Identification of algicidal monoterpenoids from four chemotypes of Cinnamomum camphora and their algicidal mechanisms on Microcystis aeruginosa.

Cyanobacterial blooms cause serious environmental issues, and plant secondary metabolites are considered as new algaecide for controlling them. Cinnamomum camphora produces a wide spectrum of terpenoids and has 4 main chemotypes, including linalool, camphor, eucalyptol and borneol chemotype. To develop the new cyanobacterial algaecide by using suitable chemotype of Cinnamomum camphora and the main terpenoids, we analyzed the terpenoid composition in the 4 chemotype extracts, evaluated the algicidal effects of the extracts and their typical monoterpenoids on Microcystis aeruginosa, and investigated the algicidal mechanism of the stronger algicidal agents. Among the 4 chemotypes, eucalyptol and borneol chemotype extracts exhibited stronger algicidal effects. In the 4 chemotype extracts, monoterpenoids were the main compounds, of which linalool, camphor, eucalyptol and borneol were the typical components. Among the 4 typical monoterpenoids, eucalyptol and borneol showed stronger algicidal effects, which killed 78.8% and 100% M. aeruginosa cells, respectively, at 1.2 mM after 48 h. In 1.2 mM eucalyptol and borneol treatments, the reactive oxygen species levels markedly increased, and the caspase-3-like activity also raised. With prolonging the treatment time, M. aeruginosa cells gradually shrank and wrinkled, and the cell TUNEL fluorescence intensity and DNA degradation gradually enhanced, indicating that the lethal mechanism is causing apoptosis-like programmed cell death (PCD). Therefore, eucalyptol and borneol chemotype extracts and their typical monoterpenoids have the potential for developing as algaecides to control cyanobacteria through triggering apoptosis-like PCD.

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression.

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

Modulation of transient receptor potential (TRP) channels by plant derived substances used in over-the-counter cough and cold remedies.

BACKGROUND: Upper respiratory tract infections (URTIs) impact all age groups and have a significant economic and social burden on society, worldwide. Most URTIs are mild and self-limiting, but due to the wide range of possible causative agents, including Rhinovirus (hRV), Adenovirus, Respiratory Syncytial Virus (RSV), Coronavirus and Influenza, there is no single and effective treatment. Over-the-counter (OTC) remedies, including traditional medicines and those containing plant derived substances, help to alleviate symptoms including inflammation, pain, fever and cough. PURPOSE: This systematic review focuses on the role of the major plant derived substances in several OTC remedies used to treat cold symptoms, with a particular focus on the transient receptor potential (TRP) channels involved in pain and cough. METHODS: Literature searches were done using Pubmed and Web of Science, with no date limitations, using the principles of the PRISMA statement. The search terms used were 'TRP channel AND plant compound', 'cough AND plant compound', 'cough AND TRP channels AND plant compound', 'cough AND P2X3 AND plant compound' and 'P2X3 AND plant compound' where plant compound represents menthol or camphor or eucalyptus or turpentine or thymol. RESULTS: The literature reviewed showed that menthol activates TRPM8 and may inhibit respiratory reflexes reducing irritation and cough. Menthol has a bimodal action on TRPA1, but inhibition may have an analgesic effect. Eucalyptus also activates TRPM8 and inhibits TRPA1 whilst down regulating P2X3, aiding in the reduction of cough, pain and airway irritation. Camphor inhibits TRPA1 and the activation of TRPM8 may add to the effects of menthol. Activation of TRPV1 by camphor, may also have an analgesic effect. CONCLUSIONS: The literature suggests that these plant derived substances have multifaceted actions and can interact with the TRP 'cough' receptors. The plant derived substances used in cough and cold medicines have the potential to target multiple symptoms experienced during a cold.

Effects of Calendula officinalis and Capsicum annum glycolic extracts on planktonic cells and biofilms of multidrug-resistant strains of Klebsiella pneumoniae and Pseudomonas aeruginosa.

