Sulfated polysaccharide fucoidan isolated from brown algae shows a wide range of biological activities that are significantly dependent on its chemical composition, which is closely related to the applied technique and extraction parameters. Therefore, the objective of this study was to evaluate the influence of microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) parameters (solvent, temperature, time, and number of cycles) on the Fucus virsoides and Cystoseira barbata polysaccharide yield (%PS) and chemical composition (total sugar, fucose, and sulfate group). The optimal MAE parameters that resulted in the highest polysaccharide extraction from F. virsoides and C. barbata were 0.1 M H₂SO₄ for 10 min at 80 °C, while the optimal PLE parameters were 0.1 M H₂SO₄, for two cycles of 15 min at 140 °C. Furthermore, the %PS, chemical structure, molecular properties, and antioxidant activity of the F. virsoides and C. barbata polysaccharide extracts obtained with MAE, PLE, and conventional extraction (CE) performed under previously determinate optimal conditions were compared. PLE resulted in a significantly higher %PS from F. virsoides, while for C. barbata, a similar yield was achieved with CE and PLE, as well as CE and MAE, for both algae. Furthermore, the polysaccharides obtained using PLE had the highest polydispersity index, fucose, and sulfate group content, and the lowest uronic acid content; however their antioxidant activity was lower.

Macroalgae produce a wide range of monoterpenes as secondary metabolites of mevalonate (MVA) and/or methylerythritol phosphate (MEP) pathway (often including haloperoxidase action). Great biodiversity of macroalgal monoterpenes was reported including acyclic, monocyclic, and bicyclic structures. Halogenated monoterpenes exhibited significant biological activity (e.g., anticancer, antiplasmodial, and insecticidal) that is influenced by the number of present halogens (higher halogen content is preferable, especially bromine) and their position within the monoterpene skeleton. In distinction from the existing reviews, the present review provides novelty with respect to: (a) exclusively monoterpenes from red macroalgae are targeted; (b) biosynthesis, isolation, and analysis, as well as bioactivity of monoterpenes are represented; (c) the methods of their isolation, analysis, and structure elucidation are summarized; (d) the bioactivity of macroalgal monoterpenes is systematically presented with emphasis on anticancer activity; (e) the literature references were updated.

Bioactive compounds from plants play an important role in slowing many neurodegenerative diseases, such as Alzheimer’s disease, by inhibiting cholinesterase enzymes. Studies have shown that oxidative stress is associated with the development of Alzheimer’s disease. In traditional medicine of Bosnia and Herzegovina, Teucrium montanum is used to treat numerous diseases. The chemical composition and biological activity of the essential oil (EO) and aqueous (AE) and methanol extract (ME) of this plant were studied. The chemical composition of EO was studied using GC-MS, while the composition of the extracts was studied using HPLC-DAD. Antioxidant activity was tested using the DPPH and FRAP methods. The protection of lipids and proteins from oxidation was tested using the ammonium thiocyanate and BSA oxidation methods. The ability to inhibit cholinesterases was tested by the Ellman method. The main identified EO compounds were α-cadinol, ß-selinene, δ-cadinene, epi-α-cadinol, germacrene D-4-ol, and α-pinene. The main phenolic compounds of the extracts were p-coumaric acid, ellagic acid and caffeic acid. The tested extracts showed good antioxidant radical scavenging and reducing potential and a very good ability to protect lipids and proteins from oxidation. The EO showed moderate AChE and BChE inhibition potential, while the extracts showed weak or no ability.

A series of nine racemic trans-β-lactam ureas were analyzed for enantiomer separation by high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). The separations were performed on three immobilized polysaccharide-based chiral analytical columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB and CHIRAL ART Cellulose-SC). In HPLC mode, a normal-phase consisting of n-hexane/2-PrOH (90/10, v/v), a polar organic mobile phase consisting of 100% MeOH or 100% EtOH, and a non-standard mobile phase consisting of 100% dimethyl carbonate (DMC) were investigated. In SFC mode, the mobile phases CO₂/alcohol (80/20, v/v) and CO₂/DMC/alcohol (MeOH or EtOH; 70/24/6, v/v/v or 60/32/8, v/v/v) were investigated. The best achieved enantioseparation of trans-β-lactam ureas was obtained with an Amylose-SA column. We have shown that the green solvent dimethyl carbonate (DMC) can be efficiently used as a mobile phase in HPLC mode as well as in SFC mode along with the addition of polar organic modifiers (MeOH or EtOH).

The enantioseparation of syn- and anti-3,5-disubstituted hydantoins 5a–i was investigated on three immobilized polysaccharide-based columns (CHIRAL ART Amylose-SA, CHIRAL ART Cellulose-SB, CHIRAL ART Cellulose-SC) by high performance liquid chromatography (HPLC) using n-hexane/2-PrOH (90/10, v/v) or 100% dimethyl carbonate (DMC) as mobile phases, respectively, and by supercritical fluid chromatography (SFC) using CO₂/alcohol (MeOH, EtOH, 2-PrOH; 80/20, v/v) as a mobile phase. The chromatographic parameters, such as separation and resolution factors, have indicated that Amylose-SA is more suitable for enantioseparation of the most analyzed syn- and anti-3,5-disubstituted hydantoins than Celullose-SB and Cellulose-SC in both HPLC and SFC modalities. All three tested columns showed better enantiorecognition ability toward anti-hydantoins compared to syn-hydantoins, both in HPLC and SFC modes. We have demonstrated that environmentally friendly solvent DMC can be efficiently used as the mobile phase in HPLC mode for enantioseparation of hydantoins on the immobilized polysaccharide-based chiral stationary phases.