Investigating the Quality and Purity Profiles of Olive Oils from Diverse Regions in Selçuk, Izmir.

The Selçuk district of Izmir is one of the most essential regions in terms of olive oil production. In this study, 60 olive oil samples were obtained from five different locations (ES: Eski Sirince Yolu, KK: Kinali Köprü, AU: Abu Hayat Üst, AA: Abu Hayat Alt, and DB: Degirmen Bogazi) in the Selçuk region of Izmir during two (2019-2020 and 2020-2021) consecutive cropping seasons. Quality indices (free acidity, peroxide value, p-Anisidine value, TOTOX, and spectral absorption at 232 and 270 nm) and the fatty acid, phenolic, and sterol profiles of the samples were determined to analyze the changes in the composition of Selcuk olive oils according to their growing areas. When the quality criteria were analyzed, it was observed that KK had the lowest FFA (0.11% oleic acid, PV (6.66 meq O2/kg), p-ANV (11.95 mmol/kg), TOTOX (25.28), and K232 (1.99) values and K270 had the highest value. During the assessment of phenolic profiles, the ES group exhibited the highest concentration of the phenolic compound p-HPEA-EDA (oleocanthal), with a content of 93.58 mg/kg, equivalent to tyrosol. Upon analyzing the fatty acid and sterol composition, it was noted that AU displayed the highest concentration of oleic acid (71.98%) and ß-sitosterol (87.65%). PCA analysis illustrated the distinct separation of the samples, revealing significant variations in both sterol and fatty acid methyl ester distributions among oils from different regions. Consequently, it was determined that VOOs originating from the Selçuk region exhibit distinct characteristics based on their geographical locations. Hence, this study holds great promise for the region to realize geographically labeled VOOs.

Sterol Migration during Rotational Frying of Food Products in Modified Rapeseed and Soybean Oils.

This study explores the impact of rotational frying of three different food products on degradation of sterols, as well as their migration between frying oils and food. The research addresses a gap in the existing literature, which primarily focuses on changes in fat during the frying of single food items, providing limited information on the interaction of sterols from the frying medium with those from the food product. The frying was conducted at 185 ± 5 °C for up to 10 days where French fries, battered chicken, and fish sticks were fried in succession. The sterol content was determined by Gas Chromatography. This research is the first to highlight the influence of the type of oil on sterol degradation in both oils and food. Notably, sterols were found to be most stable when food products were fried in high-oleic low-linolenic rapeseed oil (HOLLRO). High-oleic soybean oil (HOSO) exhibited higher sterol degradation than high-oleic rapeseed oil (HORO). It was proven that cholesterol from fried chicken and fish sticks did not transfer to the fried oils or French fries. Despite initially having the highest sterol content in fish, the lowest sterol amount was recorded in fried fish, suggesting rapid degradation, possibly due to prefrying in oil with a high sterol content, regardless of the medium used.

Stable Carbon Isotope Ratios (δ13C Values [‰]) of Individual Sterols in the Oils of C3, C4, and CAM Plants.

The compound-specific determination of δ13C values [‰] by gas chromatography interfaced with isotope ratio mass spectrometry (GC-IRMS) is a powerful analytical method to indicate minute but relevant variations in the 13C/12C ratio of sample compounds. In this study, the δ13C values [‰] of individual sterols were measured in eleven different oils of C3, C4, and CAM plants (n = 33) by GC-IRMS. For this purpose, a suitable acetylation method was developed for sterols. Nine of the eleven phytosterols identified by GC with mass spectrometry (GC/MS) could be measured by GC-IRMS. The δ13C values [‰] of individual sterols and squalene of C3 plant oils were between 3‰ and >16‰ more negative (lighter in carbon) than in C4 and CAM oils. We also showed that the blending of C4 oils into C3 oils (exemplarily conducted with one olive and one corn oil) would be precisely determined by means of the δ13C value [‰] of ß-sitosterol.

Metabolite profiling and histochemical localization of alkaloids in Hippeastrum papilio (Ravena) van Scheepen.

