Ag4Se2 and C2-Ag8Te4 phases. Orthorhombic Ag8Se4 crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag4Se2 monolayer. Interestingly, metallic P21/c-Ag8Te4 changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young's modulus (E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11-28%), relatively high n(0) (1.59-1.93), and sizable α(ω) (104-105 cm-1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag-Se was found to rise from approximately 0.15-0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies.

Aporphine alkaloids from Piper erecticaule and acetylcholinesterase inhibitory activity / Alcaloides de aporfina obtenida de Piper erecticaule y actividad inhibitoria de la acetilcolinesterasa

Chemical constituents and biological activities of the aerial parts of Piper erecticaule C.DC. have been studied for the first time. Fractionation and purification of the extracts afforded aristolactam AII (1), aristolactam BII (2), piperolactam A (3), piperolactam C (4), piperolactam D (5), together with terpenoids of ß-sitosterol, ß-sitostenone, taraxerol, and lupeol. The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that compounds 1 and 3 showed strong AChE inhibitory effects with the percentage inhibition of 75.8% and 74.8%, respectively.

Se estudiaron por primera vez los constituyentes químicos y actividad biológica de las partes aéreas de Piper erecticaule C.DC. El fraccionamiento y la purificación de los extractos proporcionaron aristolactama AII (1), aristolactama BII (2), piperolactama A (3), piperolactama C (4), piperolactama D (5), junto con terpenoides de ß-sitosterol, ß-sitostenona, taraxerol, y el lupeol. Las estructuras de estos compuestos se obtuvieron mediante el análisis de sus datos espectroscópicos, así como mediante la comparación con datos ya informados. La actividad inhibidora de la acetilcolinesterasa reveló que los compuestos 1 y 3 mostraron un potente efecto inhibidor de la AChE con un porcentaje de inhibición del 75.8% y 74.8%, respectivamente.

Total Phenolic Content and Antioxidant and Antibacterial Activities of Pereskia bleo.

Different solvent extracts of Pereskia bleo leaves were evaluated for total phenolic content (TPC) and antioxidant activities based on the Folin-Ciocalteu test and DPPH scavenging activities. The antibacterial activities against four bacteria, namely, Gram-positive bacteria: Streptococcus pyogenes ATCC 19615 (SP) and Staphylococcus aureus ATCC 29737 (SA) and Gram-negative bacteria: Escherichia coli ATCC 10536 (EC) and Pseudomonas aeruginosa ATCC 9027 (PA), were also performed based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. The findings demonstrated that both the methanolic and chloroform extracts displayed strong activities against SA, SP, EC, and PA while the hexane extract demonstrated the weakest activities towards all the four bacteria. The methanolic extract also exhibited higher TPC and possessed higher antioxidant activity with the IC50 value 33.83 µg/mL compared to the chloroform and hexane extracts. As such, the methanolic extract has a higher ability to scavenge free radical compared to other extracts. Due to the interesting result, activities are shown by the methanolic and chloroform crude extracts of P. bleo; hence, the study has been extended to the isolation of bioactive compounds to uncover its great potential as a natural source for antibacterial and antioxidant agents.

Anticholinesterase and Anti-inflammatory Constituents from Beilschmiedia pulverulenta Kosterm

Phytochemical investigation from the stem bark of Beilschmiedia pulverulenta resulted in the isolation of five lignans, (+)-yangambin (1), (+)-sesartemin (2), (+)-excelsin (3), (+)-sesamin (4), and (+)-syringaresinol (5), together with lupeol (6), lupenone (7), β-sitosterol (8), and β-sitostenone (9). Their structures were established by the analysis of their spectroscopic (1D and 2D NMR) and spectrometric (MS) data, as well as by comparison with those reported in the literature. The isolated lignans were tested for their anticholinesterase (AChE: acetylcholine esterase and BChE: butyryl cholineesterase) and anti-inflammatory (COX-2: cyclooxygenase-2 and LOX: lipoxygenase) activities. All the isolated lignans (1 – 5) exhibited significant inhibition activities in AChE/BChE and COX-2/LOX assays with IC50 values ranging from 168.8 – 504.2 µM and 21.0 – 59.4 µM, respectively.

