One-pot synthesis and antimicrobial evaluation of novel 3-cyanopyridine derivatives of (-)-β-pinene

The effects of alpha-pinene on the Nrf2-HO1 signaling pathway in gastric damage in rats

BACKGROUND

Alpha-pinene (α-pinene) is a monoterpene with gastroprotective activity. We evaluated the gastroprotective effect of α-pinene in the gastric damage model with ethanol.

METHODS

We evaluated the macroscopic evaluation of the stomach cavity, alteration in pH, mRNA expression of nuclear factor erythroid 2- related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), total antioxidant capacity (TAC) levels, and histopathological changes.

RESULTS

Pretreatment with α-pinene (10, 50 and 100 mg/kg i.p.) before oral administration of ethanol reduced gastric mucosal damage by increasing the percentage of ulcer inhibition. Alpha-pinene also increased gastric pH similar to omeprazole. In addition, the histopathological examination showed that in the groups pretreated with α-pinene 50 and 100 mg/kg, and omeprazole20 mg/kg, the lesions were less than the control group. Moreover, α- pinene 10, 50, 100, and omeprazole 20 mg/kg upregulated the NRF2 and HO1.

CONCLUSIONS

Our results show that pretreatment with α-pinene is effective in reducing ethanol-induced gastric damage through regulation of Nrf2/HO-1.

Cistus albidus L.-Review of a Traditional Mediterranean Medicinal Plant with Pharmacological Potential

Cistus albidus L. (Cistaceae) is a medicinal plant that has been used therapeutically since ancient times in the Mediterranean basin for its important pharmacological properties. The ability of C. albidus to produce large quantities of a wide range of natural metabolites makes it an attractive source of raw material. The main constituents with bioactive functions that exert pharmacological effects are terpenes and polyphenols, with more than 200 identified compounds. The purpose of this review is to offer a detailed account of the botanical, ethnological, phytochemical, and pharmacological characteristics of C. albidus with the aim of encouraging additional pharmaceutical investigations into the potential therapeutic benefits of this medicinal plant. This review was carried out using organized searches of the available literature up to July 2023. A detailed analysis of C. albidus confirms its traditional use as a medicinal plant. The outcome of several studies suggests a deeper involvement of certain polyphenols and terpenes in multiple mechanisms such as inflammation and pain, with a potential application focus on neurodegenerative diseases and disorders. Other diseases such as prostate cancer and leukemia have already been researched with promising results for this plant, for which no intoxication has been reported in humans.

Nitrogen-Containing Heterocyclic Compounds Obtained from Monoterpenes or Their Derivatives: Synthesis and Properties

Directed transformation of available natural compounds with native biological activity is a promising area of research in organic and medicinal chemistry aimed at finding effective drug substances. The number of scientific publications devoted to the transformation of natural compounds and investigations of their pharmacological properties, in particular, monoterpenes and their nearest derivatives, increases every year. At the same time, the chemistry of nitrogen-containing heterocyclic compounds has been actively developed since the 1950s after the news that the benzimidazole core is an integral part of the structure of vitamin B₁₂. At the time of writing this review, the data on chemical modifications of monoterpenes and their nearest derivatives leading to formation of compounds with a nitrogen-containing heterocycle core have not been summarized and systematized in terms of chemical transformations. In this review, we tried to summarize the literature data on the preparation and properties of nitrogen-containing heterocyclic compounds synthesized from monoterpenes/monoterpenoids and their nearest derivatives for the period from 2000 to 2021.

Novel O-acylated amidoximes and substituted 1,2,4-oxadiazoles synthesised from (+)-ketopinic acid possessing potent virus-inhibiting activity against phylogenetically distinct influenza A viruses

This article describes the synthesis and antiviral activity evaluation of new substituted 1,2,4-oxadiazoles containing a bicyclic substituent at position 5 of the heterocycle and O-acylated amidoximes as precursors for their synthesis. New compounds were obtained from the (+)-camphor derivative (+)-ketopinic acid. The chemical library was tested in vitro for cytotoxicity against the MDCK cell line and for antiviral activity against influenza viruses of H1N1 and H7N9 subtypes. The synthesised compounds exhibited high virus-inhibiting activity against the H1N1 influenza virus. Some synthesised compounds were also active against the influenza virus of a different antigenic subtype: H7N9. The mechanism of the virus-inhibiting activity of these compounds is based on their interference with the fusion activity of viral hemagglutinin (HA). No interference with the receptor-binding activity of HA has been demonstrated. According to molecular docking results, the selective antiviral activity of O-acylated amidoximes and 1,2,4-oxadiazoles is associated with their structural features. O-Acylated amidoximes are likely more complementary to the binding site located at the site of the fusion peptide, and 1,2,4-oxadiazoles are more complimentary to the site located at the site of proteolysis. Significant differences in the amino acid residues of the binding sites of HA's of different types allow us to explain the selective antiviral activity of the compounds under study.

