Chemical composition and free radical-scavenging,anticancer and anti-inflammatory activities of the essential oil from Ocimum kilimandscharicum

ObjectiveThe essential oil from the leaves of Ocimum kilimandscharicum (EOOK), collected in Dourados-MS, was investigated for anticancer, anti-inflammatory and antioxidant activity and chemical composition.Materials and methodsThe essential oil was extracted by hydrodistillation, and the chemical composition was performed by gas chromatography–mass spectrometry. The essential oil was evaluated for free radical-scavenging activity using the DPPH assay and was tested in an anticancer assay against ten human cancer cell lines. The response parameter (GI₅₀) was calculated for the cell lines tested. The anti-inflammatory activity was evaluated using carrageenan-induced pleurisy in mice.ResultsThe chemical composition showed 45 components with a predominance of monoterpenes, such as camphor (51.81%), 1,8 cineole (20.13%) and limonene (11.23%). The EOOK exhibited potent free radical-scavenging activity by the DPPH assay with a GI₅₀ of 8.31 μg/ml. The major constituents, pure camphor (IC₅₀ = 12.56 μg/ml) and mixture of the limonene: 1, 8 cineole (IC₅₀ = 23.25 μg/ml) displayed a potent activity. The oral administration of EOOK (at 30 and 100 mg kg⁻¹), as well as the pure camphor or a mixture of 1,8 cineole with limonene, significantly inhibited the carrageenan (Cg) induced pleurisy, reducing the migration of total leukocytes in mice by 82 ± 4% (30 mg kg⁻¹ of EOOK), 95 ± 4% (100 mg kg⁻¹ of EOOK), 83 ± 9% (camphor) and 80 ± 5% (mixture of 1,8 cineole:limonene 1:1). In vitro cytotoxicity screening against a human ovarian cancer cell line displayed high selectivity and potent anticancer activity with GI₅₀ = 31.90 mg ml⁻¹. This work describes the anti-inflammatory, anticancer and antioxidant effects of EOOK for the first time.ConclusionsThe essential oil exhibited marked anti-inflammatory, antioxidant and anticancer effects, an effect that can be attributed the presence of majorital compounds, and the response profiles from chemical composition differed from other oils collected in different locales.     

Bioactivity of essential oil of Litsea cubeba from China and its main compounds against two stored product insects

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila, with LD₅₀ values of 27.33 μg/adult and 71.56 μg/cm², respectively, and also showed strong fumigant toxicity against the two stored product insects with LC₅₀ values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial) (27.49%), Z-citral (neral) (23.57%) and d-limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), d-limonene, β-pinene, α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral and linalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD₅₀ = 11.76, 12.74 μg/adult and 20.15, 99.97 μg/cm², respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54, 18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, d-limonene and linalool were strongly repellent against the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weaker repellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene and linalool, the other three compounds as well as the essential oil exhibited comparable repellency against the booklouse relative to DEET.     

Toxicity and repellency of origanum essential oil and its components against Tribolium castaneum (Coleoptera: Tenebrionidae) adults

The components of Origanum vulgare L. essential oil showing insecticidal activity and repellency against red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae), adults were analysed by GC-MS. All constituents were identified, and the main components were carvacrol (67.2%), p-cymene (16.2%), γ-terpinene (5.5%), thymol (4.9%), and linalool (2.1%). In a vapor phase fumigant assay, the origanum oil was more effective in closed conditions (LD₅₀ = 0.055 mg/cm³) than in open conditions (LD₅₀ > 0.353 mg/cm³). This suggests that toxicity is exerted largely in the vapor phase. Based on 24-h LD₅₀ values, the toxicity of caryophyllene oxide (0.00018 mg/cm³) was comparable with that of dichlorvos (0.00007 mg/cm³). In addition, thymol, camphene, α-pinene, p-cymene, and γ-terpinene showed good insecticidal activity (LD₅₀ = 0.012–0.195 mg/cm³). In repellency tests using 9 constituents of origanum oil, caryophyllene oxide showed complete repellency at 0.03 mg/cm². Hydrogenated monoterpenoids, such as thymol, α-pinene, carvacrol, and myrcene, elicited strong repellency at 0.03 and 0.006 mg/cm². Repellency depended on both time and concentration. These results indicate that origanum oil and its components could be potential candidates as a fumigant and repellent for managing T. castaneum adults.     

