Percorrer por autor "Radman, Sanja"
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- Pretreatment tunes scCO2 extract composition and bioactivity in three microalgae: chemometric and molecular docking insightsPublication . Vladic, Jelena; Radman, Sanja; Besu, Irina; Stanojkovic, Tatjana; Zloh, Mire; Jerkovic, Igor; Banjac, Milica Karadzic; Ivkovic, Milena; Pereira, Hugo; Gouveia, LuisaThis study explores the impact of enzymatic (ENZ), microwave (MW), and ultrasound (US) pretreatments on supercritical CO2 (scCO2) extraction efficiency, chemical composition, and cytotoxic activity of Tetraselmis sp., Tetradesmus obliquus, and Chlorococcum sp. Pretreatments significantly enhanced extraction yields, with ENZ being most effective for Tetraselmis and Chlorococcum, and MW for T. obliquus. UPLC-HRMS profiling revealed species- and pretreatment-specific shifts: ENZ and US improved pigment recovery in Tetraselmis, while MW enriched carotenoids and chlorophyll derivatives. In Chlorococcum, MW boosted pigment diversity, whereas ENZ and US favored fatty acid derivatives in the extracts. Multivariate analysis confirmed significant compositional changes, particularly after ENZ and MW pretreatments. Tetraselmis extracts, especially those pretreated with MW, exhibited the strongest cytotoxic activity and highest selectivity indices against HeLa and MDA-MB-453 cancer cell lines. Correlation analysis identified compounds such as 2,3-dihydroxypropyl stearate, fucoxanthin, and (3β)-3-hydroxystigmast-5-en-7-one as strongly linked to cytotoxicity. Molecular docking further showed that abundant compounds in Tetraselmis extracts have high predicted affinities for cancer-related targets (e.g., BCL2, EGFR, PDK1). The results suggest that cytotoxic effects arise from both specific bioactive compounds and their synergistic interactions. These findings show that pretreatments can purposefully tune scCO2 extracts and provide a data-driven basis for designing more sustainable microalgal extraction workflows.
- Supercritical CO2 extract from Microalga Tetradesmus obliquus: the effect of high-pressure pre-treatmentPublication . Vladić, Jelena; Jerković, Igor; Radman, Sanja; Molnar Jazić, Jelena; Ferreira, Alice; Maletić, Snežana; Gouveia, LuisaHigh-pressure pre-treatment followed by supercritical carbon dioxide (ScCO2 ) extraction (300 bar, 40 ◦C) was applied for the attainment of the lipophilic fraction of microalga Tetradesmus obliquus. The chemical profile of supercritical extracts of T. obliquus was analyzed by ultra-highperformance liquid chromatography–high-resolution mass spectrometry with electrospray ionization (UHPLC-ESI-HRMS). Moreover, the impact of ScCO2 on the microbiological and metal profile of the biomass was monitored. The application of the pre-treatment increased the extraction yield approximately three-fold compared to the control. In the obtained extracts (control and pre-treated extracts), the identified components belonged to triacylglyceroles, fatty acid derivatives, diacylglycerophosphocholines and diacylglycerophosphoserines, pigments, terpenes, and steroids. Triacylglycerols (65%) were the most dominant group of compounds in the control extract. The pre-treatment decreased the percentage of triacylglycerols to 2%, while the abundance of fatty acid derivatives was significantly increased (82%). In addition, the pre-treatment led to an increase in the percentages of carotenoids, terpenoids, and steroids. Furthermore, it was determined that ScCO2 extraction reduced the number of microorganisms in the biomass. Considering its microbiological and metal profiles, the biomass after ScCO2 can potentially be used as a safe and important source of organic compounds.
