Effects of Extraction and Purification Methods on Degradation Kinetics and Stability of Lycopene from Watermelon under Storage Conditions

Isolation of Natural Products Using Preparative TLC

Known for their diverse and potent physiological activities, natural products continue to be essential for the discovery and development of new drugs. This chapter explores the pivotal role of preparative thin-layer chromatography (Prep-TLC) in the isolation of natural products. This chapter begins with an understanding of the historical significance and structural complexity of natural products, and discusses the problems caused by complex mixtures present in extracts, as well as the multifunctionality, cost-effectiveness, and compatibility with different sample types of Prep-TLC to address these challenges. We then explain the problems of separating these compounds and introduce Prep-TLC as a solution. The focus shifts to the fundamental principles and methodologies of Prep-TLC, highlighting its role in achieving the efficient separation and isolation of natural products. To illustrate the successful application of Prep-TLC to isolate bioactive compounds from various natural sources, real-world case and case studies are presented. In this chapter, we aim to provide practical assistance to researchers and practitioners by explaining the principles and methodologies of Prep-TLC that facilitate the discovery of novel physiologically active compounds.

Construction of a Calibration Curve for Lycopene on a Liquid-Handling Platform─Wider Lessons for the Development of Automated Dilution Protocols

Liquid-handling is a fundamental operation in synthetic biology─all protocols involve one or more liquid-handling operations. It is, therefore, crucial that this step be carefully automated in order to unlock the benefits of automation (e.g., higher throughput, higher replicability). In the paper, we present a study, conducted at the London Biofoundry at SynbiCITE, that approaches liquid-handling and its reliable automation from the standpoint of the construction of the calibration curve for lycopene in dimethyl sulfoxide (DMSO). The study has important practical industrial applications (e.g., lycopene is a carotenoid of industrial interest, DMSO is a popular extractant). The study was also an effective testbed for the automation of liquid-handling. It necessitated the development of flexible liquid-handling methods, which can be generalizable to other automated applications. In addition, because lycopene/DMSO is a difficult mix, it was capable of revealing issues with automated liquid-handling protocols and stress-testing them. An important component of the study is the constraint that, due to the omnipresence of liquid-handling steps, errors should be controlled to a high standard. It is important to avoid such errors propagating to other parts of the protocol. To achieve this, a practical framework based on regression was developed and utilized throughout the study to identify, assess, and monitor transfer errors. The paper concludes with recommendations regarding automation of liquid-handling, which are applicable to a large set of applications (not just to complex liquids such as lycopene in DMSO or calibration curves).

Degradation kinetics of lycopene from red amaranth & preparation of winter melon jelly using this lycopene and comparison with commercial jelly

This study was conducted to observe the storage conditions, such as solvent and temperature, of lycopene content and degradation kinetics from red amaranth (Amaranthus gangeticus). Jelly was prepared using the extracted lycopene, the physicochemical properties and lycopene content. The extract with the maximum amount of lycopene was obtained by extraction with hexane, acetone and ethanol (2:1:1),50 ± 9 mg/kg. Higher lycopene degradation was observed at refrigerated temperature as compared to ambient temperature in hexane acetone (6:4) solvent throughout the storage periods. In this period, the initial lycopene concentration was measured to be 17 ± 8 mg/kg, whereas at the end of the storage time, it was found to be 3.0 ± 0.8 mg/kg. Hence, the results indicate that the hexane, acetone, and ethanol (in a ratio of 2:1:1) solvent method is viable for extracting and purifying lycopene from red amaranth at refrigerated temperature. This lycopene can serve as both a natural colorant and a value-added product. However, it is worth noting that lycopene can also be extracted and purified using recrystallization, column chromatography, and thin-layer chromatography (TLC) methods. The Winter melon jelly using lycopene from red amaranth contained moisture 29.6 %, ash 0.67 %, acidity 0.35 %, reducing sugar 26.8 %, non-reducing sugar 35.4 %, total soluble solid 66°brix and lycopene content 26.04 mg/kg. Proper utilization of lycopene extracted from red amaranth during the preparation of bakery, confectionary, baby food etc., may help and encourage the development of small-scale industries in the country.

Natural Sources of Food Colorants as Potential Substitutes for Artificial Additives

In recent years, the demand of healthier food products and products made with natural ingredients has increased overwhelmingly, led by the awareness of human beings of the influence of food on their health, as well as by the evidence of side effects generated by different ingredients such as some additives. This is the case for several artificial colorants, especially azo colorants, which have been related to the development of allergic reactions, attention deficit and hyperactivity disorder. All the above has focused the attention of researchers on obtaining colorants from natural sources that do not present a risk for consumption and, on the contrary, show biological activity. The most representative compounds that present colorant capacity found in nature are anthocyanins, anthraquinones, betalains, carotenoids and chlorophylls. Therefore, the present review summarizes research published in the last 15 years (2008-2023) in different databases (PubMed, Scopus, Web of Science and ScienceDirect) encompassing various natural sources of these colorant compounds, referring to their obtention, identification, some of the efforts made for improvements in their stability and their incorporation in different food matrices. In this way, this review evidences the promising path of development of natural colorants for the replacement of their artificial counterparts.

Separation and Purification of Taxanes from Crude Taxus cuspidata Extract by Antisolvent Recrystallization Method

Taxanes are natural compounds with strong antitumor activity. In this study, we first enriched taxanes by ultrasonic extraction and liquid–liquid extraction from Taxus cuspidata, then purified these taxanes by the antisolvent recrystallization method, and discussed the effects of four recrystallization conditions on the purity of eight target compounds. The most promising purification results were obtained using methanol as a solvent and water as an antisolvent. Response surface methodology (RSM) was used to further optimize the optimal purification conditions: when the crude extraction concentration was 555.28 mg/mL, an antisolvent to solvent volume ratio was 28.16 times, the deposition temperature was 22.91 °C, and the deposition time was 1.76 min, the purity of the taxanes reached its maximum. The scanning electron microscopy (SEM) results showed that recrystallization could effectively reduce the particle size of crude Taxus cuspidata and control the particle morphology. X-ray diffraction (XRD) and Raman spectrum experiments demonstrated that the amorphous state of the crude Taxus cuspidata did not change during the recrystallization process, and always remained amorphous. This recrystallization method can effectively improve the purity of taxanes in Taxus cuspidata, and is suitable for the preliminary purification of taxanes.

Selected Methods of Extracting Carotenoids, Characterization, and Health Concerns: A Review

Carotenoids are the most powerful nutrients (medicine) on earth due to their potent antioxidant properties. The ability of these tetraterpenoids in obviating human chronic ailments like cancer, cardiovascular disease, osteoporosis, and diabetes has drawn public attention toward these novel compounds. Conventionally, carotenoids have been extracted from plant materials and agro-industrial byproduct using different solvents, but these procedures result in contaminating the target compound (carotenoids) with extraction solvents. Furthermore, some utilized solvents are not safe and hence are harmful to the environment. This has attracted criticism from consumers, ecologists, environmentalists, and public health workers. However, there is clear consumer preference for carotenoids from natural origin without traces of extracting solvent. Therefore, this review seeks to discuss methods for higher recovery of pure carotenoids without contamination from a solvent. Methods such as enzyme-based extraction, supercritical fluid extraction, microwave-assisted extraction, Soxhlet extraction, ultrasonic extraction, and postextraction treatment (saponification) are discussed. Merits and demerits of these methods along with health concerns during intake of carotenoids were also considered.