Lycopene Molecule Research Articles

Evaluation of novel carriers for enhanced dissolution of lycopene

Despite the antioxidant properties of lycopene, its poor water solubility reduces its efficiency and bioavailability. The study aimed to enhance the solubility of lycopene to improve its efficiency. To make lycopene more soluble, different carriers were added using physical mixing and solid-dispersion techniques. Then, the mechanisms of this solubility improvement were studied using solid-state characterization and docking studies. Out of 56 polymers and their combinations, isolated protein-whey (IWP) and polyvinylpyrrolidone-K30 (PVP-K30) showed the highest solubility for lycopene. These particles exhibited a more negative surface charge and a lower polydispersity index. Dissolution kinetics revealed that using IPW resulted in the highest release rate of lycopene. It was found that lycopene and β-lactoglobulin, an IPW component, have a hydrophobic bond. This makes a hydrophilic coating around the lycopene molecule. DSC results showed that lycopene could be in an amorphous state in IPW-lycopene formulations. The results of this study show how some food ingredients can improve the bioavailability of drugs that don’t dissolve well in water. This will help with future efforts to deliver drugs.

Lycopene destabilizes preformed Aβ fibrils: Mechanistic insights from all-atom molecular dynamics simulation

The therapeutic strategy employing destabilization of the preformed Aβ fibril by various natural compounds, as studied by experimental and computational methods, has been reported significant in curing Alzheimer’s disease (AD). However, lycopene (a carotenoid), from terpenes family, needs investigation for its destabilization potential of Aβ fibril. The highest antioxidant potential and ability to cross blood brain barrier makes lycopene a preferred choice as drug lead for treating AD. The current study focuses on investigating the destabilization potential and underpinning mechanism of lycopene on different polymorphic forms of Aβ fibril via Molecular Dynamics (MD) simulation. The key findings highlight binding of lycopene to the outer surface of the chain F of the fibril (2NAO). Herein G9, K16 and V18 residues were found to be involved in van der Waals with the methyl groups of the lycopene. Additionally, Y10 and F20 residues were observed to interact via π-π interactions with CC bonds of the lycopene. The surface mediated binding of lycopene to the fibril is attributed to the large size and structural rigidity of lycopene along with the bulky size of 2NAO and narrow space of fibrillar cavity. The destabilization of the fibril is evident by breakage of inherent H-bonds and hydrophobic interactions in the presence of one lycopene molecule. The lesser β-sheet content explains disorganization of the fibril and bars the higher order aggregation curbing neurotoxicity of the fibril. The higher concentration of the lycopene is not found to be linearly correlated with the extent of destabilization of the fibril. Lycopene is also observed to destabilize the other polymorphic form of Aβ fibril (2BEG), by accessing the fibrillar cavity and lowering the β-sheet content. The destabilization observed by lycopene on two major polymorphs of Aβ fibril explains its potency towards developing an effective therapeutic approach in treating AD.

LYC loaded ferritin nanoparticles for intracerebral delivery and the attenuation of neurodegeneration in D-gal-induced mice

Recombinant human H-ferritin nanocage (rHuHF) loaded with natural antioxidative lycopene molecules (LYC) was successfully constructed for the first time, aiming to enrich LYC in the brain and explore the regulation mechanism of this nanoparticles on neurodegeneration. Here, the mouse model was constructed via D-galactose-induced neurodegeneration based on behavioural analysis, histological observation, immunostaining analysis, Fourier transform infrared microscopy, and Western blotting analysis for the regulation of rHuHF-LYC. rHuHF-LYC improved the behaviour of mice in a dose-dependent manner. Besides, rHuHF-LYC can attenuate neuronal damage, maintain the number of Nissl body, increase the level of unsaturated fat, inhibit the activation of glial cells, and prevent excessive accumulation of neurotoxic proteins in the hippocampus of mice. More importantly, synaptic plasticity was activated in response to the regulation of rHuHF-LYC with excellent biocompatibility and biosafety. This study proved the validity of the direct use of natural antioxidant nano drugs for treating neurodegeneration, providing a promising therapeutic option against further imbalances in the degenerative brain microenvironment.

