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1,5-Disubstituted bicyclo[2.1.1]hexanes are bridged scaffolds with well-defined exit vectors that are becoming increasingly popular building blocks in medicinal chemistry because they are saturated bioisosteres of ortho -substituted phenyl rings. Here we have developed a Lewis-acid-catalysed [2 + 2] photocycloaddition to obtain these motifs as enantioenriched scaffolds, providing an efficient approach for their incorporation in a variety of drug analogues. Retention of the biological activity of the bicyclo[2.1.1]hexane-containing analogues in the specific proteins targeted by the original drugs has confirmed the suitability of this moiety to serve as a bioisostere of ortho -substituted phenyl rings. Moreover, we have studied the potential of the different enantiomers of the drug analogues to selectively induce cytotoxicity in a panel of tumour cell lines, observing markedly differential effects for the two enantiomers and a substantial improvement over the corresponding sp 2 -based drugs. This showcases that the control of the absolute configuration and tridimensionality of the drug analogue has a large impact on its biological properties. The incorporation of saturated bioisosteres of phenyl rings has emerged as an appealing strategy in drug-discovery programmes. However, stereocontrolled access to these sp 3 -hybridized skeletons remains elusive. Now, the enantioselective synthesis of bicyclo[2.1.1]hexanes has been achieved through a Lewis-acid-catalysed [2 + 2] photocycloaddition, making it possible to obtain different drug analogues with improved properties.

Frankincense ( Boswellia spp.) oleogum resin is a valuable natural source of bioactive phytoconstituents with diverse therapeutic potential. In this study, the hydrodistilled essential oil (EO) and n -hexane extract (HE) of Boswellia serrata gums were analyzed through gas chromatography–mass spectrometry (GC-MS) to determine their phytochemical composition. The GC-MS results in the identification of 62 and 71 components in the EO and HE, respectively. Acetic acid octyl ester (41.09%) and nerolidol (13.64%), were the major components of the EO. Meanwhile, incensole (28.56%), (1S,2E,4S,5R,7E,11E)-cembra-2,7,11-trien-4,5-diol (13.54%), and 24-norursa-3,12-diene (9.25%) in the HE. Regarding the antioxidant effects, the EO exhibited significantly higher antioxidant capacity compared to the HE (DPPH: 9.24 and 6.50 mg TE/g; ABTS: 25.71 and 4.94 mg TE/g), respectively. Moreover, the EO was more potent in the CUPRAC test (61.12 mg TE/g for the essential oil and 50.62 mg TE/g for HE), while the n -hexane extract (72.68 mg TE/g) showed stronger ability than the EO (13.22 mg TE/g) in the FRAP assay. The EO had a higher ability in phosphomolybdenum and metal chelation tests in comparison with the HE extracts. Further, the oil showed more potent inhibitory activity against cholinesterase, α -glucosidase, and tyrosinase than the HE extract. The HE extract was only more active on α -amylase compared to the oil. These findings suggest that olibanum EO possesses potent bioactive compounds that may contribute to the management of oxidative stress and age-related conditions, including Alzheimer’s disease, diabetes mellitus, and skin hyperpigmentation.

Hexane is a solvent used extensively in the food industry for the extraction of various products such as vegetable oils, fats, flavours, fragrances, colour additives or other bioactive ingredients. As it is classified as a “processing aid”, it does not have to be declared on the label under current legislation. Therefore, although traces of hexane may be found in final products, especially in processed products, its presence is not known to consumers. However, hexane, and in particular the n-hexane isomer, has been shown to be neurotoxic to humans and has even been listed as a cause of occupational diseases in several European countries since the 1970s. In order to support the European strategy for a toxic-free environment (and toxic-free food), it seemed important to collect scientific information on this substance by reviewing the available literature. This review contains valuable information on the nature and origin of the solvent hexane, its applications in the food industry, its toxicological evaluation and possible alternatives for the extraction of natural products. Numerous publications have investigated the toxicity of hexane, and several studies have demonstrated the presence of its toxic metabolite 2,5-hexanedione (2,5-HD) in the urine of the general, non-occupationally exposed population. Surprisingly, a tolerable daily intake (TDI) has apparently never been established by any food safety authority. Since hexane residues are undoubtedly found in various foods, it seems more than necessary to clearly assess the risks associated with this hidden exposure. A clear indication on food packaging and better information on the toxicity of hexane could encourage the industry to switch towards one of the numerous other alternative extraction methods already developed.

This paper reports the results of supercritical carbon dioxide (scCO2) extraction of β-carotene from Dunaliella salina as potential alternative to conventional organic solvent extraction. In pilot-scale scCO2 experiments, the pressure, temperature, and co-solvent concentration were varied. The supercritical extraction at 500 bar, 70 °C, and 10 wt% ethanol as co-solvent yielded in the highly efficient pigment recovery of over 90%. Techno-economic assessment demonstrated higher energy consumption for the scCO2 extraction that was compensated by lower solvent costs. Thus, comparable pigment production costs to the reference extraction with n-hexane were estimated for the scCO2 process. Due to the green solvent properties of scCO2 and ethanol, this approach is highly promising for extraction of algal biomass in industrial scale.