Empirical knowledge of natural plant extracts is increasingly proving to be a promising field. The effect of Calendula officinalis L. (CO) and Capsicum annum (CA) glycolic extracts (GlExt) have potential that should be further developed in microbial tests. The effect of CO-GlExt and CA-GlExt was evaluated on eight multidrug-resistant clinical strains of Klebsiella pneumoniae and Pseudomonas aeruginosa, as well as collection strains for each bacterial. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined in comparison with 0.12% chlorhexidine. The tests were performed on single species biofilms, at 5 min and 24 h, using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. The MIC and MBC of the extract ranged from 1.56 to 50 mg mL-1 for all strains evaluated. Analysis of the MTT assay revealed a strong antimicrobial potential of CA-GlExt, comparable to chlorhexidine. The findings suggest that CA-GlExt is effective against multidrug-resistant strains of K. pneumoniae and P. aeruginosa in planktonic state and biofilms.

Contribution of Constituents in Rosemary-Magnolia Compound Essential Oil to Antibacterial, Antioxidant and Cytotoxicity Bioactivities Revealed by Grey Correlation Analysis.

The compound of essential oils (EOs) is a key approach to achieving the superimposed efficacy of plant EOs. In this article, grey correlation analysis was applied for the first time to explore the compound ratios and contribution between constituents and the bioactivity of the compound EOs. There were 12 active constituents shared in rosemary and magnolia EOs prepared by negative pressure distillation. With different proportions, these two EOs were blended and analyzed for the antioxidant, bacteriostatic and antitumor effects. According to the results of the inhibition circle, minimum bactericidal and inhibitory concentration, the most obvious inhibition effect of the compound EOs on different strains of bacteria was shown in Staphylococcus aureus. The results of antioxidant test showed that single EO from rosemary had the best antioxidant effect, and its EO content was directly proportional to the antioxidant effect. The cytotoxicity results showed that, there was a significant difference in the lethality of the compound EOs between tumor cells Mcf-7 (human breast cancer cells) and SGC-7901 cells (human gastric cancer cells). Furthermore, single EO from magnolia had an obvious inhibitory effect on the growth of Mcf-7 cells and SGC-7901 cells, and the cell lethality rate was as high as 95.19 % and 97.96 %, respectively. As the results of grey correlation analysis, the constituents with the maximal correlation of inhibitory effects on bacteria were as follows: S. aureus - Terpinolene (0.893), E. coli - Eucalyptol (0.901), B. subtilis - α-Pinene (0.823), B. cereus - Terpinolene (0.913) and Salmonella - α-Phellandrene (0.855). For the ABTS and DPPH scavenging effects, the constituents with the maximal correlation were (-)-Camphor (0.860) and ß-Pinene (0.780), respectively. In terms of the effects of the active constituents of compound EOs on the inhibitory activities of tumor cells Mcf-7 and SGC-7901, the three active constituents of γ-Terpinene, (R)-(+)-ß-Citronellol and (-)-Camphor were in the top three, and their correlation were Mcf-7 (0.833, 0.820, 0.795) and SGC-7901 (0.797, 0.766, 0.740). Our study determined the contribution degree of active constituents in the antibacterial, antioxidant, and antitumor bioactivities of rosemary-magnolia compound EOs, and also provided new insights for the research of EOs combination formulations.

Comparative study on eucalyptol and camphor rich essential oils from rhizomes of Hedychium spicatum Sm. and their pharmacological, antioxidant and antifungal activities.

The aim of present study was to evaluate chemical composition and different biological activities viz., pharmacological and antioxidant activities of essential oils. The chemical composition of essential oils was determined by gas chromatography/mass spectrometry while biological activities were evaluated by standard protocols. Essential oils of Hedychium spicatum Sm. from two different ecological niches viz; Nainital (Site-I) and Himachal Pradesh (Site-II) of India revealed the qualitative and quantitative chemo-diversity. Both the oils were dominated by oxygenated terpenoids. Major marker compounds identified were eucalyptol, camphor, linalool, α-eudesmol, 10-epi-γ-eudesmol, and iso-borneol. Both the oils exhibited anti-inflammatory activity suppressing 17.60 % to 33.57 % inflammation at 100mg/kg b. wt. dose levels compared to ibuprofen-treated group (40.06 %). The sub-acute inflammation in oils-treated mice groups (50 and 100 mg/kg b. wt.) increased on day 2 but showed a gradual decrease from day 3 onwards and then recovered to normal by day 10. The antinociception percentage for doses (50 and 100 mg/kg b. wt.) ranged from 33.70-40.46 % in Site-I and 30.34-42.39 % in Site-II compared to standard drug, ibuprofen (43.08 %). The oils also showed a good antipyretic effect by suppressing Brewer's yeast (Saccharomyces cerevisiae) induced pyrexia after oil dose injection. The oils also exhibited good antioxidant activity.

