Heterogeneous Compounds Research Articles

Synthesis caracterizcation of some Schiff bases derived from vanillin containing 1,3,4-thiadiazole moiety

The aim of this paper, thy schiff bases 1, 3, 4- Thaidiazol organic Compounds with high pharm. acological efficacy, wich play akay important vole in the tratment of urinary track infections, as anti-inflammatory, antimicrobial, anti-bacterial, analgesic, pain relief treatment of diabetics, attiveral, and anti-concer in this research, Vanillen has been used as abioimportant precursor. the Vanillen together, thiosimicarbizid is reated in the Presonce of ethanol to yield the substituted thiesimicarbazid compounds which are used in the preparation of several heterogeneous ving compounds include substituents (1,3,4-thiad; Zol-2-yl) thiesimcarbazide reacts with Sodium acetate in the presence of a lithium steak and the substituted thiosimi carbazide Compounds are also Irapped 4 (5-amino-1; 3; 4- thiadizol-2-yl) 2-methox phenol substituted by its reaction with phosphors Penta Sulfide- the vehicles prepared were diagnosed by the physical and spectral by IR methods of the nuclear magnetic resonance spectrum (H-NMR)

Using machine learning to quantify sources of light-absorbing water-soluble humic-like substances (HULISws) in Northeast China

Water-soluble humic-like substances (HULISws) are a group of heterogeneous organic compounds in the atmosphere, greatly impacting climate change and human health. As the most significant biomass burning (BB) and fossil fuel burning polluted area in China, Northeast China Plain could generate more light absorbing HULISws to the atmosphere. In this work, daily fine particle (PM2.5) samples were collected in Changchun, located in Northeast China Plain, from October 17th to November 29th, 2016, to investigate the potential sources of optical properties of HULISws. Here, the whole sampling period was divided into three sub-periods using the density of fire spots and the timeline of the central heating: the non-heating (October 17th to October 24th), early heating (October 25th to November 13th), and normal heating (November 14th to November 29th) periods. The mean mass concentrations of HULISws were 4.2 ± 1.2, 8.6 ± 3.6, and 2.4 ± 1.3 μg m−3 during the non-heating, early heating, and normal heating periods, respectively. The positive matrix factorization (PMF) model results suggested that the contribution of primary BB, secondary BB, and fossil fuel burning emissions were 46%, 24%, and 19% during the non-heating period, 22%, 29%, and 17% during the early heating period, and 13%, 16%, and 50% during the normal heating period, respectively. Combining the PMF results with the random forest (RF) algorithm, the contribution of each source to the optical properties was quantified. Here, BB still dominated the optical properties of HULISws in Northeast China. During the study period, the primary BB and secondary BB contributed 25% and 34% in the light absorption coefficient (Abs), 22% and 33% in the mass absorption exponent (MAE), and 17% and 33% in the absorption Ångström exponent (AAE), respectively. Other sources like cooking and fossil combustion contributed 25% and 35% in Abs, 35% and 26% in MAE, and 16% and 33% in AAE, respectively.

Artificial intelligence uncovers carcinogenic human metabolites.

The genome of a eukaryotic cell is often vulnerable to both intrinsic and extrinsic threats owing to its constant exposure to a myriad of heterogeneous compounds. Despite the availability of innate DNA damage responses, some genomic lesions trigger malignant transformation of cells. Accurate prediction of carcinogens is an ever-challenging task owing to the limited information about bona fide (non-)carcinogens. We developed Metabokiller, an ensemble classifier that accurately recognizes carcinogens by quantitatively assessing their electrophilicity, their potential to induce proliferation, oxidative stress, genomic instability, epigenome alterations, and anti-apoptotic response. Concomitant with the carcinogenicity prediction, Metabokiller is fully interpretable and outperforms existing best-practice methods for carcinogenicity prediction. Metabokiller unraveled potential carcinogenic human metabolites. To cross-validate Metabokiller predictions, we performed multiple functional assays using Saccharomyces cerevisiae and human cells with two Metabokiller-flagged human metabolites, namely 4-nitrocatechol and 3,4-dihydroxyphenylacetic acid, and observed high synergy between Metabokiller predictions and experimental validations.