Pancreatic lipase inhibitory and antioxidative constituents from the aerial parts of Paeonia lactiflora Pall. (Ranunculaceae)

To date, there have been reports mostly about research results of the peony root in comparison to the aerial parts. According to our study, the aerial parts of P.lactiflora showed superior anti-oxidative and pancreatic lipase inhibitory activities than its root. Especially, the water extract and the ethyl acetate fraction of the ethanol extract exhibited potent pancreatic lipase inhibitory activity by 53.11 ± 1.22% and 46.16 ± 1.55% at the same dose of orlistat (62.5 ± 1.27%). The ethanol extract exhibited the best anti-oxidative activity with IC₅₀ of 17.08 ± 0.9 μg/mL, and the ethyl acetate fraction 19.75 ± 0.02 μg/mL, respectively, comparing to the positive control rutin (IC₅₀, 22.66 ± 0.29 μg/mL). From the anti-oxidative and pancreatic lipase inhibitory active fractions three new compounds, monplacphloroside (1), monplachydroxyquinoside (2) and herbacetin-7-O-β-d-sophoroside (3) were isolated along with 19 (4-22) known ones.Compounds, PGG (14), 1-O-methyl-2,3,4,6-tetra-O-galloyl-β-d-glucopyranose (17) and ethylgallate (9) were found to be the strongest antioxidants and pancreatic lipase inhibitors. Monoterpenes, albiflorin R₂ (19) and albiflorin (20) were determined for the first time as strong pancreatic lipase inhibitors. The presence of the esterified galloyl moiety, with its increasing numbers or the β-lactone cycle within the molecular structure plays an essential role for the enhancement of the pancreatic lipase enzyme inhibitory activity.     

Serotonin transporter protein (SERT) and P-glycoprotein (P-gp) binding activity of montanine and coccinine from three species of Haemanthus L. (Amaryllidaceae)

The alkaloid rich extracts from an acid/base extraction of bulb material of Haemanthus coccineus L., H. montanus Baker and H. sanguineus Jacq. revealed that two montanine type Amaryllidaceae alkaloids, montanine (1) and coccinine (2) were the major alkaloid constituents. Together these two alkaloids constituted 88, 91 and 98% of the total alkaloid extract from each species respectively. GC–MS analysis revealed that H. coccineus and H. sanguineus had a relative abundance of coccinine (74 and 91% respectively) to montanine (14 and 7% respectively); whereas H. montanus had 20% coccinine and 71% montanine. The three extracts and two isolated alkaloids were evaluated for binding to the serotonin transporter protein (SERT) in vitro. Affinity to SERT was highest in H. coccineus (IC₅₀ = 2.0 ± 1.1 μg/ml) followed by H. montanus (IC₅₀ = 6.8 ± 1.0 μg/ml) and H. sanguineus (IC₅₀ = 28.7 ± 1.1 μg/ml). Montanine (IC₅₀ = 121.3 ± 3.6 μM or 36.56 ± 1.14 μg/ml; K_i = 66.01 μM) was more active than coccinine (IC₅₀ = 196.3 ± 3.8 μM or 59.15 ± 1.08 μg/ml; K_i = 106.8 μM), both of which were less active than the total alkaloid extracts of each species investigated. The possible synergistic effects of two coccinine/montanine mixtures (80:20 and 20:80) were investigated, however the mixtures gave similar activities as the pure compounds and did not show any increase in activity or activity similar to the total alkaloid extracts. Thus the considerably higher activity observed in the total alkaloid extracts is not correlated to the relative proportions of coccinine and montanine in the extracts and thus are likely to be due to more potent unidentified minor constituents. Both alkaloids exhibited low binding affinity to P-glycoprotein (P-gp) as demonstrated by low inhibition of calcein-AM efflux in the MDCK-MDR1 cell line. This indicates that P-gp efflux will not be limiting for blood–brain-barrier passage of the alkaloids.     