Hippeastrum papilio (Amaryllidaceae) is a promising new source of galanthamine - an alkaloid used for the cognitive treatment of Alzheimer's disease. The biosynthesis and accumulation of alkaloids are tissue - and organ-specific. In the present study, histochemical localization of alkaloids in H. papilio's plant organs with Dragendorff's reagent, revealed their presence in all studied samples. Alkaloids were observed in vascular bundles, vacuoles, and intracellular spaces, while in other plant tissues and structures depended on the plant organ. The leaf parenchyma and the vascular bundles were indicated as alkaloid-rich structures which together with the high proportion of alkaloids in the phloem sap (49.3% of the Total Ion Current - TIC, measured by GC-MS) indicates the green tissues as a possible site of galanthamine biosynthesis. The bulbs and roots showed higher alkaloid content compared to the leaf parts. The highest alkaloid content was found in the inner bulb part. GC-MS metabolite profiling of H. papilio's root, bulb, and leaves revealed about 82 metabolites (>0.01% of TIC) in the apolar, polar, and phenolic acid fractions, including organic acids, fatty acids, sterols, sugars, amino acids, free phenolic acids, and conjugated phenolic acids. The most of organic and fatty acids were in the peak part of the root, while the outermost leaf was enriched with sterols. The outer and middle parts of the bulb had the highest amount of saccharides, while the peak part of the middle leaf had most of the amino acids, free and conjugated phenolic acids.

Differential regulation of key triterpene synthase gene under abiotic stress in Withania somnifera L. Dunal and its co-relation to sterols and withanolides.

Withania somnifera (Ashwagandha), is one of the most reputed Indian medicinal plants, having immense pharmacological activities due to the occurrence of withanolides. The withanolides are biosynthesized through triterpenoid biosynthetic pathway with the involvement of WsCAS leading to cyclization of 2, 3 oxidosqualene, which is a key metabolite to further diversify to a myriad of phytochemicals. In contrast to the available reports on the studies of WsCAS in withanolide biosynthesis, its involvement in phytosterol biosynthesis needs investigation. Present work deals with the understanding of role of WsCAS triterpenoid synthase gene in the regulation of biosynthesis of phytosterols & withanolides. Docking studies of WsCAS protein revealed Conserved amino acids, DCATE motif, and QW motif which are involved in efficient substrate binding, structure stabilization, and catalytic activity. Overexpression/silencing of WsCAS leading to increment/decline of phytosterols confers its stringent regulation in phytosterols biosynthesis. Differential regulation of WsCAS on the metabolic flux towards phytosterols and withanolide biosynthesis was observed under abiotic stress conditions. The preferential channelization of 2, 3 oxidosqualene towards withanolides and/or phytosterols occurred under heat/salt stress and cold/water stress, respectively. Stigmasterol and ß-sitosterol showed major contribution in high/low temperature and salt stress, and campesterol in water stress management. Overexpression of WsCAS in Arabidopsis thaliana led to the increment in phytosterols in general. Thus, the WsCAS plays important regulatory role in the biosynthetic pathway of phytosterols and withanolides under abiotic stress conditions.

A Review of Recent Progresses on Olive Oil Chemical Profiling, Extraction Technology, Shelf-life, and Quality Control.

Olive oil (OO) is widely recognized as a main component in the Mediterranean diet owing to its unique chemical composition and associated health-promoting properties. This review aimed at providing readers with recent results on OO physicochemical profiling, extraction technology, and quality parameters specified by regulations to ensure authentic products for consumers. Recent research progress on OO adulteration were outlined through a bibliometric analysis mapping using Vosviewer software. As revealed by bibliometric analysis, richness in terms of fatty acids, pigments, polar phenolic compounds, tocopherols, squalene, sterols, and triterpenic compounds justify OO health-promoting properties and increasing demand on its global consumption. OO storage is a critical post-processing operation that must be optimized to avoid oxidation. Owing to its great commercial value on markets, OO is a target to adulteration with other vegetable oils. In this context, different chemometric tools were developed to deal with this problem. To conclude, increasing demand and consumption of OO on the global market is justified by its unique composition. Challenges such as oxidation and adulteration stand out as the main issues affecting the OO market.

Diosgenin biosynthesis pathway and its regulation in Dioscorea cirrhosa L.

