Phycobiliproteins (PBPs) are fluorescent proteins of various colors, including fuchsia, purple-blue and cyan, that allow the capture of light energy in auxiliary photosynthetic complexes called phycobilisomes (PBS). PBPs have several highly preserved structural and physicochemical characteristics. In the PBS context, PBPs function is capture luminous energy in the 450–650 nm range and delivers it to photosystems allowing photosynthesis take place. Besides the energy harvesting function, PBPs also have shown to have multiple biological activities, including antioxidant, antibacterial and antitumours, making them an interesting focus for different biotechnological applications in areas like biomedicine, bioenergy and scientific research. Nowadays, the main sources of PBPs are cyanobacteria and micro and macro algae from the phylum Rhodophyta. Due to the diverse biological activities of PBPs, they have attracted the attention of different industries, such as food, biomedical and cosmetics. This is why a large number of patents related to the production, extraction, purification of PBPs and their application as cosmetics, biopharmaceuticals or diagnostic applications have been generated, looking less ecological impact in the natural prairies of macroalgae and less culture time or higher productivity in cyanobacteria to satisfy the markets and applications that require high amounts of these molecules. In this review, we summarize the main structural characteristics of PBPs, their biosynthesys and biotechnological applications. We also address current trends and future perspectives of the PBPs market.

Plant alkaloids are natural secondary metabolites that have attracted great interest in the development of drugs for therapeutic applications due to their diverse bioactivities. For the pharmaceutical, cosmetic, and food industries, the development of alkaloid-based formulations is a long path that requires several steps (extraction, separation, isolation, and encapsulation) and diverse techniques of analysis (quantitative and qualitative). These conventional methodologies are not sustainable for the environment, especially at the pilot scale. In this context, the development and application of sustainable green chemistry throughout the entire process can be successfully achieved with supercritical fluid (SF) technology. In this review, we provide a comprehensive and critical overview of the recent applications of SF processes in the study of alkaloids and their future perspectives. A special focus on the development and applications of the on-line coupling of SF-extraction (SFE) with SF-chromatography (SFC) is given. This coupling permits the use of a completely environmentally friendly process of extraction and separation/isolation in semi-preparative and preparative modes. The stabilization of alkaloids through encapsulation and micronization permits the application of SF processes throughout the whole workflow, from plant matrix extraction to stable product development. In addition, the global alkaloid market and SFE economic feasibility at an industrial scale are discussed. Overall, SF technology is a versatile and eco-friendly alternative for the analysis and production of alkaloids that requires technical and analytical development according to the matrix and the chemical characteristics of the alkaloid.

A novel thin-layer chromatography (TLC)-based bioassay coupled with digital image analysis (DIA) was developed for rapid and non-targeted screening of angiotensin-converting enzyme (ACE) inhibitors in complex natural matrices. Conventional ACE inhibitory assays lack spatial resolution and rely on indirect measurements, limiting their applicability for effect-directed analysis (EDA). In this study, an on-surface enzymatic assay was implemented using hippuryl-histidyl-leucine (HHL) as substrate, followed by in situ derivatization of the generated hippuric acid with p-dimethylaminobenzaldehyde (DMAB) in an acetone:acetic anhydride system, producing an orange chromophore directly on the TLC plate. To overcome the inherent subjectivity of visual evaluation, a MATLAB-based DIA workflow was introduced to quantify the colorimetric response as pseudo-absorbance, enabling objective optimization of assay parameters. The blue channel provided the highest analytical sensitivity (R2 = 0.9984), and no significant matrix effects were observed (p = 0.09), confirming the robustness of the approach. Optimal conditions were established at 180 mU mL-1 ACE, 3 mM HHL, 30 min incubation, and 10% (w/v) DMAB. The method was applied to Peumus boldus alkaloidal extracts, enabling clear detection and localization of inhibitory zones poorly resolved by visual inspection. Subsequent isolation by micro-preparative TLC followed by UHPLC–DAD–MS/MS analysis enabled tentative identification of three aporphine alkaloids: norboldine (m/z 314.20 [M+H]+), boldine (m/z 328.10 [M+H]+), and laurotetanine (m/z 328.10 ([M+H]+). This integrated TLC–ACE–DIA platform, complemented by GNPS-assisted MS/MS annotation, provides a rapid, cost-effective, high-throughput strategy for discovery and prioritization of ACE inhibitors in natural products, significantly enhancing analytical capabilities of effect-directed analysis workflows.