Synthesis and Anti-Fungal/Oomycete Activity of Novel Sulfonamide Derivatives Containing Camphor Scaffold.

Twelve novel camphor sulfonamide derivatives 2a-2l were synthesized and characterized by 1 H-NMR, 13 C-NMR and HRMS spectra. The anti-fungal/oomycete activity bioassay showed that some of the title compounds displayed moderate to good anti-fungal/oomycete activities against B. dothidea and P. capsici. Compound 2d exhibited the best in vitro antifungal activity toward B. dothidea. The in vivo experiment revealed that compound 2d possessed considerable anti-B. dothidea effect at 200 mg/L. Mechanism study showed that compound 2d could increase the cell membrane permeability. In addition, the in vitro enzyme inhibition assay and molecular docking results indicated that compound 2d could be a potential SDH inhibitor.

Enhanced Toxicity of Bisphenols Together with UV Filters in Water: Identification of Synergy and Antagonism in Three-Component Mixtures.

Contaminants of emerging concern (CEC) localize in the biome in variable combinations of complex mixtures that are often environmentally persistent, bioaccumulate and biomagnify, prompting a need for extensive monitoring. Many cosmetics include UV filters that are listed as CECs, such as benzophenone derivatives (oxybenzone, OXYB), cinnamates (2-ethylhexyl 4-methoxycinnamate, EMC) and camphor derivatives (4-methylbenzylidene-camphor, 4MBC). Furthermore, in numerous water sources, these UV filters have been detected together with Bisphenols (BPs), which are commonly used in plastics and can be physiologically detrimental. We utilized bioluminescent bacteria (Microtox assay) to monitor these CEC mixtures at environmentally relevant doses, and performed the first systematic study involving three sunscreen components (OXYB, 4MBC and EMC) and three BPs (BPA, BPS or BPF). Moreover, a breast cell line and cell viability assay were employed to determine the possible effect of these mixtures on human cells. Toxicity modeling, with concentration addition (CA) and independent action (IA) approaches, was performed, followed by data interpretation using Model Deviation Ratio (MDR) evaluation. The results show that UV filter sunscreen constituents and BPs interact at environmentally relevant concentrations. Of notable interest, mixtures containing any pair of three BPs (e.g., BPA + BPS, BPA + BPF and BPS + BPF), together with one sunscreen component (OXYB, 4MBC or EMC), showed strong synergy or overadditive effects. On the other hand, mixtures containing two UV filters (any pair of OXYB, 4MBC and EMC) and one BP (BPA, BPS or BPF) had a strong propensity towards concentration dependent underestimation. The three-component mixtures of UV filters (4MBC, EMC and OXYB) acted in an antagonistic manner toward each other, which was confirmed using a human cell line model. This study is one of the most comprehensive involving sunscreen constituents and BPs in complex mixtures, and provides new insights into potentially important interactions between these compounds.

Synthesis and Antiviral Properties of Camphor-Derived Iminothiazolidine-4-Ones and 2,3-Dihydrothiazoles.

A set of heterocyclic products was synthesized from natural (+)-camphor and semi-synthetic (-)-camphor. Then, 2-Imino-4-thiazolidinones and 2,3-dihydrothiazoles were obtained using a three-step procedure. For the synthesized compounds, their antiviral activity against the vaccinia virus and Marburg virus was studied. New promising agents active against both viruses were found among the tested compounds.

Chemical composition and synergistic effect of three Moroccan lavender EOs with ciprofloxacin against foodborne bacteria: a promising approach to modulate antimicrobial resistance.