Dioscorea cirrhosa L. (D. cirrhosa) tuber is a traditional medicinal plant that is abundant in various pharmacological substances. Although diosgenin is commonly found in many Dioscoreaceae plants, its presence in D. cirrhosa remained uncertain. To address this, HPLC-MS/MS analysis was conducted and 13 diosgenin metabolites were identified in D. cirrhosa tuber. Furthermore, we utilized transcriptome data to identify 21 key enzymes and 43 unigenes that are involved in diosgenin biosynthesis, leading to a proposed pathway for diosgenin biosynthesis in D. cirrhosa. A total of 3,365 unigenes belonging to 82 transcription factor (TF) families were annotated, including MYB, AP2/ERF, bZIP, bHLH, WRKY, NAC, C2H2, C3H, SNF2 and Aux/IAA. Correlation analysis revealed that 22 TFs are strongly associated with diosgenin biosynthesis genes (-r2- > 0.9, P < 0.05). Moreover, our analysis of the CYP450 gene family identified 206 CYP450 genes (CYP450s), with 40 being potential CYP450s. Gene phylogenetic analysis revealed that these CYP450s were associated with sterol C-22 hydroxylase, sterol-14-demethylase and amyrin oxidase in diosgenin biosynthesis. Our findings lay a foundation for future genetic engineering studies aimed at improving the biosynthesis of diosgenin compounds in plants.

A metabolomics approach for the evaluation of Ficus benghalensis female in vivo reproductive effects relative to its metabolite fingerprint as determined via UPLC-MS and GC-MS.

ETHNOPHARMACOLOGICAL RELEVANCE: Ficus benghalensis, commonly known as Banyan Fig, is the national tree of India and its aerial roots are used traditionally to treat female reproductive disorders. However, despite this traditional use, no pharmacological evidence could be traced supporting this use. Additionally, no comprehensive metabolite profiling was reported for F. benghalensis aerial roots. AIM OF THE STUDY: This study attempts to justify biochemically the traditional use of F. benghalensis aerial roots in treatment of female reproductive disorders and in relation to its secondary metabolite profile. MATERIALS AND METHODS: Total ethanol extract (TEE) and subfractions [petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF) and n-butanol (BUF] were prepared from air-dried powdered aerial roots of F. benghalensis. Detailed in-vivo investigation of the hormonal activity and action mechanism of the total ethanol extract and subfractions was carried out through evaluation of estrogenic and gonadotropic activities. The estrogenic activity was evaluated on ovariectomized immature female rats through estimating uterine weight, vaginal cornification and serum estradiol level along with histological examination of uteri. The gonadotropic activity was measured by assay of follicle stimulating hormone (FSH) and luteinizing hormone (LH) like activities. Total follicular and corpora lutea counts in immature female rats were used to determine FSH and LH like activities, respectively in addition to histological picture of the genitalia. Comprehensive non-targeted metabolite profiling was carried out for the TEE and subfractions using UPLC-HRMS in negative and positive ionization modes. UPLC-MS fingerprint was subjected to principal component analysis (PCA) and partial least squares analyses to correlate the bioactivities to specific chemical constituents in F. benghalensis different subfractions. GC-MS was further used for non-polar silylated fractions. RESULTS: Results revealed that only the non-polar PEF and CHF displayed moderate estrogenic and FSH-like activities but with no LH-like activity. Metabolites profiling via (UPLC-HRMS) and multivariate PCA analysis enabled identification and comparison of various chemical classes in F. benghalensis extract and fractions. The active non-polar fractions revealed nearly similar metabolites profile being composed of isoflavonoids, triterpenes, sterols, fatty acids and cyclic peptides. In contrast, polar fractions were more abundant in apocarotenoids, fatty acyl amides, hydroxybenzoates and hydroxycinnamates in addition to two lignans. PLS analysis revealed strong correlation between hydroxylated fatty acids and pyranoisoflavones with estrogenic and FSH-like activities. GC-MS analysis was further employed for non-polar fractions profiling revealing for their enrichment in fatty acids/esters, terpenes, organic acids and phenolics. CONCLUSION: This is the first study to rationalize the use of F. benghalensis aerial root traditionally in treatment of gynecological disorders, revealing that the petroleum ether and chloroform non-polar subfractions of F. benghalensis showed estrogenic and FSH-like activity with absence of LH-like activity. This biological activity could possibly be attributed to its metabolites profile of isoflavonoids, fatty acids, triterpenes, sterols and cyclic peptides identified via UPLC-MS and GC-MS techniques. Consequently, F. benghalensis aerial roots should be used with caution in traditional treatment of female infertility or other reproductive disorders.