β-Pinene Derived Products With Enhanced In Vitro Antimicrobial Activity

The development of new antimicrobials has always been a research hotspot. In this study, β-pinene-based derivatives were synthesized, and their antimicrobial activity was evaluated. The purpose was to develop some novel, promising new fungicides. Three β-pinene derivatives containing bis-hydronopyl were prepared, and their antifungal and antibacterial activities were evaluated against 6 plant pathogenic fungi and 4 bacterial species; a preliminary structure-activity relationship is discussed. The results indicated that the derivatives containing the blend of alkyl group and bis-hydronopyl had potent inhibitory activities against plant fungal pathogens and bacteria. Among these molecules, bis-hydronopyl dimethyl ammonium bromide showed excellent effects on Colletotrichum acutatum with a half-maximal effective concentration of 0.538 µg/mL, which was lower than that of carbendazim. Scanning electron microscope showed that after administration of bis-hydronopyl dimethyl ammonium bromide (compound 3a), the C. acutatum mycelia were sunken and deformed in comparison with the control group. Furthermore, the inhibitory activities of the methyl derivatives against the plant pathogens were better than those of the ethyl derivatives. These results provide new insights into the inhibition of fungi and bacteria by β-pinene derivatives, which may lead them to be used as precursor molecules for novel pesticides and antimicrobials in further research.

Monoterpenes and Their Derivatives-Recent Development in Biological and Medical Applications

Monoterpenes, comprising hydrocarbons, are the largest class of plant secondary metabolites and are commonly found in essential oils. Monoterpenes and their derivatives are key ingredients in the design and production of new biologically active compounds. This review focuses on selected aliphatic, monocyclic, and bicyclic monoterpenes like geraniol, thymol, myrtenal, pinene, camphor, borneol, and their modified structures. The compounds in question play a pivotal role in biological and medical applications. The review also discusses anti-inflammatory, antimicrobial, anticonvulsant, analgesic, antiviral, anticancer, antituberculosis, and antioxidant biological activities exhibited by monoterpenes and their derivatives. Particular attention is paid to the link between biological activity and the effect of structural modification of monoterpenes and monoterpenoids, as well as the introduction of various functionalized moieties into the molecules in question.

Antifungal Activity of β-Pinene-Based Hydronopyl Quaternary Ammonium Salts Against Phytopathogenic Fungi

β-Pinene can be used as a cheap source to synthesize a large number of high value-added derivatives. In this study, a series of β-pinene derivatives was prepared, and the antifungal activities of the compounds were assessed against phytopathogenic fungi. Eight N-alkyl hydronopyl diethyl ammonium halide salts were synthesized by the reaction of hydronopyl diethyl ammonium halide with 8 halogenated alkanes. The structures of the synthesized products were characterized by Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy and mass spectrometry. The antifungal activities of these derivatives were tested against 11 plant pathogens, and the preliminary structure-activity relationship is discussed. Some derivatives exhibited moderate to significant antifungal activity due to the fusion of the hydronopyl, a long-chain alkyl, bromine, and iodine anionic groups. In contrast to the structure-activity relationship of compounds 2a, 2b, and 2c, iodine ions in 2f, 2g, and 2f had a significant effect on enhancing the antifungal activity against Colletotrichum gloeosporioides, S clerotinia sclerotiorum, Phytophthora capsici, Phomopsis, Sphaeropsis sapinea, Glomerella cingulata, and Fusicoccum aesculi. A higher molecular weight could increase the antifungal activity against Fusarium proliferatum, Alternaria kikuchiana, Sclerotinia sclerotiorum, P. capsici, Phomopsis, and S. sapinea. Compounds 2d and 2e exhibited broad-spectrum antifungal activity against the tested strains. These derivatives are expected to be used as precursor molecules for novel pesticide development in further research.

Synthesis and Antimicrobial Evaluation of Some Novel Pyrimidine, Pyrazole, Chromene and Tetrahydrobenzo[b]thiophene Derivatives Bearing Pyrimidinthione Moiety

AIM AND OBJECTIVE

A novel collection of fused pyrimidine, pyridine, pyrazole, chromene and thiophene derivatives 2-30 have been newly synthesized by using the 1a, b as starting material. Fused pyrane exhibits a range of pharmacological activity such as cancer agents [1], antimicrobial [2-4], antioxidant [5], antiproliferative [6], cytotoxic activity [7], anticipated antitumor [8], antiparkinsonian [9] and anti-inflammatory [10]. Moreover, pyrane derivatives are well known for bacterial biofilm disruptor [11], anticonvulsant [12] and inhibitors of mycobacterium bovis [13].