Chemical composition of Piper stylosum Miq. and Piper ribesioides Wall.essential oils, and their antioxidant, antimicrobial and tyrosinaseinhibition activities / Composición química de los aceites esenciales de Piper stylosum Miq. y Piper ribosoides Wall. y sus actividadesantioxidantes, antimicrobiana y de inhibición de la tirosinasa

Chemical compositions of P. stylosum and P. ribesioides essential oils, and their antioxidant, antimicrobial and tyrosinase inhibition activities were determined. GC and GC–MS analysis of essential oils from leaves and stems of P. stylosum resulted in the identification of 50 (89.2 percent) and 45 (88.8 percent) components, respectively. The major components were aromadendrene (leaves 26.6 percent; stems 18.8 percent), sabinene (leaves 13.8 percent; stems 6.7 percent) and beta-caryophyllene (leaves 11.5 percent; stems 17.9 percent). A total of 60 (87.0 percent) and 39 (82.9 percent) components were identified from leaves and stems of P. ribesioides, respectively. The most abundant components were beta-caryophyllene (leaves 20.0 percent; stems 14.4 percent), camphene (leaves 16.3 percent; stems 12.3 percent) and delta-cadinene (leaves 4.4 percent; stems 7.8 percent). Antioxidant activity using DPPH and total phenolic content were tested for essential oils. However, the essential oils showed low antioxidant activity and phenolic content, compared to BHT. Studies of tyrosinase inhibition showed that the essential oils of P. ribesioides leaves had the highest inhibition (30.0 percent), although were lower than the control (kojic acid 81.8 percent). The evaluation of antimicrobial activities revealed that P. ribesioides essential oils showed strong activity against Bacillus cereus and Staphylococcus aureus, both with MIC value 62.5 micrograms/mL.

Se determinaron las composiciones químicas, las actividades antioxidante y antimicrobiana, y el contenido total de fenoles de los aceites esenciales de P. stylosum y P. ribesioides. El análisis GC y GC-MS de los aceites esenciaales de hojas y tallos de P. stylosum permitió la identificación de 50 (89.2 por ciento) y 45 (88.8 por ciento) de components, respectivamente. Los principales componentes fueron aromadendreno (hojas 26.6 por ciento; tallos 18.8 por ciento), sabineno (hojas 13.8 por ciento; tallos 6.7 por ciento) y beta-cariofileno (hoja 11.5 por ciento; tallo 17.9 por ciento). Se identificaron 60 (87.0 por ciento) y 39 (82.9 por ciento) components en los aceites esenciales de hojas y tallos de P. ribesioides. Los componentes más abundantes fueron beta-cariofileno (hojas 20.0 por ciento; tallos 14.4 por ciento), canfeno (hojas 16.3 por ciento; tallos 12.3 por ciento) y delta-cadineno (hojas 4.4 por ciento; tallos 7.8 por ciento). Los aceites esenciales se ensayaron para determinar sus actividades antioxidantes con DPPH y el contenido de fenoles totales. Para los aceites esenciales obtenidos se determinaron valores bajos en la actividad antioxidante con DPPH y el contenido total de fenoles, en comparación con BHT. Sin embargo, los ensayos de inhibición de tirosinasa most raron que el aceite esencial de las hojas de P. ribesioides presento la mayor inhibición (30.0 por ciento), aunque mas baja que el compuesto control (Àcido Kójico, 81.8 por ciento). Para el aceite esencial de P. ribesioides se determinó una MIC 62.5 mg/mL contra Bacillus cereus y Staphylococcus aureus.

The pyranoxanthone inophyllin A induces oxidative stress mediated-apoptosis in Jurkat T lymphoblastic leukemia cells.

Inophyllin A (INO-A), a pyranoxanthone isolated from the roots of Calophyllum inophyllum represents a new xanthone with potential chemotherapeutic activity. In this study, the molecular mechanism of INO-A-induced cell death was investigated in Jurkat T lymphoblastic leukemia cells. Assessment of phosphatidylserine exposure confirmed apoptosis as the primary mode of cell death in INO-A-treated Jurkat cells. INO-A treatment for only 30 min resulted in a significant increase of tail moment which suggests that DNA damage is an early apoptotic signal. Further flow cytometric assessment of the superoxide anion level confirmed that INO-A induced DNA damage was mediated with a concomitant generation of reactive oxygen species (ROS). Investigation on the thiols revealed an early decrease of free thiols in 30 min after 50 µM INO-A treatment. Using tetramethylrhodamine ethyl ester, a potentiometric dye, the loss of mitochondrial membrane potential (MPP) was observed in INO-A-treated cells as early as 30 min. The INO-A-induced apoptosis progressed with the simultaneous activation of caspases-2 and -9 which then led to the processing of caspase-3. Taken together, these data demonstrate that INO-A induced early oxidative stress, DNA damage and loss of MMP which subsequently led to the activation of an intrinsic pathway of apoptosis in Jurkat cells.