Effect of enzymatic Maillard reaction conditions on physicochemical properties, nutrition, fatty acids composition and key aroma compounds of fragrant rapeseed oil.

BACKGROUND: A new enzymatic hydrolysis-based process inspired by the Maillard reaction can produce strong flavored, high-value rapeseed oil that meets safety requirements. In the present study, the effect of reaction time (10-30 min) and temperature (130-160 °C) on the physicochemical properties, nutritional status, fatty acids composition and key aroma compounds of fragrant rapeseed oil (FRO) was investigated. RESULTS: An increasing reaction time and temperature substantially decreased the total tocopherol, polyphenol and sterol contents of FRO, but increased benzo[a]pyrene content, as well as the acid and peroxide values, which did not exceed the European Union legislation limit. Among the volatile components, 2,5-dimethyl was the main substance contributing to the barbecue flavor of FRO. The 150 °C for 30 min reaction conditions produced a FRO with a strong, fragrant flavor, with high total tocopherol (560.15 mg kg-1 ), polyphenol (6.82 mg kg-1 ) and sterol (790.65 mg kg-1 ) contents; acceptable acid (1.60 mg g-1 ) and peroxide values (4.78 mg g-1 ); and low benzo[a]pyrene (1.39 mg g-1 ) content. These were the optimal conditions for the enzymatic Maillard reaction, according to the principal component analysis. Furthermore, hierarchical cluster analysis showed that reaction temperature had a stronger effect on FRO than reaction time. CONCLUSION: The optimal enzymatic Maillard reaction conditions for the production of FRO are heating at 150 °C for 30 min. These findings provide new foundations for better understanding the composition and flavor profile of FRO, toward guiding its industrial production. © 2023 Society of Chemical Industry.

Effects of Fermented Extracts of Wuniuzao Dark Loose Tea on Hepatic Sterol Regulatory Element-Binding Protein Pathway and Gut Microbiota Disorder in Obese Mice.

BACKGROUND: Artificially fermented dark loose tea is a type of novel dark tea prepared via fermentation by Eurotium cristatum. The effects of artificially fermented dark loose tea on lipid metabolism are still unclear. OBJECTIVES: This study aimed to explore if artificially fermented dark loose tea has the same effects as naturally fermented dark loose tea in regulating hepatic lipid metabolism. METHODS: Thirty-six 8-wk-old male C57BL/6 mice were randomly divided into 6 treatment groups, including normal control (NC), high-fat diet (HFD), positive control (PC), Wuniuzao dark raw tea (WDT), Wuniuzao naturally fermented dark loose tea (NFLT), and Wuniuzao artificially fermented dark loose tea (AFLT) groups. The HFD, PC, WDT, NFLT, and AFLT groups were fed a HFD. The PC group was supplemented with atorvastatin (10 mg/kg). The WDT group was supplemented with WDT (300 mg/kg), the NFLT group with NFLT (300 mg/kg), and the AFLT group with AFLT (300 mg/kg). RESULTS: The study compared the effect of WDT, NFLT, and AFLT on liver steatosis and gut microbiota disorder in obese mice. All 3 tea extracts reduced body weight, glucose tolerance, and serum lipid concentrations. Via sterol-regulatory element binding protein (SREBP)-mediated lipid metabolism, all 3 tea extracts alleviated hepatic steatosis in mice with obesity. Furthermore, NFLT and AFLT intervened in the abundance of Firmicutes, Bacteroidetes, Clostridia, Muribaculaceae, and Lachnospiraceae. CONCLUSION: In mice with obesity induced by a HFD, WDT, NFLT, and AFLT may improve hepatic steatosis through an SREBP-mediated lipid metabolism. Moreover, NFLT and AFLT improved the composition of gut microbiota.

Anxiolytic interventions of extracts and pure compounds from Adenanthera pavonina and Peltophorum pterocarpum leaves to treat acute anxiety and depression symptoms in mice.