612 Theabrownin in black tea suppresses UVB-induced MMP-1 expression in HaCaT keratinocytes

Theabrownin is a heterogeneous polyphenolic compound, obtained from fermented dark teas, with many bioactive functions. However, the role of theabrownin in skin photoaging remains unclear. In this study, we investigated whether theabrownin modulates ultraviolet B (UVB)-induced matrix metalloprotease-1 (MMP-1) expression in HaCaT keratinocytes. Theabrownin exerted antioxidant properties, which resulted in scavenging of intracellular reactive oxygen species generated by UVB irradiation in HaCaT cells.

Heterophase Synthesis of Humic Substances at Low Substrate Concentrations and Flow-Through Conditions

—Humic substances (HS) are heterogeneous and polydisperse compounds formed in soils, sediments and waters during the decay and transformation of organic residues (the process called humification). The role of extracellular free-radical condensation reactions (secondary synthesis) in the formation of HS is a subject of debate. Here we have studied the formation of HS from a mixture of monomers under the dynamic conditions and at low substrate concentrations in the presence of laccase from the fungus Coprinus comatus F-2940. Laccase was immobilized on kaolinite modified with aluminum hydroxide. We have investigated some properties of the enzyme, reactivity of phenolic acids and amino acids in the presence of laccase. The optimum of 2.6-dimethoxyphenol (2.6-DMP) oxidation by free laccase was at pH 6.0. Upon immobilization, it shifted to the acidic region (pH 4.4), the thermal stability decreased, however the kinetic parameters of 2.6-DMP oxidation remained unchanged. In terms of reactivity (% of substrate conversion by free laccase) the individual phenolic acids formed a series: caffeic (72) > ferulic (53) > gallic = syringic (43) > protocatechuic (5.5) > vanillic = p-hydroxybenzoic (0). In the mixture of phenolic acids, gallic acid was most efficiently oxidized (50%), while the other acids were oxidized in comparable amounts (13–17%). The conversion of phenolic acids increased in the presence of lysine. When a mixture of gallic, protocatechuic, syringic, ferulic acids (0.01 mM each) and lysine (0.02 mM) was passed through a flow-through microcolumn, immobilized laccase effectively oxidized the phenolic acids, the reaction products bound to the mineral phase, staining it dark. According to high performance liquid chromatography, the molecular weights of compounds extracted from the mineral phase did not exceed 900 Da, thus fulvic acid-like substances were formed. Results of the study suggest an important role of free-radical heterophase reactions in the formation of the molecular composition of the liquid phase and organo-mineral complexes.

Methods to investigate advanced glycation end-product and their application in clinical practice.

Advanced glycation end-products (AGEs) are heterogeneous compounds of irreversible adducts principally derived from nonenzymatic glycation and glycoxidation of proteins. An increase in AGEs may be involved in the pathogenesis of metabolic and cardiovascular diseases, chronic degenerative diseases, neurological diseases and cancer, and it has been suggested as a biomarker of oxidative stress. AGEs have been evaluated in different biological fluids, as well as in tissues. The most utilized techniques for AGE measurement can be divided into immunochemical methods, such as ELISA, and bioanalytical methods, including fluorescence spectroscopy, high-performance liquid chromatography, liquid chromatography-mass spectroscopy, gas chromatography-mass spectroscopy. However, the lack of reference values, well-established standard molecules, and standardized methods to measure these compounds, could limit the application of AGE evaluation for clinical purpose. Aim of this review is to provide an overview on the state of the art of the most employed techniques for detection and measurement of AGEs and their application in clinical practice.

Size-Induced Highly Selective Synthesis of Organometallic Rectangular Macrocycles and Heterometallic Cage Based on Half-Sandwich Rhodium Building Block.

The controlled synthesis of organometallic supramolecular macrocycles cages remains interesting and challenging work in the field of supramolecular chemistry. Here, two tetranuclear rectangular macrocycles and an octuclear cage were designed and synthesized utilizing a rigid and functionalized pillar linker, 2,6-bis(pyridin-4-yl)-1,7-dihydrobenzo [1,2-d:4,5-d′]diimidazole (BBI4PY) based on three half-sandwich rhodium building blocks bearing different sizes. X-ray crystallography in combination with 1H NMR spectroscopy elucidated that the two building blocks with shorter spacers only result in rectangular macrocycles. However, the building block of bulkier size to avoid the π-π stacking interactions between two ligands BBI4PY led to the formation of an octuclear cage complex. The latter cage contains two types of metal ions, namely Rh3+ and Cu2+, showing significant characteristics of heterogeneous metal-assembling compounds. In addition, the cage accommodates two free isopropyl ether solvent molecules, thus displaying host–guest behavior.