This study describes the operation of two independent parallel laboratory-scale biotrickling filters (BTFs) to degrade different types of binary volatile organic compound (VOC) mixtures. Comparison experiments were conducted to evaluate the effects of two typical VOCs, i.e., ethyl acetate (a hydrophilic VOC) and n -hexane (a hydrophobic VOC) on the removal performance of toluene (a moderately hydrophobic VOC) in BTFs ‘‘A” and ‘‘B”, respectively. Experiments were carried out by stabilizing the toluene concentration at 1.64 g m −3 and varying the concentrations of gas-phase ethyl acetate (0.85–2.8 g m −3 ) and n -hexane (0.85–2.8 g m −3 ) at an empty bed residence time (EBRT) of 30 s. In the presence of ethyl acetate (850 ± 55 mg m -3 ), toluene exhibited the highest removal efficiency (95.4 ± 2.2%) in BTF “A”. However, the removal rate of toluene varied from 48.1 ± 6.9% to 70.1 ± 6.8% when 850 ± 123 mg m -3 to 2800 ± 136 mg m -3 of n -hexane was introduced into BTF “B”. The high-throughput sequencing data revealed that the genera Pseudomonas and Comamonadaceae_unclassified are the core microorganisms responsible for the degradation of toluene. The intensity of the inhibitory or synergistic effects on toluene removal was influenced by the type and concentration of the introduced VOC, as well as the number and activity of the genera Pseudomonas and Comamonadaceae_unclassified . It provides insights into the interaction between binary VOCs during biofiltration from a microscopic perspective.

We investigated the possible anticancer mechanisms of Pteris vittata [PV] n-hexane extract on MCF-7 [breast cancer cell line]. Cultured cell lines were treated with various concentrations of this extract ± Baf-A1 [autophagic inhibitor]. Cells’ viability, apoptotic markers [caspase-7, Bax, and Bcl-2], autophagic markers [light chain 3 [LC-3] and P62/SQSTM1]], and the tumor suppressor P53 and its mRNA were checked by their corresponding methods. Treated cell lines showed significant concentration and time-dependent reductions in cell viability in response to PV-n-hexane extract and also exhibited a concomitant induction of apoptosis [increased chromatin condensation, nuclear fragmentation, and pro-apoptotic Bax, and cleaved caspase-7 levels while decreased Bcl-2 levels] and autophagy [increased autophagosomes vacuoles, and LC3B II levels while decreased P62/SQSTM1 levels]. Moreover, PV-n-hexane extract-treated cells showed significant increases in the P53 and its mRNA levels. The addition of Baf-A1 reversed the PV-n-hexane extract autophagic effects and increased apoptotic cell percentage with a much increase in the cleaved caspase-7 and P53 protein and its mRNA levels. We concluded that the PV-n-hexane extract exhibits cytotoxic effects on the MCF-7 cell line with significant reductions in cell viability and concomitant autophagy and apoptosis induction. Inhibition of autophagy in the PV-treated MCF-7 cells enhances apoptosis via a p35-dependent pathway.

There is a great interest in finding alternatives and green solvents in extraction processes to replace petroleum based solvents. In order to investigate these possibilities, computational methods, as Hansen solubility parameters (HSP) and conductor-like screening model for real solvent (COSMO-RS), were used in this work to predict the solvation power of a series of solvents in salmon fish lipids. Additionally, experimental studies were used to evaluate the performance in lipids extraction using 2-methyltetrahydrofurane, cyclopentyl methyl ether, dimethyl carbonate, isopropanol, ethanol, ethyl acetate, p-cymene and d-limonene compared with hexane. Lipid classes of extracts were obtained by using high performance thin-layer chromatography (HPTLC), whereas gas chromatography with a flame ionization detector (GC/FID) technique was employed to obtain fatty acid profiles. Some differences between theoretical and experimental results were observed, especially regarding the behavior of p-cymene and d-limonene, which separate from the predicted capability. Results obtained from HPTLC indicated that p-cymene and d-limonene extract triglycerides (TAGs) and diglycerides (DAGs) at levels of 73 and 19%, respectively, whereas the other studied extracts contain between 75 and 76% of TAGs and between 16 and 17% of DAGs. Fatty acid profiles, obtained by using GC-FID, indicated that saturated fatty acids (SFAs) between 19.5 and 19.9% of extracted oil, monounsaturated fatty acids (MUFAs) in the range between 43.5 and 44.9%, and PUFAs between 31.2 and 34.6% were extracted. p-Cymene and limonene extracts contained lower percentages than the other studied solvents of some PUFAs due probably to the fact that these unsaturated fatty acids are more susceptible to oxidative degradation than MUFAs. Ethyl acetate has been found to be the best alternative solvent to hexane for the extraction of salmon oil lipids. Graphical Abstract ᅟ