The aim of this study was to determine the chemical profile of the essential oils (EOs) of three Moroccan lavender species (Lavandula pedunculata, LP; Lavandula angustifolia, LA; and Lavandula maroccana, LM) and to investigate, for the first time, the synergistic effect of the optimal mixture of the EOs with conventional antibiotic ciprofloxacin against three pathogenic foodborne bacteria. Gas chromatography/mass spectrometry analysis showed that eucalyptol (39·05%), camphor (24·21%) and borneol (8·29%) were the dominant compounds of LA-EO. LP-EO was characterized by the abundance of camphor (74·51%) and fenchone (27·06%), whereas carvacrol (42·08%), camphor (17·95%) and fenchone (12·05%) were the main constituents of LM-EO. EOs alone or combined showed a remarkable antimicrobial activity against the tested bacteria with minimum inhibitory concentrations (MICs) ranging from 3·53 to 15·96 mg ml-1 . The optimal mixture, calculated using a mixture design, corresponded to 19% LA, 38% LP and 43% LM. All combination of the EOs and the best EO mixture with ciprofloxacin exhibited a total synergism with fractional inhibitory concentration index values ranging from 0·27 to 0·37. The best EO mixture showed the highest gain of 128-fold, especially against Salmonella spp., more than that found testing the EOs separately. These findings should be taken into consideration for a possible application in the pharmaceutical and food industries.

Neuroprotective role of camphor against ciprofloxacin induced depression in rats: modulation of Nrf-2 and TLR4.

BACKGROUND: Depression affects people feeling to be anxious, worried, and restless. They also lose interest in activities, concentrating and appetite, they finally may attempt suicide. Depression is the second chronic disease, as a source of the global burden of disease, after heart disease. Its prevalence elevated seven times during the COVID-19. AIM: The current study was designed to evaluate camphor neuroprotective role against rats' ciprofloxacin-induced depression. MATERIALS AND METHODS: Depression was induced by administration of ciprofloxacin (50 mg/kg; orally) for 21 days. Wister albino male rats were divided into five groups. Group I (normal control): rats were given normal saline. Group II: rats received camphor (10 mg/kg; i.p.) for 21 days. Group III (depression control): rats received ciprofloxacin only. Groups IV and V: rats received camphor (5 and 10 mg/kg; i.p.) for 21 days concurrent with ciprofloxacin. Behavior tests as forced swimming test, activity cage, and rotarod were estimated. Oxidative stress and antioxidant biomarkers as malondialdehyde (MDA), nitric oxide (NO), catalase, and nuclear factor erythroid 2-related factor 2 (Nrf-2) besides inflammatory biomarkers as Toll-like receptor 4 (TLR4) and tumor necrosis factor alpha (TNF-α) as well as neurotransmitters were determined. Finally, histopathological examination was done. RESULTS: Camphor increased catalase and Nrf-2 activities, decreased NO, MDA, TNF-α, TLR4 serum levels, and elevating brain contents of serotonin, dopamine, gamma-amino butyric acid (GABA) and P190-RHO GTP protein with normal neuronal cells of the frontal cortex. CONCLUSION: Camphor has neuroprotective effect via modulation of Nrf-2 and TLR4 against ciprofloxacin-induced depression in rats.

(+)-Camphor and (-)-borneol derivatives as potential anti-orthopoxvirus agents.

Although the World Health Organisation had announced that smallpox was eradicated over 40 years ago, the disease and other related pathogenic poxviruses such as monkeypox remain potential bioterrorist weapons and could also re-emerge as natural infections. We have previously reported (+)-camphor and (-)-borneol derivatives with an antiviral activity against the vaccinia virus. This virus is similar to the variola virus (VARV), the causative agent of smallpox, but can be studied at BSL-2 facilities. In the present study, we evaluated the antiviral activity of the most potent compounds against VARV, cowpox virus, and ectromelia virus (ECTV). Among the compounds tested, 4-bromo-N'-((1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)benzohydrazide 18 is the most effective compound against various orthopoxviruses, including VARV, with an EC50 value of 13.9 µM and a selectivity index of 206. Also, (+)-camphor thiosemicarbazone 9 was found to be active against VARV and ECTV.