Additional effects of Extra Virgin Olive Oil (EVOO) on the Physicochemical Stability of Tomato Paste as aTopical Anti-Aging

Lycopene is one of potential antioxidants which has anti-aging effect. Tomato products, especially tomato paste contains a lot of lycopenes. During storage, the autooxidation of lycopene causes the instability of lycopene itself. Lycopene can be degradated and it will lead to fragmentation of the lycopene molecule. The addition of oil can prevent the autooxidation process in lycopene by blocking this action. The aim of this research is to determine the effect of Extra Virgin Olive Oil (EVOO) addition on physicochemical stability of tomato paste. In this research, tomato paste was made by steaming method and the preparation resulted in two types, tomato paste with EVOO addition and tomato paste without EVOO addition. The physicochemical stability was examined in real-time test and thermal cycling test methods. The evaluation of characteristics included organoleptic, spreadibility, pH, and tomato paste content as lycopene levels. The real-time measurements (25-28oC) showed that the addition of EVOO could maintain the tomato paste characteristic (organoleptic, spreadibility, pH, and tomato paste content). The reaction rate (k) showed that the stability of lycopene content in tomato paste either with or without EVOO addition followed the first order reaction. As a result, it was found that tomato paste without EVOO addition had lower stability compared to tomato paste with EVOO addition. Temperature changes in the thermal cycling test method did not affect the organoleptic, pH, and lycopene content stability of tomato paste.

Lycopene Scavenges Cellular ROS, Modulates Autophagy and Improves Survival through 7SK snRNA Interaction in Smooth Muscle Cells.

The chance of survival rate and autophagy of smooth muscle cells under calcium stress were drastically improved with a prolonged inclusion of Lycopene in the media. The results showed an improved viability from 41% to 69% and a reduction in overall autophagic bodies from 7% to 3%, which was well in agreement with the LC3II and III mRNA levels. However, the proliferation was slow compared to the controls. The fall in the major inflammatory marker TNF-α and improved antioxidant enzyme GPx were regarded as significant restoration markers of cell survival. The reactive oxygen species (ROS) were reduced from 8 fold to 3 fold post addition of lycopene for 24 h. Further, the docking studies revealed binding of lycopene molecules with 7SK snRNA at 7.6 kcal/mol docking energy with 300 ns stability under physiological conditions. Together, these results suggest that Lycopene administration during ischemic heart disease might improve the functions of the smooth muscle cells and 7SK snRNA might be involved in the binding of lycopene and its antioxidant protective effects.

Relations between the Raman spectra and molecular structure of selected carotenoids: DFT study of α-carotene, β-carotene, γ-carotene and lycopene

Using the density functional theory (DFT), we calculated the structures and Raman spectra of trans-isomers of α-carotene, β-carotene, γ-carotene and lycopene as well as trans-isomers of modified β-carotene and lycopene molecules with substituted end or/and side groups. The DFT calculations showed that the position of the CC stretching band depends mainly on the number of conjugated CC bonds and decreases with an increase in the conjugation length. The weak dependence of the position of the CC stretching band on the structure of the carotenoid side and end groups suggests that this band can be used to evaluate the conjugation length for trans-isomers of various molecules containing polyene chains. The CC stretching band shifts towards lower wavenumbers with growth of the conjugation length or masses of the end groups and to higher wavenumbers in the presence of the side CH3 groups. The intensities of the CC and CC stretching bands are enhanced with growth of the conjugation length or masses of the end groups. The presence of the side CH3 groups results in bending of the carotenoid backbone, splitting and dumping of intensities of the CC and CC stretching bands.

Lycopene protects sperm from oxidative stress in the experimental varicocele model.

