Aurantoside J: a new tetramic acid glycoside from Theonella swinhoei. Insights into the antifungal potential of aurantosides.

The chemical investigation of an Indonesian specimen of Theonella swinhoei afforded four aurantosides, one of which, aurantoside J (5), is a new compound. The structure of this metabolite, exhibiting the unprecedented N-α-glycosidic linkage between the pentose and the tetramate units, has been determined through detailed spectroscopic analysis. The four obtained aurantosides have been tested against five fungal strains (four Candida and one Fusarium) responsible of invasive infections in immuno-compromised patients. The non-cytotoxic aurantoside I (4) was the single compound to show an excellent potency against all the tested strains, thus providing valuable insights about the antifungal potential of this class of compounds and the structure-activity relationships.

Dehydroconicasterol and aurantoic acid, a chlorinated polyene derivative, from the Indonesian sponge Theonella swinhoei.

The chlorinated polyene aurantoic acid (1) and the 4-methylene sterol dehydroconicasterol (2) were isolated from the Indonesian sponge Theonella swinhoei, and their structures were elucidated by interpretation of spectroscopic data. Aurantoic acid is a unique member in the class of naturally occurring conjugated polyene derivatives, while dehydroconicasterol is the likely biogenetic precursor of the major Theonella 4-methylene sterols.

Properties and Bioactivity of Carrageenan, Myofibril, and Collagen-Based Smoked Edible Films / Propiedades y bioactividad de películas comestibles ahumadas a base de carragenano, miofibrillas y colágeno

The objective of this study is to develop and evaluate the properties of smoked edible film (EF) composed of carrageenan, myofibril, and collagen. The smoked EF was prepared by incorporating 0.8% liquid smoke. The analysis focused on various parameters including pH, physical properties such as thickness, solubility, tensile strength, elongation percentage, and water vapor transmission rate (WVTR). Sensory evaluation was also conducted to assess the texture attributes of the coated product, including wateriness, firmness, elasticity, hardness, and juiciness. The findings revealed that the concentration of the ingredients influenced the thickness of the EF, with myofibril proteins exhibiting higher concentrations compared to carrageenan and collagen. Both collagen and myofibril demonstrated maximum solubility at a concentration of 6%, while carrageenan achieved optimal solubility at concentrations ranging from 2 to 2.5%. Carrageenan exhibited significantly higher tensile strength compared to myofibril and collagen, whereas collagen demonstrated greater elasticity than carrageenan and myofibril protein. Moreover, myofibril protein film exhibited a lower water vapor transmission rate compared to carrageenan and collagen films. In terms of sensory assessment, carrageenan displayed high elasticity and juiciness, while collagen and myofibril showed high firmness and hardness. All EFs showed better antioxidant activity compared to Trolox (EC50 < 95.57 µg/mL).(AU)