Camphor and Eucalyptol-Anticandidal Spectrum, Antivirulence Effect, Efflux Pumps Interference and Cytotoxicity.

Candidaalbicans represents one of the most common fungal pathogens. Due to its increasing incidence and the poor efficacy of available antifungals, finding novel antifungal molecules is of great importance. Camphor and eucalyptol are bioactive terpenoid plant constituents and their antifungal properties have been explored previously. In this study, we examined their ability to inhibit the growth of different Candida species in suspension and biofilm, to block hyphal transition along with their impact on genes encoding for efflux pumps (CDR1 and CDR2), ergosterol biosynthesis (ERG11), and cytotoxicity to primary liver cells. Camphor showed excellent antifungal activity with a minimal inhibitory concentration of 0.125-0.35 mg/mL while eucalyptol was active in the range of 2-23 mg/mL. The results showed camphor's potential to reduce fungal virulence traits, that is, biofilm establishment and hyphae formation. On the other hand, camphor and eucalyptol treatments upregulated CDR1;CDR2 was positively regulated after eucalyptol application while camphor downregulated it. Neither had an impact on ERG11 expression. The beneficial antifungal activities of camphor were achieved with an amount that was non-toxic to porcine liver cells, making it a promising antifungal compound for future development. The antifungal concentration of eucalyptol caused cytotoxic effects and increased expression of efflux pump genes, which suggests that it is an unsuitable antifungal candidate.

Antinociceptive activity of 3ß-6ß-16ß-trihydroxylup-20 (29)-ene triterpene isolated from Combretum leprosum leaves in adult zebrafish (Danio rerio).

Drugs used to treat pain are associated with adverse effects, increasing the search for new drugs as an alternative treatment for pain. Therefore, we evaluated the antinociceptive behavior and possible neuromodulation mechanisms of triterpene 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene (CLF-1) isolated from Combretum leprosum leaves in zebrafish. Zebrafish (n = 6/group) were pretreated with CLF-1 (0.1 or 0.3 or 1.0 mg/mL; i.p.) and underwent nociception behavior tests. The antinociceptive effect of CFL-1 was tested for modulation by opioid (naloxone), nitrergic (L-NAME), nitric oxide and guanylate cyclase synthesis inhibitor (methylene blue), NMDA (Ketamine), TRPV1 (ruthenium red), TRPA1 (camphor), or ASIC (amiloride) antagonists. The corneal antinociceptive effect of CFL-1 was tested for modulation by TRPV1 (capsazepine). The effect of CFL-1 on zebrafish locomotor behavior was evaluated with the open field test. The acute toxicity study was conducted. CLF-1 reduced nociceptive behavior and corneal in zebrafish without mortalities and without altering the animals' locomotion. Thus, CFL-1 presenting pharmacological potential for the treatment of acute pain and corneal pain, and this effect is modulated by the opioids, nitrergic system, NMDA receptors and TRP and ASIC channels.

Reconsidering Hydrosols as Main Products of Aromatic Plants Manufactory: The Lavandin (Lavandula intermedia) Case Study in Tuscany.

: The present work evaluates for the first time two Lavandin (Lavandula × intermedia Emeric ex Loisel.) aromatic waters obtained from different plant organs, the flowers and the stems. Both extracts were analysed by GC-MS, which indicates semi-quantitative differences between the major metabolites including linalool, 1,8-cineole, camphor, linalyl acetate and 4-terpineol. 1H-NMR and LC-MS investigation confirmed the presence of these compounds. Moreover, behavioural tests with the food insect pest Tribolium confusum (Coleoptera Tenebrionidae) showed a good repellency for both hydrosols extracts with RD50 values of 3.6 and 3.3 µL cm-2 for the flowers and stems, respectively; at the higher concentrations, however, the hydrosol extract from the flowers is expected to be more effective than the one from the stems. The effect of the flowers and stems aromatic water of Lavandin on seed germination of Raphanus sativus was also evaluated. Results showed that seed germination was completely inhibited by flowers hydrolate, having a possible application as natural herbicide. The overall experience with these Lavandin extracts indicates the potential of improved hydrolates to become the main distillation products, rather than by-products, of the aromatic plants manufacturing; this stimulates further discussions about the potential positive impacts that such a shift could have in the context of ecopharmacognosy.