Chemical composition,angiotensin I-converting enzyme (ACE) inhibitory,antioxidant and antimicrobial activities of the essential oil from south Tunisian Ajuga pseudoiva Rob. Lamiaceae

The essential oil of Ajuga pseudoiva, collected from Tunisia, was analyzed using gas chromatography–mass spectroscopy. Thirty-two compounds accounting for 95.76% of the total oil were identified. Sesquiterpenes were found to be the most abundant components of A. pseudoiva oil. And they were mainly represented by viridiflorol (30.17%), germacrene B (9.26%) (α, β and γ)-eudesmol (8.11%) and aromadendrene (7.45%). The essential oil of A. pseudoiva showed radical scavengers activity (IC₅₀ = 0.72 mg/mL) and displayed lipid peroxidation inhibitory activity (IC₅₀ = 0.6 mg/mL). A. pseudoiva essential oil was also found to exhibit a dose-dependent ACE inhibitory activity with an IC₅₀ value of 65.5 μg/mL. Moreover, the antimicrobial activity of the essential oil was tested against 17 species of microorganisms, and the results obtained showed significant antibacterial activity against the Gram-positive and Gram-negative bacteria, with inhibition zones and minimal inhibitory concentration values of 14–32 mm and 84–137 μg/mL and 6–21 mm and 105–336 μg/mL, respectively. Higher activity was also found against several fungal strains.     

Synthesis and investigation of dihydroxychalcones as calpain and cathepsin inhibitors

In order to identify potential calpain and cathepsin inhibitors we prepared 12 dihydroxychalcone analogues and tested their ability to inhibit μ-calpain, m-calpain, cathepsins B and L. In the calpain inhibition test, compound 10 exhibited the most active inhibitory activity against m-calpain with an IC₅₀ value of 25.25 ± 0.901 μM. With respect to inhibition of cathepsins B and L, compound 13 exhibited the most potent inhibitory activity on cathepsin L and moderate inhibitory activity on cathepsin B with IC₅₀ values of 2.80 ± 0.100 and 11.47 ± 0.087 μM, respectively. Our results suggest the possibility of developing dual calpain and cathepsin inhibitors by properly modulating structures and/or combining the essential aspects of the functional group effective for specific calpain and cathepsin inhibition.     

Phytosynthesis of silver nanoparticles from Jatropha integerrima Jacq. flower extract and their possible applications as antibacterial and antioxidant agent

Jatropha integerrima Jacq. flower extract was used for the synthesis of silver nanoparticles in the current study. Various spectroscopic analyses were used to characterize the synthesized nanoparticles (JIF-AgNPs). The antibacterial efficacy of JIF-AgNPs was studied by well diffusion and microdilution techniques. In addition, the impact of JIF-AgNPs on free radicals was evaluated. On the ultraviolet–visible spectrum, the nanoparticles exhibit the highest absorbance at 422 nm. Based on the Fourier transform infrared spectrum, phenols and amino acids were involved in capping the JIF-AgNPs. Crystalline sphere-shaped nanoparticles with an average size of 50.07 nm and zeta potential of ?19.0 mV were confirmed by X-ray diffraction, transmission electron microscopy, and dynamic light scattering analysis respectively. The JIF-AgNPs exhibit the highest and lowest growth inhibitory activity towards E. coli and B. subtilis. The minimal inhibitory concentration of JIF-AgNPs against E. coli, K. pneumoniae, S. aureus, and B. subtilis were 2.5, 5.0, 5.0, and 7.5 μg/mL, respectively. The JIF-AgNPs exhibited significant radical scavenging activities against DPPH (IC₅₀-32.5 ± 0.06 µg/mL), hydroxyl (IC₅₀-25 ± 0.09 µg/mL), Superoxide (IC₅₀-42.5 ± 0.13 µg/mL), and ABTs (IC₅₀-33.5 ± 0.15 µg/mL). Thus, synthesized nanoparticles were a good alternative to develop an antibacterial and antioxidant agent.     