Analysis of four polycyclic aromatic hydrocarbons in plant-based food supplements—results of a collaborative study

The determination of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in food supplements is challenging, especially due to the presence of other e.g. heterogeneous PAH-like compounds in the matrix. A collaborative study with 12 participants was conducted in order to assess performance characteristics of a fast method intended to analyse the four regulated PAHs (PAH 4) benzo[b]fluoranthene [BbF], benz[a]anthracene [BaA], chrysene [CHR] and benzo[a]pyrene [BaP] in five different plant-based food supplements in the form of capsules, powder, and tablets. The principle of the method includes the extraction of PAHs with ethyl acetate: cyclohexane followed by a two-step SPE cleanup and final analysis by GC-MS or LC-FLD. The regulated maximum level for BaP is 10 µg/kg and, for the PAH 4, 50 µg/kg. Accordingly, the method was validated for the regulated PAH 4 analytically challenging concentration range from 2.5 µg/kg to 6.9 µg/kg. The performance criteria for the method set in European Regulation No 333/2007 for the overall repeatability, reproducibility (HorRat values below 2), and recovery (range 50–120%) were fulfilled. Based on the statistical evaluation of the results, it was concluded that the method is a suitable alternative to existing methods and should be studied for additional matrices.

Synthesis and Characterization of New Coumarin Derivatives

New Schiff base compounds 3-acetyl-2-oxo-2H-chromen-7-yl-4(alkyloxy) benzoate thiosem icarbazide have been synthesized from the reaction between thiosemicarbazide and substituted coumarin. Target compound were characterized by FT-IR and NMR techniques heterogeneous coumarin compound. The result confirms the structure as suggested

Analysis of lorlatinib analogs reveals a roadmap for targeting diverse compound resistance mutations in ALK-positive lung cancer.

Lorlatinib is currently the most advanced, potent and selective anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor for the treatment of ALK-positive non-small cell lung cancer in the clinic; however, diverse compound ALK mutations driving therapy resistance emerge. Here, we determine the spectrum of lorlatinib-resistant compound ALK mutations in patients, following treatment with lorlatinib, the majority of which involve ALK G1202R or I1171N/S/T. We further identify structurally diverse lorlatinib analogs that harbor differential selective profiles against G1202R versus I1171N/S/T compound ALK mutations. Structural analysis revealed increased potency against compound mutations through improved inhibition of either G1202R or I1171N/S/T mutant kinases. Overall, we propose a classification of heterogenous ALK compound mutations enabling the development of distinct therapeutic strategies for precision targeting following sequential tyrosine kinase inhibitors.

Effect of Ag interlayer on friction torque, mechanical properties and microstructure of large diameter aluminum/steel joints by continuous drive friction welding

The large diameter aluminum/steel continuous driven friction welding component is prone to overload of the main motor due to high friction torque in the welding process. Therefore, multistage friction is used in industrial production to avoid overloading the main motors. However, multistage friction usually increases the heat input in the welding process and leads to the formation of thick and heterogeneous FeAl intermetallic compounds at the welding interface, which degrades the mechanical properties of the joints. Adding an Ag interlayer to the aluminum/steel interface can reduce the friction torque in the welding process, inhibit the interdiffusion of FeAl elements and reduce the thickness of FeAl intermetallic compounds. In this study, Q235 low-carbon steel rods (Diameter of weld end = 120 mm) with/without Ag interlayer and 1060 pure aluminum rods (Diameter of weld end = 90 mm) were welded by continuous drive friction welding. Voltage and Current of Major Motor (VCMM) in the welding process were processed and analyzed. The effects of the Ag interlayer on friction torque, mechanical properties of the post-weld joint and microstructure at the welding interface were analyzed. The research shows that the Ag interlayer can effectively reduce the initial peak torque and joint temperature in the welding process. The mechanical properties and intermetallic compound thickness of the post-weld joint still exhibit heterogeneity along the radial direction. The strength and toughness are significantly improved in the region of 0.5– 0.8R from the center, which is because the Ag2Al and Ag3Al phases with better toughness are formed in this region due to the change of the flow form of the interfacial viscoplastic metal by the Ag interlayer.