Oxidative stress (OS) is an important parameter in the evaluation of infertility caused by varicocele. Antioxidants are the most commonly prescribed drugs in these patients. Lycopene molecule, as the powerful antioxidant in the carotenoid family, has beneficial effects on improving fertility in males. Therefore, we investigated the effects of lycopene on induced OS by varicocele in an animal model. Forty‐five adult male Wistar rats were divided into two groups: control (n = 12) and varicocele (n = 33). Two months after induced varicocele, five rats in each group were sacrificed randomly and induced varicocele was investigated. Remained rats were divided into five groups (n = 7), including the control (I), varicocele (II), varicocele reserving solvent (III), varicocele reserving lycopene 4 mg/kg (IV), and 10 mg/kg (V) for two months. At the end of the experiment, intracellular reactive oxygen species (ROS), malondialdehyde (MDA), total antioxidant capacity (TAC), %DNA damage, and antioxidant enzymatic levels were measured. The results indicated that there were significant increases in the levels of ROS, MDA, DNA damage, superoxide dismutase (SOD), sperm concentration, and motility in the varicocele groups compared with the control group. In the lycopene group (10 mg/kg), sperm concentration, the levels of TAC, and catalase (CAT) activity were improved so the levels of ROS, MDA, and %DNA damage were reduced compared with varicocele group. Our findings indicated that the administration of lycopene especially at a dose of 10 mg/kg in the varicocele group could protect sperm from OS and sperm DNA damage by increasing antioxidant activity and reducing ROS.

Current Status of Optical Systems for Measuring Lycopene Content in Fruits: Review

Optical systems are used for analysing the internal composition and the external properties in food. The measurement of the lycopene content in fruits and vegetables is important because of its benefits to human health. Lycopene prevents cardiovascular diseases, cataracts, cancer, osteoporosis, male infertility, and peritonitis. Among the optical systems focused on the estimation and identification of lycopene molecule are high-performance liquid chromatography (HPLC), the colorimeter, infrared near NIR spectroscopy, UV-VIS spectroscopy, Raman spectroscopy, and the systems of multispectral imaging (MSI) and hyperspectral imaging (HSI). The main objective of this paper is to present a review of the current state of optical systems used to measure lycopene in fruits. It also reports important factors to be considered in order to improve the design and implementation of those optical systems. Finally, it was observed that measurements with HPLC and spectrophotometry present the best results but use toxic solvents and require specialized personnel for their use. Moreover, another widely used technique is colorimetry, which correlates the lycopene content using color descriptors, typically those of CIELAB. Likewise, it was identified that spectroscopic techniques and multispectral images are gaining importance because they are fast and non-invasive.

Development of a Highly Water-Soluble Lycopene Cyclodextrin Ternary Formulation by the Integrated Experimental and Modeling Techniques.

Lycopene, the aliphatic hydrocarbon carotenoid with abundant bioactivities, has instability, extremely poor water solubility, and low oral bioavailability. The study aimed to develop a highly water-soluble and practical lycopene formulation to improve the oral bioavailability and efficiency of lycopene. Environment-friendly hot-melt extrusion (HME) technique was applied to fabricate lycopene-cyclodextrin-polyethylene glycol 6000 (PEG 6000) ternary systems, which possessed highly aqueous solubility (897.665μgmL-1), almost 32-fold higher than that of the reported lycopene binary inclusion (27.1 ± 3.2μgmL-1). The dissolution rate was significantly accelerated compared to pure lycopene. The molecular mechanism was further investigated by the integrated experimental and modeling tools. Molecular dynamics (MD) simulation revealed lycopene molecule was wrapped within the aggregates of hydroxypropyl-beta-cyclodextrin (HP-β-CD) and PEG 6000 through extensive hydrogen bond interactions, which was experimentally validated by DSC, XRD, and FTIR spectrum analysis. The third component PEG 6000 facilitated the process of HME and augmented hydrogen bond interactions with HP-β-CD. Moreover, lycopene inclusions exhibited significant antitumor activity via inhibiting cell proliferation and inducing apoptosis. The pharmacokinetic studies showed the relative bioavailability of lycopene ternary preparation was up to 313.08% and the Cmax was 4.9-fold higher than that of the marketed tablet. In conclusion, the lycopene cyclodextrin ternary formulation developed by the modified HME techniques is suitable for industrial production, while PEG 6000 plays a vital part in the multicomponent systems to increase solubility, dissolution rate, and oral bioavailability of lycopene. The combination of experimental and computational tools is able to benefit the development of multicomponent formulations accurately and effectively.