Anxiolytic effect of ethanol, hexane extracts and pure compounds ß- sito sterol glucoside and bergenin isolated from Adenanthera pavonina AP (Fabaceae) and Peltophorum pterocarpum PP (Fabaceae) leaves were monitored in this study. Mice were treated with dose of 125mg/kg body weight of ethanol and hexane leaves extracts of both tested plants while, 5mg/kg body weight of ß-sito sterol glucoside and 25mg/kg body weight of bergenin. The effect was monitored by hole board test, forced swimming test, open field apparatus and stationary rod test. Results from neuropharmacological effects revealed that ethanol extract of AP leaves and hexane extract of PP leaves had significant anxiolytic (forced swimming test) exploratory (head dip and open field test) and neuro activator activity (stationary rod test) at tested dose. The greatest anti-depressant and anxiolytic effect was found in ethanol extract of AP leaves when compared to all treated drugs. A part from memory enhancing effects, diazepam treated mice also exhibited anxiolytic and antidepressant effects and found comparable with ethanol extract of AP. These findings may clarify the impact of ethanol, hexane extracts and pure substances ß-sitosterol glucoside and bergenin at tested concentrations, as well as their potential to treat the Parkinson's and related disorders as an alternative therapy.

Application of Miscanthus substrates in the cultivation of Ganoderma lingzhi.

Ganoderma lingzhi is a traditional Chinese medicine that has been used to improve health and longevity for thousands of years. It is usually cultivated on hardwood log- or sawdust-based formulations. Conversely, in this study, we used Miscanthus sacchariflorus (MSF), M. floridulus, and M. sinensis (MSS), fast-growing perennial grasses widely distributed in China, for G. lingzhi cultivation. Mycelial growth rate, activities of lignin-degrading enzymes on colonized mushroom substrates, and expression levels of CAZymes and laccase genes based on different substrates were analyzed. Total triterpenoids, sterols, and polysaccharides content of fruiting bodies obtained from different substrates were investigated. The activities of laccase and manganese peroxidase in mycelia increased in the MSF- and MSS-based formulations compared with that in the sawdust-based formulation. The results of mycelial growth- and cultivation-related experiments showed that the Miscanthus substrates could be used as the substrates for cultivating G. lingzhi. The content of active ingredients, namely triterpenoids, sterols, and polysaccharides, in fruiting bodies cultivated on the Miscanthus substrates did not decrease compared with those in substrate obtained from the sawdust-based formulation. Therefore, the present study provides alternative substrates for the cultivation of G. lingzhi, and a reference for better utilization of inexpensive substrate in future.

In Situ Rapid Analysis of Squalene, Tocopherols, and Sterols in Walnut Oils Based on Supercritical Fluid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry.

Quantification of liposoluble micronutrients in large-scale vegetable oil samples is urgently needed, because their health benefits are increasingly emphasized. However, current analytical methods are limited to either labor-intensive preparation processes or time-consuming chromatography separation. In this work, an online oil matrix separation strategy for direct, rapid, and simultaneous determination of squalene, tocopherols, and phytosterols in walnut oil (WO) was developed on the basis of the lipid class separation mode of supercritical fluid chromatography. A single run was completed in 13 min containing 6 min of column cleaning and balancing. Satisfactory limit of detections (0.05-0.20 ng/mL), limit of quantifications (0.15-0.45 ng/mL), recoveries (70.61-101.44%), and matrix effects (78.43-91.62%) were achieved, indicating the reliability of this method. In addition, eight sterol esters were identified in WO, which have not previously been reported. The proposed method was applied to characterize the liposoluble micronutrient profile of WO samples obtained from different walnut cultivars, geographical origins, and processes.

Characterization of thraustochytrid-specific sterol O-acyltransferase: modification of DGAT2-like enzyme to increase the sterol production in Aurantiochytrium limacinum mh0186.

IMPORTANCE: Since the global market for sterols and vitamin D are grown with a high compound annual growth rate, a sustainable source of these compounds is required to keep up with the increasing demand. Thraustochytrid is a marine oleaginous microorganism that can synthesize several sterols, which are stored as SE in lipid droplets. DGAT2C is an unconventional SE synthase specific to thraustochytrids. Although the primary structure of DGAT2C shows high similarities with that of DGAT, DGAT2C utilizes sterol as an acceptor substrate instead of diacylglycerol. In this study, we examined more detailed enzymatic properties, intracellular localization, and structure-activity relationship of DGAT2C. Furthermore, we successfully developed a method to increase sterol and provitamin D3 productivity of thraustochytrid by more than threefold in the process of elucidating the function of the DGAT2C-specific N-terminal region. Our findings could lead to sustainable sterol and vitamin D production using thraustochytrid.

