Biogenic fabrication of ZnO@EC and MgO@EC using Eucalyptus leaf extract for the removal of hexavalent chromium Cr(VI) ions from water.

Zinc and magnesium oxide nanoparticles were fabricated using green synthesis method for the sequestration of hexavalent chromium Cr(VI) from the aqueous medium. The biogenically prepared ZnO@EC and MgO@EC nanoparticles were successfully loaded on the Eucalyptus. The prepared nanomaterials were characterized using various techniques such as FESEM, TGA, XRD, EDX, FTIR, BET, and elemental mapping. FE-SEM analysis has revealed the surface morphology of ZnO nanoparticles, which were rod-like and spherical in shape, whereas MgO nanoparticles were of irregular shape. Batch mode was selected to remove the hexavalent chromium from aqueous solution using the prepared nanomaterials. The Cr(VI) adsorption was carried out under optimized conditions, viz., pH (3.0), adsorbent dose (0.05 g), contact time (150 min), temperature (25 ± 2 °C), and initial concentration (50 mg/L). The experimental results were compared using the different isotherm models; The observations have indicated that experimental data fit better with Freundlich (R2 = 0.99) and Langmuir (R2 = 0.99) isotherms, respectively. The maximum adsorption capacity of ZnO@EC and MgO@EC for Cr(VI) was found to be 49.3 and 17.4 mg/g, respectively. The regeneration study of the adsorbents was conducted using different desorbing agents viz., ethanol, NaOH, and NaCl. The desorbing agent NaOH performed better and showed removal percentage of 34.24% and 20.18% for ZnO@EC and MgO@EC, respectively, after the three reusability cycles. The kinetics of reaction was assessed using the pseudo-first-order and pseudo-second-order kinetic models. The experimental data of both the nanomaterials ZnO@EC and MgO@EC obeyed pseudo-second-order model with correlation coefficient values 0.999 and 0.983, respectively. The thermodynamic study confirmed that adsorption was feasible, spontaneous, and endothermic. The adsorbents were tested for spiked real water which confirms their applicability and potential in real water systems also. The results indicated fair removal of chromium suggesting applicability of both adsorbents.

Chemical composition and antimicrobial activity of the leaf essential oil of Ravenia spectabilis Engl. (Rutaceae).

Ravenia spectabilis Engl. belongs to the family Rutaceae is known to possess several biologically active phytomolecules. This study was planned to investigate the chemical composition and antimicrobial activity of the leaf essential oil of R. spectabilis. The hydrodistillation of fresh leaves of R. spectabilis gave 0.19 ± 0.02% essential oil. The resulting essential oil was analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Altogether, thirty-one constituents forming 97.6 ± 1.72% of the total oil composition were identified. Major components of the oil were sabinene (60.8 ± 0.36%), α-pinene (5.4 ± 0.30%), myrcene (4.8 ± 0.25%), δ-3-carene (4.7 ± 0.62%) and ß-pinene (4.3 ± 0.17%). The in-vitro antimicrobial potential of the oil was examined against eight human pathogenic bacterial and fungal strains. The essential oil showed significant activity against Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, Candida albicans, and Candida kefyr. This is the first report on R. spectabilis leaf essential oil composition and its antimicrobial activity. The essential oil could be a promising natural source of sabinene and antimicrobial for developing new phytotherapeutics.

Chemical composition and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of cassumunar-ginger.