Using biopolymer bodies for encapsulation of hydrophobic products in bacterium

Producing some small hydrophobic molecules in microbes is challenging. Often these molecules cannot cross membranes, and thus their production may be limited by lack of storage space in the producing organism. This study reports a new technology for in vivo storage of valuable hydrophobic products in/on biopolymer bodies in Escherichia coli. A biodegradable and biocompatible polyester – poly (3-hydroxybutyrate) (PHB) – was selected as the intracellular storage vessel to encapsulate lycopene, which is a chromogenic model compound. The hydrophobic interaction between lycopene and PHB was verified by using in vitro binding test and sucrose density gradient centrifugation. Further in vivo characterization was performed by using Confocal Laser Scanning Microscopy (CLSM). The images validated the in vivo co-localization between PHB granules and lycopene. The images also showed that lycopene aggregated in bacteria that did not produce PHB, which may challenge the commonly accepted hypothesis that most lycopene molecules are stored in cell membranes of recombinant host. We also confirmed that producing PHB did not negatively affect lycopene biosynthesis in the E. coli strains and collected data suggesting that PHB titer and lycopene titer were positively correlated when the cells were engineered to co-produce them. The biopolymers that encapsulated hydrophobic molecules could have many useful applications, especially in controlled release because the polymers are biodegradable, and the encapsulated products would be released during the polymer degradation.

Application of Stable Isotope Tracing to Elucidate Metabolic Dynamics During Yarrowia lipolytica α-Ionone Fermentation.

SummaryTargeted metabolite analysis in combination with 13C-tracing is a convenient strategy to determine pathway activity in biological systems; however, metabolite analysis is limited by challenges in separating and detecting pathway intermediates with current chromatographic methods. Here, a hydrophilic interaction chromatography tandem mass spectrometry approach was developed for improved metabolite separation, isotopologue analysis, and quantification. The physiological responses of a Yarrowia lipolytica strain engineered to produce ∼400 mg/L α-ionone and temporal changes in metabolism were quantified (e.g., mevalonate secretion, then uptake) indicating bottleneck shifts in the engineered pathway over the course of fermentation. Dynamic labeling results indicated limited tricarboxylic acid cycle label incorporation and, combined with a measurable ATP shortage during the high ionone production phase, suggested that electron transport and oxidative phosphorylation may limit energy supply and strain performance. The results provide insights into terpenoid pathway metabolic dynamics of non-model yeasts and offer guidelines for sensor development and modular engineering.

Investigations on thermostability of carotenoids from tomato peels in oils using a kinetic approach

Our study focused on the characterization of the extract obtained from tomato peels. The chromatographic profile revealed the presence of lycopene and β-carotene. The in silico tests suggested that the thermal treatment of lycopene molecules pairs at temperatures over 100°C cause the alteration of all-trans conformation into 9,9′cis lycopene, which might decrease its biological activity. Also, the thermal degradation of the total carotenoids, β-carotene, and lycopene was studied in the temperature range 100–145°C and followed a first-order kinetic model, with activation energy of 81.76 ± 6.82 kJ/M, 89.81 ± 8.48 kJ/M, and 79.66 ± 4.03 kJ/M, respectively. The Rancimat analysis indicated that the enriched peanut and cotton oils with extract displayed higher induction time values, thus showing a protection factor of the tomato-derived carotenoids. The present results highlighted the thermostability of carotenoids in vegetable oils and the potential of using tomato peel as a valuable source of biologically active compounds, with antioxidative properties. Practical applications Our study explores the possibilities of reuse the underutilized tomato-derived by-products, rich in biologically active compounds such as lycopene and β-carotene. The results are valuable because the thermal degradation mechanisms of the main biologically active compounds extracted from tomato peels are described by two methods: classical kinetic models and in silico approach. Both methods have highlighted the degradation of lycopene and β-carotene, with an impact on antioxidant activity. The present study provides cumulative information for the selection of industrial processing parameters from the perspective of preservation of bioactives and obtaining the desired quality end products. The extracts have gained also applicative value in our study, being tested for its protective effect on commercial vegetable oils, but also for improving their antioxidant activity and color.