Are Inflamed Periodontal Tissues Endogenous Source of Advanced Glycation End-Products (AGEs) in Individuals with and without Diabetes Mellitus? A Systematic Review.

Advanced glycation end-products (AGEs) are heterogeneous compounds formed when excess sugars condense with the amino groups of nucleic acids and proteins. Increased AGEs are associated with insulin resistance and poor glycemic control. Recently, inflamed periodontal tissues and certain oral bacteria were observed to increase the local and systemic AGE levels in both normoglycemic and hyperglycemic individuals. Although hyperglycemia induced AGE and its effect on the periodontal tissues is known, periodontitis as an endogenous source of AGE formation is not well explored. Hence, this systematic review is aimed to explore, for the first time, whether inflamed periodontal tissues and periodontal pathogens have the capacity to modulate AGE levels in individuals with or without T2DM and how this affects the glycemic load. Six electronic databases were searched using the following keywords: (Periodontitis OR Periodontal disease OR Periodontal Inflammation) AND (Diabetes mellitus OR Hyperglycemia OR Insulin resistance) AND Advanced glycation end products. The results yielded 1140 articles, of which 13 articles were included for the review. The results showed that the mean AGE levels in gingival crevicular fluid was higher in individuals with diabetes mellitus and periodontitis (521.9 pg/mL) compared to healthy individuals with periodontitis (234.84 pg/mL). The serum AGE levels in normoglycemic subjects having periodontitis was higher compared to those without periodontitis (15.91 ng/mL vs. 6.60 ng/mL). Tannerella forsythia, a common gram-negative anaerobe periodontal pathogen in the oral biofilm, was observed to produce methylglyoxal (precursor of AGE) in the gingival tissues. Increased AGE deposition and activate of AGE receptors was noted in the presence of periodontitis in both normoglycemic and hyperglycemic individuals. Hence, it can be concluded that periodontitis can modulate the local and systemic levels of AGE levels even in absence of hyperglycemia. This explains the bidirectional relationship between periodontitis and development of prediabetes, incident diabetes, poor glycemic control, and insulin resistance.

A simple approach for prediction of Henry’s law constant of pesticides, solvents, aromatic hydrocarbons, and persistent pollutants without using complex computer codes and descriptors

A novel approach is introduced for reliable prediction of Henry’s law constant of persistent pollutants, pesticides, aromatic hydrocarbons, and solvents, which have extensive use for the description of the movement of chemical compounds inside and outside aquatic ecosystems. The largest available experimental data of Henry’s law constant for 530 heterogeneous chemicals are used to develop and test the novel model. This method needs the molecular structure of the chosen heterogeneous compound that is based on four non-additive factors including the contributions of hydrogen bonding functional groups, polar groups, halogenated compounds, hydrocarbons as well as the number of specific atoms as additive parameters. Internal and external validations are done on the estimated results for 353 and 177 chemicals of training and test sets, respectively. Various statistical parameters containing correlation coefficient (R2), the maximum value of errors (MaxError), mean error (ME), and root mean squared error (RMSE) are also used to confirm the high reliability of the novel correlation as compared with the best existing method, which requires complicated descriptors. The values of training set R2, MaxError, ME, and RMSE for the new/comparative models are 0.9512/0.8622, 1.521/4.417, 0.0000/0.0194, and 0.4632/0.7797, respectively. The same trend the mentioned statistical parameters also exists for the test set, which confirms the new correlation has higher reliability, goodness-of-fit, accuracy, and precision in comparison to the best available method.

Front Cover: Crystal Structures of Iron‐Based Oxides and Their Catalytic Efficiencies for the Oxygen Evolution Reaction: A Trend in Alkaline Media (ChemElectroChem 9/2022)

The Front Cover illustrates that artificial intelligence facilitates the understanding of science in electrocatalysis on heterogeneous crystalline compounds. Machine learning method demonstrates that alkaline oxygen evolution reaction on iron-based multimetal oxides is uniquely controlled by a structural descriptor, Fe–O bond length, and the trend is generally applicable regardless of chemical compositions, valence states of iron and structural categories of the crystals. More information can be found in the Research Article by Y. Sugawara et al.

Natural Compounds as Promising Adjuvant Agents in The Treatment of Gliomas.