BACKGROUND: Zingiber montanum (J.Koenig) Link ex A.Dietr. (Zingiberaceae), commonly known as cassumunar-ginger, is a folk remedy for the treatment of inflammations, sprains, rheumatism and asthma. The aim of the present study was to assess the chemical composition, and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of the essential oil of Z. montanum originating from India. RESULTS: The hydrodistilled essential oil of Z. montanum rhizome was analyzed using gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. A total of 49 constituents, forming 98.7-99.9% of the total oil compositions, was identified. The essential oil was characterized by higher amount of monoterpene hydrocarbons (32.6-43.5%), phenylbutanoids (27.5-41.2%) and oxygenated monoterpenes (11.4-34.1%). Major constituents of the oil were sabinene (13.5-38.0%), (E)-1-(3',4'-dimethoxyphenyl)buta-1,3-diene (DMPBD) (20.6-35.3%), terpinen-4-ol (9.0-31.3%), γ-terpinene (1.1-4.8%) and ß-phellandrene (1.0-4.4%). The oil was evaluated against eight pathogenic bacteria and two fungal strains. It exhibited low to good antibacterial activity (minimum inhibitory concentration: 125-500 µg mL-1 ) and moderate antifungal activity (250 µg mL-1 ) against the tested strains. The oil reduced germination (69.8%) and inhibited the root and shoot growth of lettuce significantly (LD50 : 3.58 µL plate-1 ). However, it did not demonstrate acetylcholinesterase inhibitory activity up to a concentration of 10 mg mL-1 . CONCLUSIONS: The essential oil of Z. montanum can be used as a potential source of DMPBD, terpinen-4-ol and sabinene for pharmaceutical products. The results of the present study add significant information to the pharmacological activity of Z. montanum native to India. © 2017 Society of Chemical Industry.

Chemical Composition and Allelopathic, Antibacterial, Antifungal, and Antiacetylcholinesterase Activity of Fish-mint (Houttuynia cordataThunb.) from India.

Fish-mint (Houttuynia cordataThunb.), belonging to family Saururaceae, has long been used as food and traditional herbal medicine. The present study was framed to assess the changes occurring in the essential-oil composition of H. cordata during annual growth and to evaluate allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities. The essential-oil content ranged from 0.06 - 0.14% and 0.08 - 0.16% in aerial parts and underground stem, respectively. The essential oils were analysed by GC-FID, GC/MS, and NMR (1 H and 13 C). Major constituents of aerial-parts oil was 2-undecanone (19.4 - 56.3%), myrcene (2.6 - 44.3%), ethyl decanoate (0.0 - 10.6%), ethyl dodecanoate (1.1 - 8.6%), 2-tridecanone (0.5 - 8.3%), and decanal (1.1 - 6.9%). However, major constituents of underground-stem oil were 2-undecanone (29.5 - 42.3%), myrcene (14.4 - 20.8%), sabinene (6.0 - 11.1%), 2-tridecanone (1.8 - 10.5%), ß-pinene (5.3 - 10.0%), and ethyl dodecanoate (0.8 - 7.3%). Cluster analysis revealed that essential-oil composition varied substantially due to the plant parts and season of collection. The oils exhibited significant allelopathic (inhibition: 77.8 - 88.8%; LD50 : 2.45 - 3.05 µl/plate), antibacterial (MIC: 0.52 - 2.08 µl/ml; MBC: bacteriostatic) and antifungal (MIC: 2.08 - 33.33 µl/ml; MFC: 4.16 - 33.33 µl/ml) activities. The results indicate that the essential oil from H. cordata has a significant potential to allow future exploration and exploitation as a natural antimicrobial and allelopathic agent.

Compositional and Enantiomeric Analysis of the Essential Oil of Taxodium distichum from India.

The leaf essential oil composition of Taxodium distichum L., collected from the foothills of Uttarakhand, India was analyzed using gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) equipped with DB-5 (5% diphenyl-95% dimethyl polysiloxane) and ß-cyclodextrin (6-tertiarybutyldimethylsiliyl-2,3-diethyl-ß-cyclodextrin) capillary columns. Seventeen constituents, representing 90.3 to 99.4% of composition were identified in the essential oils from different seasons, viz. spring, summer, rainy, autumn and winter. The essential oil composition was mainly dominated by monoterpene hydrocarbons, represented mainly by α-pinene (81.9-94.3%). Other constituents of the oil were myrcene (0.5-4.7%), ß-pinene (2.2-2.9%), limonene (0.5-1.5%), camphene (≤ 0.03-1.5%), and α-terpineol (upto 1.6%). Chiral analysis of T. distichum essential oil on an ethyl substituted ß-cyclodextrin capillary column revealed the presence of a-pinene in racemic form, with an enantiomeric ratio of 49.3% for (1R)-(+)- and 50.7% for (1S)-(-)-α-pinene.

Compositional variability and antifungal potentials of ocimum basilicum, O. tenuiflorum, O. gratissimum and O. kilimandscharicum essential oils against Rhizoctonia solani and Choanephora cucurbitarum.