Physical properties of oil-in-water nanoemulsions stabilized by OSA-modified starch for the encapsulation of lycopene

The principles of formation and stability of nutrient-loaded nanoemulsions have been extensively investigated in previous research. In this study, we focus on the impact of lycopene on the formation and physical properties of oil-in-water nanoemulsions stabilized by octenyl succinate anhydride (OSA) modified starch. Lycopene nanoemulsions were fabricated using high-pressure homogenization and using medium chain triglycerides (MCT) as carrier oils. The DSC and FTIR-ATR results showed lycopene was amorphous and was encapsulated in the nanoemulsion droplet successfully. When the lycopene concentration ranged from 0.1 wt. % to 0.5 wt. %, the particle size decreased significantly. Raman and NMR measurements suggested that lycopene molecules lie in the hydrophobic core of the O/W nanoemulsion droplets when the concentration of lycopene is low. As the lycopene loading increased, its molecules stretched into the O/W interface, strengthening the lateral packing of OSA molecules on the interfacial membranes, and then decreasing the mean particle diameters and improved the stability of nanoemulsions, which is consistent with the results of Turbiscan AGS stability analyses. In summary, the incorporation of lycopene and the interaction between the lycopene and OSA molecules play an important role on the physical properties of the nanoemulsions.

Unveiling the Aggregation of Lycopene in Vitro and in Vivo: UV-Vis, Resonance Raman, and Raman Imaging Studies.

The present study investigates the structure of lycopene aggregates both in vitro and in vivo using ultraviolet-visible (UV-vis) and Raman spectroscopies. The electronic absorption bands of the J- and H-aggregates in vitro shift to lower and higher energies, respectively, compared to that of the lycopene monomer. Along with these results, the frequencies of the ν1 Raman bands were shifted to lower and higher frequencies, respectively. By plotting the frequencies of the ν1 Raman band against the S0 → S2 transition energy, a linear relationship between the data set with different aggregation conformations can be obtained. Therefore, the band positions depending on the different conformations can be explained based on the idea that the effective conjugated C═C chain lengths within lycopene molecules are different due to the environmental effect (site-shift effect) caused by the aggregation conformation. Applying this knowledge to the in vivo measurement of a tomato fruit sample, the relationship between the aggregation conformation of lycopene and the spectral patterns observed in the UV-vis as well as Raman spectra in different parts of tomato fruits was discussed in detail. The results showed that the concentration of lycopene (particularly that of the J-aggregate) specifically increased, whereas that of chlorophyll decreased, with ripening. Furthermore, Raman imaging indicated that lycopene with different aggregate conformations was distributed inhomogeneously, even within one sample. The layer formation in tomato tissues with high concentrations of J- and H-aggregates was successfully visualized. In this manner, the presence of lycopene distributions with different aggregate conformations was unveiled in vivo.

Synthesis of apo-13- and apo-15-lycopenoids, cleavage products of lycopene that are retinoic acid antagonists

Consumption of the tomato carotenoid, lycopene, has been associated with favorable health benefits. Some of lycopene's biological activity may be due to metabolites resulting from cleavage of the lycopene molecule. Because of their structural similarity to the retinoic acid receptor (RAR) antagonist, β-apo-13-carotenone, the “first half” putative oxidative cleavage products of the symmetrical lycopene have been synthesized. All transformations proceed in moderate to good yield and some with high stereochemical integrity allowing ready access to these otherwise difficult to obtain terpenoids. In particular, the methods described allow ready access to the trans isomers of citral (geranial) and pseudoionone, important flavor and fragrance compounds that are not readily available isomerically pure and are building blocks for many of the longer apolycopenoids. In addition, all of the apo-11, apo-13, and apo-15 lycopenals/lycopenones/lycopenoic acids have been prepared. These compounds have been evaluated for their effect on RAR-induced genes in cultured hepatoma cells and, much like β-apo-13-carotenone, the comparable apo-13-lycopenone and the apo-15-lycopenal behave as RAR antagonists. Furthermore, molecular modeling studies demonstrate that the apo-13-lycopenone efficiently docked into the ligand binding site of RARα. Finally, isothermal titration calorimetry studies reveal that apo-13-lycopenone acts as an antagonist of RAR by inhibiting coactivator recruitment to the receptor.