Alkaloids from the roots of Stemona javanica (Kunth) Engl. (Stemonaceae) and their anti-malarial,acetylcholinesterase inhibitory and cytotoxic activities

Two new protostemonine-type alkaloids, javastemonine A and B (3 and 4) have been isolated from the root extracts of Stemona javanica together with four known Stemona alkaloids, 13-demethoxy-11(S*),12(R*)-dihydroprotostemonine (1), isoprotostemonine (2), protostemonine and isomaistemonine. The structures and relative configurations of the new alkaloids were determined by spectroscopic analysis. The alkaloids 1 and 2 and protostemonine showed moderated antiplasmodial activities against the Plasmodium falciparum strains, TM4 (IC₅₀ values of 17.7 ± 3.7, 16.8 ± 5.4, 16.0 ± 4.2 μg/mL, respectively) and K1 (IC₅₀ values of 16.8 ± 3.1, 14.1 ± 3.7, 11.9 ± 3.3 μg/mL, respectively). These compounds showed no significant cytotoxicities against KB or Vero cells or acetylcholinesterase inhibitory activities.     

Novel biphenyl bis-sulfonamides as acetyl and butyrylcholinesterase inhibitors: Synthesis,biological evaluation and molecular modeling studies

A series of new biphenyl bis-sulfonamide derivatives 2a–3p were synthesized in good to excellent yield (76–98%). The inhibitory potential of the synthesized compounds on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was investigated. Most of the screened compounds showed modest in vitro inhibition for both AChE and BChE. Compared to the reference compound eserine (IC₅₀ 0.04 ± 0.0001 μM for AChE) and (IC₅₀ 0.85 ± 0.0001 μM for BChE), the IC₅₀ values of these compounds were ranged from 2.27 ± 0.01 to 123.11 ± 0.04 μM for AChE and 7.74 ± 0.07 to <400 μM for BuChE. Among the tested compounds, 3p was found to be the most potent against AChE (IC₅₀ 2.27 ± 0.01 μM), whereas 3g exhibited the highest inhibition for BChE (IC₅₀ 7.74 ± 0.07 μM). Structure–activity relationship (SAR) of these compounds was developed and elaborated with the help of molecular docking studies.     

Oleanolic acid (OA) as an antileishmanial agent: Biological evaluation and in silico mechanistic insights

Although a worldwide health problem, leishmaniasis is considered a highly neglected disease, lacking efficient and low toxic treatment. The efforts for new drug development are based on alternatives such as new uses for well-known drugs, in silico and synthetic studies and naturally derived compounds. Oleanolic acid (OA) is a pentacyclic triterpenoid widely distributed throughout the Plantae kingdom that displays several pharmacological activities. OA showed potent leishmancidal effects in different Leishmania species, both against promastigotes (IC_{50 L. braziliensis} 30.47 ± 6.35 μM; IC_{50 L. amazonensis} 40.46 ± 14.21 μM; IC_{50 L. infantum} 65.93 ± 15.12 μM) and amastigotes (IC_{50 L. braziliensis} 68.75 ± 16.55 μM; IC_{50 L. amazonensis} 38.45 ± 12.05 μM; IC_{50 L. infantum} 64.08 ± 23.52 μM), with low cytotoxicity against mouse peritoneal macrophages (CC₅₀ 235.80 ± 36.95 μM). Moreover, in silico studies performed to evaluate OA molecular properties and to elucidate the possible mechanism of action over the Leishmania enzyme sterol 14α-demethylase (CYP51) suggested that OA interacts efficiently with CYP51 and could inhibit the ergosterol synthesis pathway. Collectively, these data indicate that OA is a good candidate as leading compound for the development of a new leishmaniasis treatment.     

Synthesis of alpha amylase inhibitors based on privileged indole scaffold

Twenty five derivatives of indole carbohydrazide (1–25) had been synthesized. These compounds were characterized using ¹H NMR and EI-MS, and further evaluated for their α-amylase inhibitory potential. The analogs (1–25) showed varying degree of α-amylase inhibitory potential.ranging between 9.28 and 599.0 µM when compared with standard acarbose having IC₅₀ value 8.78 ± 0.16 µM. Six analogs, 25 (IC₅₀ = 9.28 ± 0.153 µM), 22 (IC₅₀ = 9.79 ± 0.43 µM), 4 (IC₅₀ = 11.08 ± 0.357 µM), 1 (IC₅₀ = 12.65 ± 0.169 µM), 8 (IC₅₀ = 21.37 ± 0.07 µM) and 14 (IC₅₀ = 43.21 ± 0.14 µM) showed potent α-amylase inhibition as compared to the standard acarbose (IC₅₀ = 8.78 ± 0.16 µM). All other analogs displayed good to moderate inhibitory potential. Structure-activity relationship was established through the interaction of the active compounds with enzyme active site with the help of docking studies.     