The composition of hydrodistilled essential oils of Ocimum basilicum L. (four chemovariants), O. tenuiflorum L., O. gratissimum L., and O. kilimandscharicum Guerke were analyzed and compared by using capillary gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS). Phenyl propanoids (upto 87.0%) and monoterpenoids (upto 83.3%) were prevalent constituents distributed in the studied Ocimum taxa. The major constituents of the four distinct chemovariants of O. basilicum were methyl chavicol (86.3%), methyl chavicol (61.5%)/linalool (28.6%), citral (65.9%); and linalool (36.1%)/citral (28.8%). Eugenol (66.5% and 78.0%) was the major constituent of O. tenuiflorum and O. gratissimum. Eugenol (34.0%), ß-bisabolene (15.4%), (E)-α-bisabolene (10.9%), methyl chavicol (10.2%) and 1,8-cineole (8.2%) were the major constituents of O. kilimandscharicum. In order to explore the potential for industrial use, the extracted essential oils were assessed for their antifungal potential through poison food technique against two phytopathogens, Rhizoctonia solani and Choanephora cucurbitarum, which cause root and wet rot diseases in various crops. O. tenuiflorum, O. gratissimum, and O. kilimandscharicum exhibited complete growth inhibition against R. solani and C. cucurbitarum after 24 and 48 h of treatment. O. basilicum chemotypes showed variable levels of growth inhibition (63.0%-100%) against these two phytopathogens.

Chemical analysis of volatile oils from West Himalayan Pindrow Fir Abies pindrow.

The essential oil composition of needle and stem oils of Abies pindrow (Royle ex D.Don) Royle, commonly known as Pindrow or West Himalayan Fir, were analyzed by gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Fifty-six constituents, accounting for 96.0% of needle and 83.5% of stem oil composition, were identified. The oils were characterized by a high content of monoterpenoids (68.9%-79.9%), mainly comprised by limonene (21.0%-34.4%), camphene (0.5%-19.9%), alpha-pinene (13.8%-16.8%), myrcene (6.7%-8.3%) and beta-pinene (6.5%-8.6%). Monoterpene hydrocarbons were predominant in both oils, but the quantitative and qualitative composition of the volatile constituents was specific for each part of the tree; and considerable variations in their terpenoid production pattern were also noticed. Results were compared with earlier reported fir species from different geographic regions.

Chemical composition of root aroma of Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter, an endemic and endangered ethnomedicinal plant from Western Ghats, India.

Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter, which belongs to the family Apocynaceae, is a perennial under shrub, endemic to southern Western Ghats, India. The highly aromatic tuberous roots of the D. arayalpathra are used as an effective remedy for peptic ulcer, cancer-like afflictions and as rejuvenating tonic by native tribes. The objective of this study was to characterise the root aroma of D. arayalpathra for possible industrial applications. Hydrodistilled volatile oil of the roots was analysed by gas chromatography-flame ionisation detector and gas chromatography-mass spectrometry. The volatile oil was characterised by the presence of higher amount of an industrially important flavour molecule, 2-hydroxy-4-methoxybenzaldehyde (96.8%) along with some other minor or trace constituents. Owing to characteristic vanillin-like flavour, the root oil of the D. arayalpathra can be explored as a potential substitute of vanillin-aroma in the flavour industry.

Essential oil composition of Aegle marmelos (L.) Correa: chemotypic and seasonal variations.

BACKGROUND: Aegle marmelos (L.) Correa is a sacred medicinal and nutraceutical tree of India. The present study planned to explore the chemotypic and seasonal variability of the leaf essential oil of A. marmelos from north India for proper industrial utilization. RESULTS: The essential oil yield varied from 0.37% to 0.80% in leaves of A. marmelos populations. Analysis of the essential oils by gas chromatography and gas chromatography-mass spectrometry, and the subsequent classification by statistical analysis showed three types of chemical compositions for A. marmelos with significant variations in their terpenoid compositions. Major components of the essential oils were limonene (31.0-90.3%), α-phellandrene (<0.05-43.5%), (E)-ß-ocimene (0.7-7.9%), α-pinene (<0.05-7.5%), (E)-caryophyllene (0.5-5.3%), ß-elemene (<0.05-4.2%) and germacrene B (0.0-3.3%). In addition to this, essential oil of a locally growing A. marmelos population was also investigated for seasonal variations. The essential oil yield in this population varied from 0.37% to 0.82% during different seasons. Major constituents, namely α-phellandrene (35.8-49.8%), limonene (24.7-34.3%), (E)-ß-ocimene (4.2-10.0%) and α-pinene (6.0-8.0%), showed considerable variations due to season of collection. CONCLUSIONS: The growing location and harvesting season had a close relation to yield and quality of A. marmelos leaf essential oil. The results obtained are of significance for determining a suitable time for harvesting A. marmelos leaves.