MATERIALS AND METHODS

All melting points were measured using the Akofler Block instrument and are uncorrected. IR spectra (KBr) were recorded on a FTIR 5300 spectrometer (υ, cm-1). The 1H-NMR spectra were recorded on a Varian Gemini spectrometer. The 1H-NMR spectra were run at 300, 400 MHz and 13C-NMR spectra were run at 100 MHz in DMSO-d6, CDCl3 as solvents. The chemical shifts are expressed in parts per million (ppm) by using tetramethylsilane (TMS) as an internal reference, 1000 EX mass spectrometer at 70 eV. The purity of synthesized compounds was checked by thin-layer chromatography (TLC) (aluminum sheets) using nhexane, EtOAc (9:1, V/V, 7:3 V/V) eluent. Elemental analyses were carried out by the Microanalytical Research Center, Faculty of Science, and Microanalytical Unit, Faculty of Pharmacy, Cairo University, Egypt.

RESULTS AND DISCUSSION

A novel series of azoles and azines were designed and prepared via the reaction of 7-amino- 5-(4-chlorophenyl)-4-phenyl-2-thioxo-2,5-dihydro-1H-pyrano- [2,3-d]pyrimidine-6-carbonitrile 1a and 7-amino-4,5- diphenyl-2-thioxo-2,5-dihydro-1H-pyrano[2,3-d]-pyrimidine-6-carbonitrile 1b with some electrophilic and nucleophilic reagents. The structures of target compounds were confirmed by elemental analyses and spectral data. The novel synthesized compounds showed good antimicrobial activity against the previously mentioned microorganisms.

CONCLUSION

In conclusion, compounds 1a, 1b underwent ready cyclization to give fused heterocyclic compounds through reaction with different reagents and under different conditions and subjected to antimicrobial screening.

Jayaweera S, A. Dias D, Sharopov F, Taheri Y, Martins N, Baghalpour N, C. Cho W, Sharifi-Rad J. Therapeutic Potential of α- and β-Pinene: A Miracle Gift of Nature

α- and β-pinene are well-known representatives of the monoterpenes group, and are found in many plants' essential oils. A wide range of pharmacological activities have been reported, including antibiotic resistance modulation, anticoagulant, antitumor, antimicrobial, antimalarial, antioxidant, anti-inflammatory, anti-Leishmania, and analgesic effects. This article aims to summarize the most prominent effects of α- and β-pinene, namely their cytogenetic, gastroprotective, anxiolytic, cytoprotective, anticonvulsant, and neuroprotective effects, as well as their effects against H2O2-stimulated oxidative stress, pancreatitis, stress-stimulated hyperthermia, and pulpal pain. Finally, we will also discuss the bioavailability, administration, as well as their biological activity and clinical applications.

Derivatization of Natural Compound β-Pinene Enhances Its In Vitro Antifungal Activity against Plant Pathogens

Background: The development of new antifungal agents has always been a hot research topic in pesticide development. In this study, a series of derivatives of natural compound β-pinene were prepared, and the antifungal activities of these derivatives were evaluated. The purpose of this work is to develop some novel molecules as promising new fungicides. Methods: Through a variety of chemical reactions, β-pinene was transformed into a series of β-pinene-based derivatives containing amide moieties and acylthiourea moieties. The antifungal activities of these derivatives against five plant pathogens including Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana, Phomopsis sp. and Phytophthora capsici were tested; preliminary structure–activity relationship was discussed. Results: Some derivatives exhibited moderate or significant antifungal activity due to the fusion of the amide moiety or the acylthiourea moiety with the pinane skeleton. The structure–activity relationship analysis showed that the fluorine atom and the strong electron withdrawing nitro group, or trifluoromethyl group on the benzene ring of the derivatives had a significant effect on the improvement of the antifungal activity against Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana and Phomopsis sp. Meanwhile, the introduction of an ethyl group at the meta-position on the benzene ring of the derivatives could improve the antifungal activity against Phytophthora capsici. Compounds 4e, 4h, 4q, 4r exhibited broad-spectrum antifungal activity against the tested strains. Compound 4o had significant antifungal activity against Phytophthora capsici (IC₅₀ = 0.18 μmol/L). These derivatives were expected to be used as precursor molecules for novel pesticide development in further research.