Enhanced E/Z Isomerization of (All-E)-lycopene by Employing Iron(III) Chloride as a Catalyst.

Catalytic isomerization of (all-E)-lycopene to Z-isomers using iron(III) chloride was investigated and optimized under various conditions of solvents, concentrations of iron(III) chloride, and reaction temperatures. The total contents of Z-isomers converted were higher in the order of CH2 Cl2 (78.4%) > benzene (61.4%) > acetone (51.5%) > ethyl acetate (50.8%) at 20 °C for 3 h using 1.0 × 10(-3) mg/mL iron(III) chloride for 0.1 mg/mL (all-E)-lycopene. However, the decomposition of lycopene was markedly accelerated in CH2 Cl2 : the remaining lycopene after the reaction for 3 h and 12 h was only 79.4% and 47.5%, respectively. As the concentration of catalyst increased in acetone, the Z-isomerization ratio of lycopene increased to more than 80%, followed by rapid degradation of lycopene to undetectable levels using >4.0 × 10(-3) mg/mL iron(III) chloride with the above concentration of (all-E)-lycopene. Finally, greater isomerization (79.9%) was attained at 60 °C in acetone for 3 h in the presence of 1.0 × 10(-3) mg/mL iron(III) chloride, largely without decomposition of lycopene (remaining ratio of total amount of lycopene isomers after the reaction, 96.5%). As iron(III) chloride has found general use as a food additive for iron fortification and acetone is also widely used in the food field, this method can be applied to the food and beverage processing industry. The dietary intake of lycopene, a natural red pigment found in brightly colored vegetables and fruits such as tomatoes and watermelons, has been reported to lower the risk of some diseases, including cancer. Lycopene molecules occur naturally in a long and “straight” shape, but on the other hand lycopene molecules with “bent” forms are highly absorbed by living cells, and showed good antioxidant activity. This study has demonstrated the efficient production of the “bent” lycopene using ionic iron as an accelerator, which is often contained in nutritional supplements.

Overexpression and Characterization of Lycopene Cyclase (CrtY) from Marine Bacterium Paracoccus haeundaensis

Lycopene cyclase converts lycopene to beta-carotene by catalyzing the formation of two beta-rings at each end of the linear carotene structure. This reaction takes place as a two-step reaction in which both sides of of the lycopene molecule are cyclized into beta-carotene rings via the monocyclic gamma-carotene as an intermediate. The crtY gene coding for lycopene cyclase from Paracoccus haeundaensis consists of 1,158 base pairs encoding 386 amino acids residues. An expression plasmid containing the crtY gene (pET44a-CrtY) was constructed and expressed in Escherichia coli, and produced a recombinant protein of approximately 43 kDa, corresponding to the molecular mass of lycopene cyclase. The expressed protein was purified to homogeneity by His-tag affinity chromatography and showed enzymatic activity corresponding to lycopene cyclase. We also determined the lycopene substrate specificity and NADPH cofactor requirements of the purified protein. The Km values for lycopene and NADPH were 3.5 microM and 2 mM, respectively. The results obtained from this study will provide a wider base of knowledge on the enzyme characterization of lycopene cyclase at the molecular level.

Lycopene recovery from tomato peel under mild conditions assisted by enzymatic pre-treatment and non-ionic surfactants.