In humans, glioblastoma is the most prevalent primary malignant brain tumor. Usually, glioblastoma has specific characteristics, such as aggressive cell proliferation and rapid invasion of surrounding brain tissue, leading to a poor patient prognosis. The current therapy—which provides a multidisciplinary approach with surgery followed by radiotherapy and chemotherapy with temozolomide—is not very efficient since it faces clinical challenges such as tumor heterogeneity, invasiveness, and chemoresistance. In this respect, natural substances in the diet, integral components in the lifestyle medicine approach, can be seen as potential chemotherapeutics. There are several epidemiological studies that have shown the chemopreventive role of natural dietary compounds in cancer progression and development. These heterogeneous compounds can produce anti-glioblastoma effects through upregulation of apoptosis and autophagy; allowing the promotion of cell cycle arrest; interfering with tumor metabolism; and permitting proliferation, neuroinflammation, chemoresistance, angiogenesis, and metastasis inhibition. Although these beneficial effects are promising, the efficacy of natural compounds in glioblastoma is limited due to their bioavailability and blood–brain barrier permeability. Thereby, further clinical trials are necessary to confirm the in vitro and in vivo anticancer properties of natural compounds. In this article, we overview the role of several natural substances in the treatment of glioblastoma by considering the challenges to be overcome and future prospects.

Furanic Humins from Biorefinery as Biobased Binder for Bitumen.

To decrease the environmental impact of bitumen, more sustainable binders should be proposed. This study emphasizes how industrial humins co-produced during the biorefining of carbohydrates can be employed as a macromolecular binder for bitumen. Humins are heterogeneous polyfuranic compounds, and they were mixed at 50 wt% with bitumen. When the non-water-soluble fractions of humins were employed (Hns), no variation of the chemical structure was observed in FTIR spectra after the mixing. The DSC investigations showed that the crystallization of aromatic fractions in bitumen shifted to higher temperature for humins’ modified bitumen. The thermogravimetric data highlighted that the presence of humins or Hns in bitumen can lead to mass loss below 200 °C. The rheological investigations highlighted some key advantages of using humins or Hns with bitumen. At high temperatures, the storage modulus of the modified bitumen is increased and shows lower susceptibility to variations in frequency. At low temperatures, the phase angle of Hns-modified bitumen is lower than that of bitumen, suggesting less temperature susceptibility as a consequence of a cross-linked network formation.

Comprehensive LC-MS/MS method combined with tandem hybrid hydrolysis for multiple exposure assessment of multiclass environmental pollutants

Environmental pollutants (EPOLs), such as phthalates, volatile organic compounds, phenols, parabens, polycyclic aromatic hydrocarbons, pyrethroids, and environmental tobacco smoke, are highly heterogeneous compounds. Recently, attention has been drawn to the assessment of the combinatory effects of multiple EPs. To correlate multiple exposures with potential health implications, advanced comprehensive analytical methods covering multiclass EPOLs are essential. However, because of several technical problems associated with enzyme hydrolysis, simultaneous extraction, and multiresidue liquid chromatography–tandem mass spectrometry analysis, it is difficult to establish a comprehensive method covering a number of EPOLs in a single sample preparation and analytical run. We developed tandem hybrid hydrolysis, modified direct injection, and a comprehensive mobile phase to overcome these technical problems and established a comprehensive analytical method for simultaneous biomonitoring of multiclass EPOLs. Tandem hybrid hydrolysis using β-glucuronidase and consecutive acid hydrolysis allowed selective hydrolysis of glucuronide- and sulfate-conjugated metabolites without phthalate degradation. The comprehensive mobile phase composed of 0.01% acetic acid and acetonitrile enabled us to simultaneously analyze 86 EPOLs, with good chromatographic behavior and ionization efficiency. Modified direct injection allowed a small amount of sample and simultaneous urinary extraction. The method was validated and applied to 39 urine samples from 19 mother–newborn pairs for multiple exposure assessment. Results showed that BP-3, a general component in sunblock products, and monoethyl phthalate, a metabolite of diethyl phthalate, exhibit a clear positive correlation between mothers and newborns. Therefore, the developed method has potential as a novel analytical tool for long-term, large-scale, and data-rich human biomonitoring of EPOLs.

