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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.

Aiming for the heart C-reactive protein (CRP) is a clinical marker for inflammatory disease and infection, but it also binds to damaged cells and activates complement, a host defence and pro-inflammatory system of serum proteins. Complement-mediated inflammation exacerbates tissue injury in heart attacks, and human CRP increases damage in a rat model of acute myocardial infarction via a complement-dependent mechanism. These observations point to CRP as a possible target for drugs intended to protect the heart. Pepys et al . therefore designed a specific small-molecule CRP inhibitor. Five molecules of this palindromic compound are bound by two pentameric CRP molecules arranged face-to-face, as in the X-ray crystal structure of the complex on the cover. The inhibitor blocks the adverse effects of human CRP in rats with acute myocardial infarction, suggesting that early therapeutic inhibition of CRP might be beneficial for heart attack patients. A new drug inhibits the adverse effects of C-reactive protein, a blood protein that has been shown to exacerbate damage in the heart and brain after blockage of the blood supply. Complement-mediated inflammation exacerbates the tissue injury of ischaemic necrosis in heart attacks and strokes, the most common causes of death in developed countries. Large infarct size increases immediate morbidity and mortality and, in survivors of the acute event, larger non-functional scars adversely affect long-term prognosis. There is thus an important unmet medical need for new cardioprotective and neuroprotective treatments. We have previously shown that human C-reactive protein (CRP), the classical acute-phase protein that binds to ligands exposed in damaged tissue and then activates complement 1 , increases myocardial and cerebral infarct size in rats subjected to coronary or cerebral artery ligation, respectively 2 , 3 . Rat CRP does not activate rat complement, whereas human CRP activates both rat and human complement 4 . Administration of human CRP to rats is thus an excellent model for the actions of endogenous human CRP 2 , 3 . Here we report the design, synthesis and efficacy of 1,6-bis(phosphocholine)-hexane as a specific small-molecule inhibitor of CRP. Five molecules of this palindromic compound are bound by two pentameric CRP molecules, crosslinking and occluding the ligand-binding B-face of CRP and blocking its functions. Administration of 1,6-bis(phosphocholine)-hexane to rats undergoing acute myocardial infarction abrogated the increase in infarct size and cardiac dysfunction produced by injection of human CRP. Therapeutic inhibition of CRP is thus a promising new approach to cardioprotection in acute myocardial infarction, and may also provide neuroprotection in stroke. Potential wider applications include other inflammatory, infective and tissue-damaging conditions characterized by increased CRP production, in which binding of CRP to exposed ligands in damaged cells may lead to complement-mediated exacerbation of tissue injury.

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.

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.

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

Lemon grass, formally identified as Cymbopogon citratus , is a plant that belongs to the Poaceae family. The present work aimed to examine the chemical composition by GC/MS analysis and assess the biological potential of C. citratus volatile oil and n -hexane extract. The volatile oil and n -hexane extract were evaluated for antioxidant potential and tested for their enzyme inhibition against tyrosinase, butyrylcholinesterase (BChE), acetylcholinesterase (AChE), α -amylase, and α -glucosidase. The chemical analysis of the lemongrass n-hexane extract (HE) and volatile oil (VO) revealed that the main constituents in the HE are aliphatic hydrocarbons (42.98%), triterpenoids (20.14%), and aromatic hydrocarbons (17.25%). Conversely, the main constituents of the (VO) are predominantly monoterpenes, namely α-citral (36.08%), β -citral (34.22%), and β -myrcene (13.84%). The oil showed more potent antioxidant potential in DPPH, ABTS, CUPRAC, FRAP, and phosphomolybdenum (10.18, 35.69 mg Trolox equivalent/g, 98.97 and 69.73 mg Trolox equivalent/g and 43.01 mmol Trolox equivalent/g). The HE displayed higher BChE (1.53 mg Galanthamine equivalent)/g), as well as α -amylase and α -glucosidase inhibitory activities (0.39 and 2.40 mmol Acarbose equivalent/g). The VO demonstrated more potent tyrosinase inhibitory activities (57.19 mg Kojic acid equivalent/g) along with acetyl and butyrylcholinesterase inhibition. Dominant compounds exhibited the ability to bind with high affinity to various target proteins, with a particular affinity for AChE and BChE. The volatile oil and n -hexane extract of C. citratus show significant promise as a viable choice for the advancement of novel therapeutic strategies aimed at addressing oxidative stress, neurodegeneration, and diabetes.

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.

Presynthesized perovskite quantum dots are very promising for making films with different compositions, as they decouple crystallization and film-formation processes. However, fabricating large-area uniform films using perovskite quantum dots is still very challenging due to the complex fluidic dynamics of the solvents. Here, we report a robust film-formation approach using an environmental-friendly binary-solvent strategy. Nonbenzene solvents, n-octane and n-hexane, are mixed to manipulate the fluidic and evaporation dynamics of the perovskite quantum dot inks, resulting in balanced Marangoni flow, enhanced ink spreadability, and uniform solute-redistribution. We can therefore blade-coat large-area uniform perovskite films with different compositions using the same fabrication parameters. White and red perovskite light-emitting diodes incorporating blade-coated films exhibit a decent external quantum efficiency of 10.6% and 15.3% (0.04 cm 2 ), and show a uniform emission up to 28 cm 2 . This work represents a significant step toward the application of perovskite light-emitting diodes in flat panel solid-state lighting. Achieving large-area uniform film is the primary challenge to commercialise perovskite LEDs. The authors here employ green binary solvents to regulate the fluidic dynamics in perovskite quantum dot inks during blade-coating to achieve efficient 28 cm2-sized red and white perovskite LEDs.