Synthesis of Camphor-Derived Bis(pyrazolylpyridine) Rhodium(III) Complexes: Structure-Reactivity Relationships and Biological Activity.

Two novel rhodium(III) complexes, namely, [RhIII(X)Cl3] (X = 2 2,6-bis((4 S,7 R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-1 H-4,7-methanoindazol-3-yl)pyridine or 2,6-bis((4 S,7 R)-1,7,8,8-tetramethyl-4,5,6,7-tetrahydro-1 H-4,7-methanoindazol-3-yl)pyridine), were synthesized from camphor derivatives of a bis(pyrazolylpyridine), tridentate nitrogen-donor chelate system, giving [RhIII(H2L*)Cl3] (1a) and [RhIII(Me2L*)Cl3] (1b). A rhodium(III) terpyridine (terpy) ligand complex, [RhIII(terpy)Cl3] (1c), was also synthesized. By single-crystal X-ray analysis, 1b crystallizes in an orthorhombic P212121 system, with two molecules in the asymmetric unit. Tridentate coordination by the N,N,N-donor localizes the central nitrogen atom close to the rhodium(III) center. Compounds 1a and 1b were reactive toward l-methionine (l-Met), guanosine-5'-monophosphate (5'-GMP), and glutathione (GSH), with an order of reactivity of 5'-GMP > GSH > l-Met. The order of reactivity of the RhIII complexes was: 1b> 1a > 1c. The RhIII complexes showed affinity for calf thymus DNA and bovine serum albumin by UV-vis and emission spectral studies. Furthermore, 1b showed significant in vitro cytotoxicity against human epithelial colorectal carcinoma cells. Since the RhIII complexes have similar coordination modes, stability differences were evaluated by density functional theory (DFT) calculations (B3LYP(CPCM)/LANL2DZp). With (H2L*) and (terpy) as model ligands, DFT calculations suggest that both tridentate ligand systems have similar stability. In addition, molecular docking suggests that all test compounds have affinity for the minor groove of DNA, while 1b and 1c have potential for DNA intercalation.

Synthesis of Camphecene and Cytisine Conjugates Using Click Chemistry Methodology and Study of Their Antiviral Activity.

A series of camphecene and quinolizidine alkaloid (-)-cytisine conjugates has been obtained for the first time using 'click' chemistry methodology. The cytotoxicity and virus-inhibiting activity of compounds were determined against MDCK cells and influenza virus A/Puerto Rico/8/34 (H1N1), correspondingly, in in vitro tests. Based on the results obtained, values of 50 % cytotoxic dose (CC50 ), 50 % inhibition dose (IC50 ) and selectivity index (SI) were determined for each compound. It has been shown that the antiviral activity is affected by the length and nature of linkers between cytisine and camphor units. Conjugate 13 ((1R,5S)-3-(6-{4-[(2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]amino}ethoxy)methyl]-1H-1,2,3-triazol-1-yl}hexyl)-1,2,3,4,5,6-hexahydro-8H-1,5-methanopyrido[1,2-a][1,5]diazocin-8-one), which contains cytisine fragment separated from triazole ring by -C6 H12 - aliphatic linker, showed the highest activity at relatively low toxicity (CC50 =168 µmol, IC50 =8 µmol, SI=20). Its selectivity index appeared higher than that of reference compound, rimantadine. According to theoretical calculations, the antiviral activity of the lead compound 13 can be explained by its influence on the functioning of neuraminidase.

Chemical Characterization of Euphorbia heterophylla L. Essential Oils and Their Antioxidant Activity and Allelopathic Potential on Cenchrus echinatus L.