PROTOTYPE OF HEXAGONAL PHOTO-REACTOR FOR DEGRADATION HUMIC ACID USING CU-ZNO AS A CATALYST IN VISIBLE LIGHTS

Humic acid is a heterogeneous organic compound that is carcinogenic in peat water and is very difficult to degrade biologically. Water is a source of life, therefore the need for clean water is increasing. This study aims to carry out the degradation of humic acid using the photocatalytic method. Photocatalysis is the degradation of humic acid using light in the presence of a photocatalyst in the reaction process. The photocatalyst used in this study was 7% Cu doped ZnO. The Cu doped ZnO used with a band gap of 2.57 eV and a particle size of 27 nm. In this study, the humic acid degradation process used a hexagonal photo reactor with various stirring speeds of 500, 1000, 1500 rpm and without stirring. The degradation process is carried out using outdoor light (direct sun). The light intensity can be measured using lightmeters on the front and rear of the reactor. The degradation process uses variations in irradiation time of 1, 2, 3, 4 and 5 hours. The degradation results were measured using a UV-Vis spectrophotometer to see the absorbance before and before degradation. The results of this study obtained the highest percentage degradation at the speed of each stirring of 500 rpm of 90.09% at 5 hours of irradiation, 1000 rpm of 97.37% at 5 hours of irradiation, 1500 rpm of 97.79% at 5 hours of irradiation. hours and without stirring of 71.71% at 5 hours of irradiation. The maximum degradation concentration in this study was obtained at a stirring speed of 1500 rpm and an irradiation time of 5 hours. The speed and irradiation time have an influence on the degradation results obtained.

PFAS Molecules: A Major Concern for the Human Health and the Environment.

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4700 heterogeneous compounds with amphipathic properties and exceptional stability to chemical and thermal degradation. The unique properties of PFAS compounds has been exploited for almost 60 years and has largely contributed to their wide applicability over a vast range of industrial, professional and non-professional uses. However, increasing evidence indicate that these compounds represent also a serious concern for both wildlife and human health as a result of their ubiquitous distribution, their extreme persistence and their bioaccumulative potential. In light of the adverse effects that have been already documented in biota and human populations or that might occur in absence of prompt interventions, the competent authorities in matter of health and environment protection, the industries as well as scientists are cooperating to identify the most appropriate regulatory measures, substitution plans and remediation technologies to mitigate PFAS impacts. In this review, starting from PFAS chemistry, uses and environmental fate, we summarize the current knowledge on PFAS occurrence in different environmental media and their effects on living organisms, with a particular emphasis on humans. Also, we describe present and provisional legislative measures in the European Union framework strategy to regulate PFAS manufacture, import and use as well as some of the most promising treatment technologies designed to remediate PFAS contamination in different environmental compartments.

Dual regulation of lipid droplet-triacylglycerol metabolism and ERG9 expression for improved \u03b2-carotene production in Saccharomyces cerevisiae

BackgroundThe limitation of storage space, product cytotoxicity and the competition for precursor are the major challenges for efficiently overproducing carotenoid in engineered non-carotenogenic microorganisms. In this work, to improve β-carotene accumulation in Saccharomyces cerevisiae, a strategy that simultaneous increases cell storage capability and strengthens metabolic flux to carotenoid pathway was developed using exogenous oleic acid (OA) combined with metabolic engineering approaches.ResultsThe direct separation of lipid droplets (LDs), quantitative analysis and genes disruption trial indicated that LDs are major storage locations of β-carotene in S. cerevisiae. However, due to the competition for precursor between β-carotene and LDs-triacylglycerol biosynthesis, enlarging storage space by engineering LDs related genes has minor promotion on β-carotene accumulation. Adding 2 mM OA significantly improved LDs-triacylglycerol metabolism and resulted in 36.4% increase in β-carotene content. The transcriptome analysis was adopted to mine OA-repressible promoters and IZH1 promoter was used to replace native ERG9 promoter to dynamically down-regulate ERG9 expression, which diverted the metabolic flux to β-carotene pathway and achieved additional 31.7% increase in β-carotene content without adversely affecting cell growth. By inducing an extra constitutive β-carotene synthesis pathway for further conversion precursor farnesol to β-carotene, the final strain produced 11.4 mg/g DCW and 142 mg/L of β-carotene, which is 107.3% and 49.5% increase respectively over the parent strain.ConclusionsThis strategy can be applied in the overproduction of other heterogeneous FPP-derived hydrophobic compounds with similar synthesis and storage mechanisms in S. cerevisiae.Graphical