Sterol composition in plants is specific to pollen, leaf, pollination and pollinator.

Sterols have several roles in planta, including as membrane components. Sterols are also essential nutrients for insects. Based on this, and the different functions of leaves and pollen, we tested the hypotheses that (a) the sterolome is different in leaves and pollen from the same plant, (b) pollens from wind- and insect pollinated plants comprise different sterols, and (c) sterol provision in pollen-rewarding angiosperms differs from nectar-rewarding species. A novel approach to sterolomics was developed, using LCMS to determine the sterol profile of leaf and pollen from a taxonomically diverse range of 36 plant species. Twenty-one sterols were identified unambiguously, with several more identified in trace amounts. C29 sterols dominated the sterolome in most plants. The sterol composition was significantly different in leaf and pollen and their main sterols evolved in different ways. The sterolome of pollen from animal- and wind-pollinated was also significantly different, but not between nectar- and pollen-rewarding species. Our results suggest that the sterol composition in different plant tissues is linked to their biological functions. Sterol composition in pollen might be driven by physical role rather than the nutrient needs of pollinating insects.

Sterols Content of Fruiting Bodies of Medicinal Artist's Bracket Mushroom Ganoderma applanatum (Agaricomycetes) Collected in Armenia.

The qualitative analysis of hexane extracts obtained from different trama layers (WT, T1-T4) of dried fruiting bodies of medicinal bracket fungus Ganoderma applanatum collected in the Tavoush region of North-East Armenia was performed by GC-MS analysis. Three sterols [(7.22-ergostadienon, ergosterol and ergosta-14.22-diene-3-ol (3ß, 5α, 22E)] have been identified. The results have shown that the content and ratio of sterols differ in analyzed trama samples. The highest amount of sterols was detected in middle parts of T2 and T3 layers, while content of sterols gradually decreased to the upper cortical (T4) and lower hymenial (T1) layers. The chromatographic profiles of identified compounds indicate that different sterols dominated in each layer: 7.22-ergostadienon in T4, ergosterol in T3, T2, and T1. The average weight loss of analyzed trama samples during six days of drying was about 40 wt.% (37.0-43.49 wt.%) of the total weight of basidiome, which decreased up to 5 wt.% in the next two days. The complete extraction of sterols lasted six days. Its further prolongation leads to stationary phase without an increase in the amount of extracted sterols.

[Gene clone and functional identification of sterol glycosyltransferases from Paris polyphylla var. yunnanensis].

In this study, the authors cloned a glycosyltransferase gene PpUGT2 from Paris polyphylla var. yunnanensis with the ORF length of 1 773 bp and encoding 590 amino acids. The phylogenetic tree revealed that PpUGT2 belonged to the UGT80A subfamily and was named as UGT80A49 by the UDP-glycosyltransferase(UGT) Nomenclature Committee. The expression vector pET28a-PpUGT2 was constructed, and enzyme catalytic reaction in vitro was conducted via inducing protein expression and extraction. With UDP-glucose as sugar donor and diosgenin and pennogenin as substrates, the protein was found with the ability to catalyze the C-3 hydroxyl ß-glycosylation of diosgenin and pennogenin. To further explore its catalytic characteristic, 15 substrates including steroids and triterpenes were selected and PpUGT2 showed its activity towards the C-17 position of sterol testosterone with UDP-glucose as sugar donor. Homology modelling and molecule docking of PpUGT2 with substrates predicted the key residues interacting with ligands. The re-levant residues of PpUGT2-ligand binding model were scanned to calculate the corresponding mutants, and the optimized mutants were obtained according to the changes in binding affinity of the ligand with protein and the surrounding residues within 5.0 Å of ligands, which had reference value for design of the mutants. This study laid a foundation for further exploring the biosynthetic pathway of polyphyllin as well as the structure of sterol glycosyltransferases.

Bioprocess conditions and regulation factors to optimize squalene production in thraustochytrids.