The genus Euphorbia attracted the attention of many researchers worldwide from natural products, bioactivity, and ecological perspective. The essential oils (EOs) of Euphorbia heterophylla are poorly studied. Therefore, the present study aimed to provide a detailed profile of the E. heterophylla EOs as well as to determine their antioxidant and allelopathic activities. The EOs from aerial parts of E. heterophylla were extracted using hydrodistillation and analyzed via GC/MS. The antioxidant activity was determined based on scavenging of the free radical, 1,1-diphenyl-2-picrylhydrazyl and H2 O2 . Various concentrations of the EOs were tested against the noxious weed, Cenchrus echinatus. Thirty-five compounds were identified representing 100 % of the total mass. Four classes of components were characterized, among which terpenoids were the main components (88.70 %). Monoterpenes represented the main class (69.48 %), followed by sesquiterpenes (18.63 %), and only one diterpenoid, kaur-16-ene, was identified. 1,8-Cineole (32.03 %), camphor (16.54 %), ß-elemene (5.92 %), endo-borneol (4.94 %), limonene (4.27 %), pentatriacontane (3.91 %), and α-pinene (3.89 %) were the major compounds. The EOs composition of Egyptian E. heterophylla ecospecies was comparable to that of other reported Euphorbia species, although it showed no correlation with Nigerian E. heterophylla ecospecies. The EOs from E. heterophylla aerial parts exhibited significant antioxidant activity. Moreover, a concentration of 100 µL L-1 of the EOs reduced the germination, root, and shoot growth of C. echinatus by about 93.95 %, 84.6 %, and 57.8 %, respectively. Therefore, the EOs from E. heterophylla could be integrated into the control of this weed, as eco-friendly biocontrol method. Further study is needed to characterize their allelopathic activity under field conditions as well as to evaluate their durability and biosafety.

Synthesis of camphecene derivatives using click chemistry methodology and study of their antiviral activity.

A series of seventeen tetrazole derivatives of 1,7,7-trimethyl-[2.2.1]bicycloheptane were synthesized using click chemistry methodology and characterized by spectral data. Studies of cytotoxicity and in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells of the compounds obtained were performed. The structure-activity relationship analysis suggests that to possess virus-inhibiting activity, the compounds of this group should bear oxygen atom with a short linker (C2-C4), either as a hydroxyl group (18, 19, 29), keto-group (21) or as a part of a heterocycle (24). These compounds demonstrated low cytotoxicity along with high anti-viral activity.

Comparative Morphology, Transcription, and Proteomics Study Revealing the Key Molecular Mechanism of Camphor on the Potato Tuber Sprouting Effect.

Sprouting regulation in potato tubers is important for improving commercial value and producing new plants. Camphor shows flexible inhibition of tuber sprouting and prolongs the storage period of potato, but its underlying mechanism remains unknown. The results of the present study suggest that camphor inhibition caused bud growth deformities and necrosis, but after moving to more ventilated conditions, new sprouts grew from the bud eye of the tuber. Subsequently, the sucrose and fructose contents as well as polyphenol oxidase (PPO) activity were assessed after camphor inhibition. Transcription and proteomics data from dormancy (D), sprouting (S), camphor inhibition (C), and recovery sprouting (R) samples showed changes in the expression levels of approximately 4000 transcripts, and 700 proteins showed different abundances. KEGG (Kyoto encyclopaedia of genes and genomes) pathway analysis of the transcription levels indicated that phytohormone synthesis and signal transduction play important roles in tuber sprouting. Camphor inhibited these processes, particularly for gibberellic acid, brassinosteroids, and ethylene, leading to dysregulation of physiological processes such as cutin, suberine and wax biosynthesis, fatty acid elongation, phenylpropanoid biosynthesis, and starch and sucrose metabolism, resulting in bud necrosis and prolonged storage periods. The KEGG pathway correlation between transcripts and proteins revealed that terpenoid backbone biosynthesis and plant-pathogen interaction pathways showed significant differences in D vs. S samples, but 13 pathways were remarkably different in the D vs. C groups, as camphor inhibition significantly increased both the transcription levels and protein abundance of pathogenesis-related protein PR-10a (or STH-2), the pathogenesis-related P2-like precursor protein, and the kirola-like protein as compared to sprouting. In recovery sprouting, these genes and proteins were decreased at both the transcriptional level and in protein abundance. It was important to find that the inhibitory effect of camphor on potato tuber sprout was reversible, revealing the action mechanism was similar to resistance to pathogen infection. The present study provides a theoretical basis for the application of camphor in prolonging seed potato storage.