Glycolipid ester-type heterodimers from Ipomoea tyrianthina and their pharmacological activity

Tyrianthins A (1) and B (2), two new partially acylated glycolipid ester-type heterodimers were isolated from Ipomoea tyrianthina. Scammonic acid A was determined as the glycosidic acid in both monomeric units. Tyrianthin A (1) (IC₅₀ 0.24 ± 0.09 μM and E_max 81.80 ± 0.98%), and tyrianthin B (2) (IC₅₀ 0.14 ± 0.08 μM and E_max 87.68 ± 0.72%) showed significant in vitro relaxant effect on aortic rat rings, in endothelium- and concentration-dependent manners. Also, these compounds were able to increase the release of GABA and glutamic acid in brain cortex, and displayed weak antimycobacterial activity.     

Identification of novel acetylcholinesterase inhibitors: Indolopyrazoline derivatives and molecular docking studies

The synthesis of novel indolopyrazoline derivatives (P1-P4 and Q1-Q4) has been characterized and evaluated as potential anti-Alzheimer agents through in vitro Acetylcholinesterase (AChE) inhibition and radical scavenging activity (antioxidant) studies. Specifically, Q3 shows AChE inhibition (IC₅₀: 0.68 ± 0.13 μM) with strong DPPH and ABTS radical scavenging activity (IC₅₀: 13.77 ± 0.25 μM and IC₅₀: 12.59 ± 0.21 μM), respectively. While P3 exhibited as the second most potent compound with AChE inhibition (IC₅₀: 0.74 ± 0.09 μM) and with DPPH and ABTS radical scavenging activity (IC₅₀: 13.52 ± 0.62 μM and IC₅₀: 13.13 ± 0.85 μM), respectively. Finally, molecular docking studies provided prospective evidence to identify key interactions between the active inhibitors and the AChE that furthermore led us to the identification of plausible binding mode of novel indolopyrazoline derivatives. Additionally, in-silico ADME prediction using QikProp shows that these derivatives fulfilled all the properties of CNS acting drugs. This study confirms the first time reporting of indolopyrazoline derivatives as potential anti-Alzheimer agents.     

Synthesis,in vitro α-glucosidase inhibitory activity and molecular docking studies of new thiazole derivatives

Current study based on the synthesis of new thiazole derivatives via “one pot” multicomponent reaction, evaluation of their in vitro α-glucosidase inhibitory activities, and in silico studies. All synthetic compounds were fully characterized by ¹H NMR, ¹³C NMR and EIMS. CHN analysis was also performed. These newly synthesized compounds showed activities in the range of IC₅₀ = 9.06 ± 0.10–82.50 ± 1.70 μM as compared to standard acarbose (IC₅₀ = 38.25 ± 0.12 μM). It is worth mentioning that most of the compounds such as 1 (IC₅₀ = 23.60 ± 0.39 μM), 2 (IC₅₀ = 22.70 ± 0.60 μM), 3 (IC₅₀ = 22.40 ± 0.32 μM), 4 (IC₅₀ = 26.5 ± 0.40 μM), 6 (IC₅₀ = 34.60 ± 0.60 μM), 7 (IC₅₀ = 26.20 ± 0.43 μM), 8 (IC₅₀ = 14.06 ± 0.18 μM), 9 (IC₅₀ = 17.60 ± 0.28 μM), 10 (IC₅₀ = 27.16 ± 0.41 μM), 11 (IC₅₀ = 19.16 ± 0.19 μM), 12 (IC₅₀ = 9.06 ± 0.10 μM), 13 (IC₅₀ = 12.80 ± 0.21 μM), 14 (IC₅₀ = 11.94 ± 0.18 μM), 15 (IC₅₀ = 16.90 ± 0.20 μM), 16 (IC₅₀ = 12.60 ± 0.14 μM), 17 (IC₅₀ = 16.30 ± 0.29 μM), and 18 (IC₅₀ = 32.60 ± 0.61 μM) exhibited potent inhibitory potential. Molecular docking study was performed in order to understand the molecular interactions between the molecule and enzyme. Newly identified α-glucosidase inhibitors except few were found to be completely non-toxic.     