Squalene is a widely distributed natural triterpene, as it is a key precursor in the biosynthesis of all sterols. It is a compound of high commercial value worldwide because it has nutritional, medicinal, pharmaceutical, and cosmetic applications, due to its different biological properties. The main source of extraction has been shark liver oil, which is currently unviable on a larger scale due to the impacts of overexploitation. Secondary sources are mainly vegetable oils, although a limited one, as they allow low productive yields. Due to the diversity of applications that squalene presents and its growing demand, there is an increasing interest in identifying sustainable sources of extraction. Wild species of thraustochytrids, which are heterotrophic protists, have been identified to have the highest squalene content compared to bacteria, yeasts, microalgae, and vegetable sources. Several studies have been carried out to identify the bioprocess conditions and regulation factors, such as the use of eustressors that promote an increase in the production of this triterpene; however, studies focused on optimizing their productive yields are still in its infancy. This review includes the current trends that also comprises the advances in genetic regulations in these microorganisms, with a view to identify the culture conditions that have been favorable in increasing the production of squalene, and the influences that both bioprocess conditions and applied regulation factors partake at a metabolic level.

Gas chromatography with mass spectrometry analysis of 4,4-dimethylsterols and 4-methylsterols in edible oils after their enrichment by means of solid phase extraction.

4-Methylsterols (4-M-sterols) and 4,4-dimethylsterols (4,4-D-sterols) are a group of underexplored minor sterols that occur in almost all living organisms. Here, we developed a strategy for the determination of the biochemical precursors of the predominant 4-desmethylsterols in edible oils. Due to their low contribution to the sterol content in the samples, a solid phase extraction (SPE) method was developed for the enrichment of 4-M- and 4,4-D-sterols in the hexane extracts of saponified oils. In a two-fold SPE procedure, the bulk of 4,4-D-sterols was collected in one fraction. The residual sample was subjected to a second SPE step which targeted all 4-M-sterols and low shares of 4,4-D-sterols in one fraction and the predominant 4-desmethylsterols in another one. After silylation of the SPE fractions, gas chromatography with mass spectrometry (GC/MS) was used to analyze 4,4-D- and 4-M-sterols. The results were used to define eight subgroups whose characteristic structural features could be linked with the presence of specific m/z values. These m/z values were measured sensitively by GC/MS operated in selected ion monitoring (SIM) mode. Application of the GC/MS method to eighteen edible oils enabled the detection of 55 mostly very low abundant 4-M- and 4,4-D-sterols. Twenty-four of the 4-M- and 4,4-D-sterols could be assigned and the remaining 31 unknown sterols could be traced back to their basic structures.

The Impact of Cholecaciferol Supplementation on Bone Mineral Density in Long-Term Kidney Transplant Recipients.

Although reduced bone mineral density (BMD) is associated with a higher risk of fractures, morbidity, and mortality in kidney transplant patients (KTRs), there is no consensus on optimal treatment for the alterations of BMD in this population. This study aims at assessing the effect of cholecalciferol supplementation on BMD over a follow-up period of 2 years in a cohort of long-term KTRs. Patients with age ≥ 18 years were included and divided into two subgroups based on treatment with bisphosphonate and/or calcimimetics and/or active vitamin D sterols (KTRs-treated) or never treated with the above medications (KTRs-free). BMD was evaluated at lumbar vertebral bodies (LV) and right femoral neck (FN) with standard DEXA at the beginning and end of the study. According to World Health Organization (WHO) criteria, results were expressed as T-score and Z-score. Osteoporosis and osteopenia were defined as T score ≤ -2.5 SD and T score < -1 and >-2.5 SD, respectively. Cholecalciferol was supplemented at a dose of 25,000 IU/week over 12 weeks followed by 1500 IU/day. KTRs-free (n. 69) and KTRs-treated (n. 49) consecutive outpatients entered the study. KTRs-free were younger (p < 0.05), with a lower prevalence of diabetes (p < 0.05) and of osteopenia at FN (46.3 % vs. 61.2 %) compared to KTRs-treated. At the entry none of the study subjects had a sufficient level of cholecalciferol; Z-score and T-score at LV and FN were not different between groups. At the end of the study period, serum cholecalciferol concentration was significantly increased in both groups (p < 0.001); the KTRs-free group presented an improvement in both T-score and Z-score at LV (p < 0.05) as well as a lower prevalence of osteoporotic cases (21.7% vs. 15.9%); in contrast, no changes were recorded in KTR-treated individuals. In conclusion, supplementation with cholecalciferol ameliorated Z-score and T-score at LV in long-term KTRs who had been never treated with active or inactive vitamin D sterols, bisphosphonates, and calcimimetics. Future endeavours are needed to confirm these preliminary findings.