1,2-Unsaturated pyrrolizidine alkaloids (PA), their corresponding N-oxides (PANO), and tropane alkaloids (TA) are toxic secondary plant metabolites. Their possible transfer into the milk of dairy cows has been studied in feeding trials; however, only few data on the occurrence of these toxins in milk are available. In this study, the development of a sensitive analytical approach for the simultaneous detection and quantification of a broad range of 54 PA/PANO as well as of the TA atropine and scopolamine in milk of dairy cows is presented. The method optimisation focused on sensitivity and separation of PA/PANO isomers. Milk samples were extracted using liquid–liquid extraction with aqueous formic acid and n-hexane, followed by a cation-exchange solid-phase extraction for purification. Reversed phase liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis was performed using alkaline solvent conditions. Validation proved low limits of detection and quantification of 0.005 to 0.054 µg/L and of 0.009 to 0.123 µg/L, respectively. For 51 of the 54 tested PA/PANO and both TA, the recovery rates ranged from 64 to 127% with repeatability (RSDr) values below 15% at concentration levels of 0.05 and 0.50 µg/L and below 8% at a concentration level of 3.00 µg/L. Only three PANO did not match the validation criteria and were therefore regarded as semiquantitative. The final method was applied to 15 milk samples obtained from milk vending stations at farms and from local marketers in Bavaria, Germany. In three of the milk samples, traces of PA were detected.

Egg parasitoids, particularly Trichogrammatidae, play a crucial role in global biocontrol efforts. Their behavior is influenced by chemicals emitted by their hosts, such as kairomones. Among them, Trichogramma pretiosum (Riley) (Hym.; Trichogrammatidae) shows promise as a biocontrol agent on destructive Fall Armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lep.; Noctuidae). Given the invasiveness and widespread impact of FAW, early-stage prevention in the field is imperative. This study aimed to assess the potential of host insects viz.,Corcyra cephalonica (Stainton) (Lep.; Pyralidae) and S. frugiperda kairomones in optimizing the performance of T. pretiosum while parasitizing S. frugiperda. The top two hexane extracts from each host insect were also sent to JNU, AIRF in New Delhi for detailed GC-MS analysis. A four-armed olfactometer was developed to track the movements of T. pretiosum and validated with olfactory cues. Laboratory bioassays revealed that extracts from C. cephalonica and S. frugiperda eggs and moths effectively enhanced the performance of T. pretiosum. Optimal concentrations were determined through Petri dish bioassays, with C1 (10%) concentration of C. cephalonica eggs extract showing the highest Parasitoid Activity Index (PAI), percent parasitization, and adult emergence. Meanwhile, C2 (1%) concentration of S. frugiperda female extract exhibited the highest parasitization percentage and adult emergence. Further assessments in a polyhouse setting demonstrated that treated egg cards positioned 1 m from the release point achieved the highest mean percentage parasitization. Chemical composition analysis via GC-MS revealed that distinctive hydrocarbon and alcohol profiles in the extracts, suggesting their potential for manipulating parasitoid activity in biocontrol efforts. In the S. frugiperda female extract, 12 hydrocarbons and 3 alcohol groups were identified, with tetracontane as the predominant hydrocarbon compound followed by octane, heneicosane, and others. Meanwhile, the C. cephalonica egg extract displayed 9 hydrocarbons and 1 alcohol group, with dodecane leading in area percentage among the hydrocarbons followed by decane, nonane and others. The outputs of current study highlighted that T. pretiosum’s utilization of kairomones from C. cephalonica and S. frugiperda, enhancing its search behavior for host eggs. The identification and synthesis of these kairomonal compounds have the potential to revolutionize pest management, emphasizing the role of kairomones in empowering natural predators and parasitoids for sustainable agriculture.

Forensic entomology uses the age of insects, such as blow flies, to determine a minimum post-mortem interval (PMImin). Recent research has focused on using the analysis of specific cuticular hydrocarbons (CHCs) in adult insects and their empty puparia to estimate their age, as it has been shown that their profile changes are consistent with age. The current work is based on the weathering of five CHCs from empty puparia of Calliphora vicina that were stored in soil (field/outdoor) and non-soil (room/indoor conditions) based pupariation media for a total of six months. The experiment was conducted in a controlled environment chamber at a constant temperature of 25 ± 2 °C under constant darkness. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the cuticular hydrocarbons after they were extracted in n-Hexane. n-Pentacosane, n-Hexacosane, n-Heptacosane, n-Octacosane, and n-Nonacosane were the five CHCs investigated. Results showed that CHCs weathered more quickly in the soil than in the non-soil environment. It was also found that the abundance of Heptacosane increased in the samples during the fifth month when stored in a non-soil medium, while the abundances of all five CHCs were not detected after eight weeks onwards in soil pupation medium. [Display omitted] •Blow flies used to determine PMImin; research focuses on CHCs in insects and puparia.•The study investigated weathering of CHCs in Calliphora vicina puparia stored in soil and non-soil environments.•Gas chromatography-mass spectrometry was used to analyze the cuticular hydrocarbons after extraction in hexane.•CHCs weathered faster in soil; Heptacosane increased in non-soil medium after fifth month.•The relative abundance of all five CHCs were not detected after eight weeks onwards in soil pupation medium.