Progress in the Chemistry of Tetrahydroquinolines

Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, being widespread in nature and present in a broad variety of pharmacologically active compounds. This Review summarizes the progress achieved in the chemistry of tetrahydroquinolines, with emphasis on their synthesis, during the period from mid-2010 to early 2018.

Design, synthesis and biological evaluation of novel β-pinene-based thiazole derivatives as potential anticancer agents via mitochondrial-mediated apoptosis pathway

A series of novel β-pinene-based thiazole derivatives were synthesized and characterized by HRMS, ¹H NMR, and ¹³C NMR analyses as potential antineoplastic agents. Derivatives were evaluated for their anticancer activities in vitro, and the data manifested that most target compounds showed potent anti-proliferative activities against three human cancer cell lines. Especially, compound 5g displayed excellent cytotoxic activity against Hela, CT-26, and SMMC-7721 cell lines with IC₅₀ values of 3.48 ± 0.14, 8.84 ± 0.16, and 6.69 ± 0.15 µM, respectively. To determine the underlying mechanism of compound 5g on cell viability, DAPI staining, Annexin-V/PI staining, JC-1 staining, DCFDA staining, and Western blot analysis were performed. Our data showed that compound 5g inhibited cell proliferation by inducing apoptosis and cell cycle arrest of Hela cells at the G0/G1 phase in a dose dependent manner. Further studies revealed that compound 5g enhanced levels of reactive oxygen species (ROS), caused a decrease in mitochondrial membrane potential, increased the release of mitochondrial cytochrome C, and affected the expression of Bax, Bcl-2, caspase-3 and caspase-9. Thus, our findings indicated that compound 5g induced apoptosis in Hela through ROS-mediated mitochondrial dysfunction signaling pathways.

Nopinone-based aggregation-induced emission (AIE)-active difluoroboron β-diketonate complex: photophysical, electrochemical and electroluminescence properties

Four difluoroboron (BF2) β-diketonate nopinone complexes 3a-3d that exhibited typical aggregation-induced emission (AIE) properties were synthesized using the natural renewable β-pinene derivative nopinone as the starting material. The thermal, photophysical, electrochemical and electroluminescent properties as well as the AIE properties of complexes 3a-3d were analyzed systematically. The data of photophysical and electrochemical demonstrated that compound 3b with a methoxy group exhibited the largest bathochromic shift, the highest absolute photoluminescence quantum yields and narrowest optical bandgap among 3a-3d. Using 3b as the emitter, electroluminescent (EL) device I exhibits blue-green light with CIE coordinates of (0.2774, 0.4531) and showed a better performance with a luminous efficacy (η p) of 7.09 lm W-1 and correlated color temperature (T C) of 7028 K. The results demonstrate that new AIE compounds are promising solid-state luminescent materials with practical utility in electroluminescent materials.

Extraction, characterization and bioactive properties of Nigella sativa seedcake

The extraction of phenolic compounds from Nigella sativa seed cake was optimized in terms of % of EtOH, extraction time, extraction temperature and solid to solvent ratio to maximize the phenolic content yield. The optimized conditions were 40% ethanol for 60 min, at 40 °C, 1/14 solid to sample ratio. The LC-MS profiling of the extract was found to contain many important phenolics such as Kaempferol, p-coumaroyl acid derivative, Thymol-O-sophoroside etc. The extract showed significant antioxidant activity with IC50 values 548.5 ± 9.4, 64.3 ± 2.7 μg/ml and 1.85 ± 0.2 mM TE/g in terms of DPPH scavenging activity, TEAC, and FRAP assay respectively. The results also indicated that the extract has a significant anti-inflammatory potential. This was evaluated as a measure of the membrane stabilization ability and protein denaturation inhibition capacity (IC50 values) and the activities were found to be 318.73 ± 6.98 and 150.39 ± 2.61 μg/ml respectively. Moreover, results of the study are promising and invite to further investigate the above activities in order to confirm them in different experimental situations and to consider for possible use in a nutraceutical approach.

Monoterpenes as a renewable source of biologically active compounds

Monoterpenes and their derivatives play an important role in the creation of new biologically active compounds including drugs. The review focuses on the data on various types of biological activity exhibited by monoterpenes and their derivatives, including analgesic, anti-inflammatory, anticonvulsant, antidepressant, anti-Alzheimer, anti-Parkinsonian, antiviral, and antibacterial (anti-tuberculosis) effects. Searching for novel potential drugs among monoterpene derivatives shows great promise for treating various pathologies. Special attention is paid to the effect of absolute configuration of monoterpenes and monoterpenoids on their activity.