Terpenoids with cytotoxic activity from the branches and leaves of Pyrus pashia

Twenty terpenoids, including a new triterpenoid (1) and a new monoterpenoid (20), were isolated from the branches and leaves of Pyrus pashia. The structures of two new compounds were determined to be 2α, 3β, 27-trihydroxyolean-12-en-28-oic acid (1) and (4α)-3-(5,5-dimethyltetrahydrofuranyl)-1-buten-3-ol 3-O-β-d-glucopyranoside (20) on the basis of spectroscopic analysis (IR, HRESIMS, 1D and 2D NMR) and chemical method. Some of the isolated compounds were evaluated for their cytotoxic activity against a panel of human cancer cell lines by MTT assay, using cisplatin as a positive control. Compound 14 exhibited cytotoxic activities against A549 (IC₅₀ = 19.18 ± 4.26 μM), Hela (IC₅₀ = 12.56 ± 3.89 μM), SGC7901 (IC₅₀ = 10.48 ± 1.95 μM) and NHI-1975 (IC₅₀ = 7.38 ± 2.31 μM) cell lines as well as compound 12 displayed cytotoxic activities against A549 (IC₅₀ = 14.71 ± 1.47 μM) and Hela (IC₅₀ = 12.22 ± 1.88 μM) cell lines.     

Synthesis of 6-chloro-2-Aryl-1H-imidazo[4,5-b]pyridine derivatives: Antidiabetic,antioxidant, β-glucuronidase inhibiton and their molecular docking studies

6-Chloro-2-Aryl-1H-imidazo[4,5-b]pyridine derivatives 1–26 were synthesized and characterized by various spectroscopic techniques. All these derivatives were evaluated for their antiglycation, antioxidant and β-glucuronidase potential followed their docking studies. In antiglycation assay, compound 2 (IC₅₀ = 240.10 ± 2.50 μM) and 4 (IC₅₀ = 240.30 ± 2.90 μM) was found to be most active compound of this series, while compounds 3 (IC₅₀ = 260.10 ± 2.50 μM), 6 (IC₅₀ = 290.60 ± 3.60 μM), 13 (IC₅₀ = 288.20 ± 3.00 μM) and 26 (IC₅₀ = 292.10 ± 3.20 μM) also showed better activities than the standard rutin (IC₅₀ = 294.50 ± 1.50 μM). In antioxidant assay, compound 1 (IC₅₀ = 69.45 ± 0.25 μM), 2 (IC₅₀ = 58.10 ± 2.50 μM), 3 (IC₅₀ = 74.25 ± 1.10 μM), and 4 (IC₅₀ = 72.50 ± 3.30 μM) showed good activities. In β-glucuronidase activity, compounds 3 (IC₅₀ = 29.25 ± 0.50 μM), compound 1 (IC₅₀ = 30.10 ± 0.60 μM) and compound 4 (IC₅₀ = 46.10 ± 1.10 μM) showed a significant activity as compared to than standard D-Saccharic acid 1,4-lactonec (IC₅₀ = 48.50 ± 1.25 μM) and their interaction with the enzyme was confirm by docking studies.     

Evaluation of insecticidal activity of the essential oil of Allium chinense G. Don and its major constituents against Liposcelis bostrychophila Badonnel