The tomato processing industry generates large quantities of tomato peel residues, usually creating environmental problems. These residues are a significant source of lycopene, thus providing an attractive alternative for profitable handling of these otherwise problematic by-products. The enzymatic pretreatment of these residues for lycopene recovery has already been employed, although the use of surfactants for enhancing the recovery has not been examined so far. The enzymatic pretreatment of tomato peels, using two commercially available pectinolytic enzyme preparations, was evaluated suggesting that there is an optimum pretreatment time of about 1 h, enzyme amount 250 Units/mL and no significant pH influence. Lycopene surfactant - assisted extraction was further investigated, showing that, among eight surfactants used, the most suitable was "Span 20", with an optimum ratio of 6-7 surfactant molecules per lycopene molecule. Sequential enzymatic pretreatment and surfactant-assisted extraction (30 min for each step) was evaluated leading to an improved lycopene extraction yield, with a somewhat smaller surfactant molar ratio (i.e. 4-5). In the latter case, the yield of lycopene recovery was almost four times greater compared to just 1 hr enzymatic pretreatment, and was approximately ten times greater compared to the recovery from untreated peels. Furthermore, such lipophilic compound recovery, avoiding the use of organic solvents, is environmentally attractive and ensures direct lycopene use in the food and cosmetics industries.

CDNA cloning of a novel gene codifying for the enzyme lycopene β-cyclase from Ficus carica and its expression in Escherichia coli

Lycopene beta-cyclase (β-LCY) is the key enzyme that modifies the linear lycopene molecule into cyclic β-carotene, an indispensable carotenoid of the photosynthetic apparatus and an important source of vitamin A in human and animal nutrition. Owing to its antioxidant activity, it is commercially used in the cosmetic and pharmaceutical industries, as well as an additive in foodstuffs. Therefore, β-carotene has a large share of the carotenoidic market. In this study, we used reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE)-PCR to obtain and clone a cDNA copy of the gene Lyc-β from Ficus carica (Lyc-β Fc), which codes for the enzyme lycopene β-cyclase (β-LCY). Expression of this gene in Escherichia coli produced a single polypeptide of 56 kDa of weight, containing 496 amino acids, that was able to cycle both ends of the lycopene chain. Amino acid analysis revealed that the protein contained several conserved plant cyclase motifs. β-LCY activity was revealed by heterologous complementation analysis, with lycopene being converted to β-carotene as a result of the enzyme's action. The β-LCY activity of the expressed protein was confirmed by high-performance liquid chromatography (HPLC) identification of the β-carotene. The lycopene to β-carotene conversion rate was 90%. The experiments carried out in this work showed that β-LYC is the enzyme responsible for converting lycopene, an acyclic carotene, to β-carotene, a bicyclic carotene in F. carica. Therefore, by cloning and expressing β-LCY in E. coli, we have obtained a new gene for β-carotene production or as part of the biosynthetic pathway of astaxanthin. So far, this is the first and only gene of the carotenoid pathway identified in F. carica.

Trans–cis isomerisation of the carotenoid lycopene upon complexation with cholesteric polyester carriers investigated by Raman spectroscopy and density functional theory

AbstractRaman spectroscopy and density functional theory (DFT) were used in this work for the structural characterisation of lycopene, the antioxidant carotenoid, and its complexes with two synthetic thermotropic cholesteric polyesters. Both polyesters were employed successfully to encapsulate the carotenoid lycopene (Lyc). Besides protecting it from oxidation, they induced the trans–cis isomerisation of lycopene towards the more biologically active and bioavailable isomer cis‐Lyc. The Raman spectra revealed changes mainly concerning the band ν1 and bands of methyl groups. This would explain the interaction mechanism between lycopene and cholesteric polyesters, inducing structural changes in the carotenoid by formation of a cis CC bond in central positions of the isomer chain and hydrophobic interaction that affects the side methyl groups. DFT calculations confirmed that the isomerisation occurs at central positions of lycopene molecule. The analysis of ν1 and ν2 bands and those of methyl groups in the calculated spectra of lycopene indicates that the interaction with the synthetic cholesteric polyesters could mainly lead to the 13‐cis‐Lyc isomer. The analysis of marker structural bands of the polyesters revealed structural changes in the host which mainly affect the ester groups, most probably due to a restructuring of the polyester chain to better accommodate the ligand. Copyright © 2010 John Wiley & Sons, Ltd.