Water-distilled essential oil from the dried bulbs of Allium chinense (Liliaceae) was analyzed by gas chromatography–mass spectrometry (GC–MS). Eighteen compounds, accounting for 98.4% of the total oil, were identified and the main components of the essential oil of A. chinense were methyl allyl trisulfide (30.7%), dimethyl trisulfide (24.1%), methyl propyl disulfide (12.8%) and dimethyl disulfide (9.6%) followed by methyl allyl disulfide (3.4%) and methyl propyl trisulfide (3.6%). The essential oil exhibited contact toxicity against the booklice (Liposcelis bostrychophila) with an LC₅₀ value of 441.8 μg/cm² while the two major constituents, dimethyl trisulfide and methyl propyl disulfide had LC₅₀ values of 153.0 μg/cm² and 738.0 μg/cm² against the booklice, respectively. The essential oil of A. chinense possessed strong fumigant toxicity against the booklice with an LC₅₀ value of 186.5 μg/l while methyl allyl trisulfide (LC₅₀ = 90.4 μg/l) and dimethyl trisulfide (LC₅₀ = 114.2 μg/l) exhibited stronger fumigant toxicity than methyl propyl disulfide (LC₅₀ = 243.4 μg/l) and dimethyl disulfide (LC₅₀ = 340.8 μg/l) against the booklice. The results indicated that the essential oil and its major constituents have potential for development into natural insecticides or fumigants for control of insects in stored grains.     

Carbohydrazones as new class of carbonic anhydrase inhibitors: Synthesis,kinetics, and ligand docking studies

Discovery and development of carbonic anhydrase inhibitors is crucial for their clinical use as antiepileptic, diurectic and antiglaucoma agents. Keeping this in mind, we have synthesized carbohydrazones 1–27 and evaluated them for their in vitro carbonic anhydrase inhibitory potential. Out of twenty-seven compounds, compounds 1 (IC₅₀ = 1.33 ± 0.01 µM), 2 (IC₅₀ = 1.85 ± 0.24 µM), 3 (IC₅₀ = 1.37 ± 0.06 µM), and 9 (IC₅₀ = 1.46 ± 0.12 µM) have showed carbonic anhydrase inhibition better than the standard drug zonisamide (IC₅₀ = 1.86 ± 0.03 µM). Moreover, compounds 4 (IC₅₀ = 2.32 ± 0.04 µM), 5 (IC₅₀ = 3.96 ± 0.35 µM), 7 (IC₅₀ = 2.33 ± 0.02 µM), and 8 (IC₅₀ = 2.67 ± 0.01 µM) showed good inhibitory activity. Cheminformatic analysis has shown that compounds 1 and 2 possess lead-like properties. In addition, kinetic and molecular docking studies were also performed to investigate the binding interaction between carbohydrazones and carbonic anhydrase enzyme. This study has identified a novel and potent class of carbonic anhydrase inhibitors with the potential to be investigated further.     

Toxicity of basil and orange essential oils and their components against two coleopteran stored products insect pests

Two commercialized essential oils and their constituent compounds were investigated for fumigant and contact activities against two grain storage insects, adults of the maize weevil (Sitophilus zeamais) and the red flour beetle (Tribolium castaneum). The two commercialized basil and orange oils showed strong fumigant and contact activities against S. zeamais and T. castaneum. The constituents of the basil oil were linalool (21.83%), estragole (74.29%), and α-humulene (2.17%), and those of the orange oil were α-pinene (0.54%), sabinene (0.38%), β-myrcene (1.98%), limonene (96.5%), and linalool (0.6%). As a toxic fumigant, the basil oil was more effective (24-h LC₅₀ = 0.014 and 0.020 mg cm^− 3) than the orange oil (24-h LC₅₀ = 0.106 and 0.130 mg cm^− 3) against S. zeamais and T. castaneum adults, respectively. Among the constituents of the two essential oils, the toxicity of estragole was the highest (0.004 and 0.013), followed by linalool (0.016 and 0.023), limonene (0.122 and 0.171), α-pinene (0.264 and 0.273), and β-myrcene (0.274 and 0.275) based on 24-h LC₅₀ values (mg cm^− 3). Similar results were obtained in a contact toxicity test. The contact activity of basil oil was more toxic than orange oil, and estragole and linalool showed pronounced contact toxicity against S. zeamais and T. castaneum adults. Alpha-humulene had no activity as a fumigant at the tested doses, but it did have an effect as a contact poison, having 24-h LD₅₀ values of 0.040 and 0.045 mg adult^− 1 to S. zeamais and T. castaneum, respectively. Although basil oil, orange oil, and their components displayed both contact and fumigant toxicities, their effects were mainly exerted by fumigant action via the vapor phase. Thus, basil oil, orange oil, and their components could be potential candidates as new fumigants for the control of S. zeamais and T. castaneum adults.