Silymarin- and melatonin-mediated changes in the expression of selected genes in pesticides-induced Parkinsonism.

Parkinson's disease (PD) is the second most unconcealed neurodegenerative disorder labelled with motor impairments. Two pesticides, manganese ethylene-1,2-bisdithiocarbamate (maneb) and 1,1'-dimethyl-4,4'-bipyridinium dichloride (paraquat), together, are reported to increase the incidence of PD in humans and Parkinsonism in mice. Conversely, silymarin and melatonin, two naturally occurring antioxidants, rescue from maneb- and paraquat-induced Parkinsonism. The study examined silymarin- and melatonin-mediated changes in the expression of selected genes in maneb- and paraquat-induced Parkinsonism employing mouse discover chips microarrays. The mice were treated intraperitoneally (i.p.), daily, with silymarin (40 mg/kg) or melatonin (30 mg/kg) for 9 weeks along with vehicles. Subsets of animals were also treated with maneb (30 mg/kg; i.p.) and paraquat (10 mg/kg; i.p.), twice a week, for 9 weeks. Whilst the expression of genes in the striatum was determined by microarray, the expression of randomly selected transcripts was validated by quantitative real-time polymerase chain reaction (qRT-PCR). Combined maneb- and paraquat-treatment altered the expression of several genes associated with apoptosis, inflammation, cell cycle, cell-signalling, etc. pathways. Silymarin and melatonin significantly resisted the changes in the expression of a few genes related to apoptosis, inflammation, cell cycle, cell-signalling, etc. The expression patterns of seven randomly selected genes were analyzed by qRT-PCR, which were found to follow the similar trends, as observed with microarray. The results obtained from the study thus demonstrate that despite resemblances, silymarin and melatonin differentially offset maneb- and paraquat-induced changes in transcriptome.

Variation in the volatile constituents of different plant parts of Ligusticopsis wallichiana from western Himalaya, India.

The essential oil composition of the leaves, stem, flowers and roots of Ligusticopsis wallichiana (DC.) Pimenov & Kljuykov were analyzed by GC-FID and GC-MS methods. Forty-five constituents, forming 93.2%-97.8% of the oil compositions, were dominated by acetylenic (31.5%-92.8%) compounds and sesquiterpenoids (0.3%-44.4%). The leaf essential oil was mainly composed 3,5-nonadiyne (35.8%), beta-selinene (20.9%), alpha-funebrene (10.1%) and (Z)-falcarinol (6.1%). The stem oil was dominated by acetylenic compounds (73.8%) represented by 3,5-nonadiyne (67.8%) and (Z)-falcarinol (5.7%). On the contrary, the major components of the flower essential oil were sesquiterpenoids (37.5%), such as germacrene D (16.6%), alpha-funebrene (7.4%), and acetylenic compounds (31.5%), such as (Z)-falcarinol (21.0%) and 3,5-nonadiyne (10.0%). Monoterpenoids constituted 23.9% of the flower oil with limonene (19.9%) as the single major constituent. The essential oil of the roots was dominated by 3,5-nonadiyne (90.5%). The results showed considerable qualitative and quantitative variations in the essential oil compositions of the different plant parts of L. wallichiana. (Z)-Falcarinol (1.9%-21.0%) and alpha-funebrene (0.1%-10.1%) were reported for the first time from the essential oils of L. wallichiana.

Chemical composition of leaf and root essential oils of Boenninghausenia albiflora Reichb. from northern India.

The leaf and root essential oil composition of Boenninghausenia albiflora Reichb and Meissner (family: Rutaceae), collected from Uttarakhand, India, was analysed by capillary gas chromatography and gas chromatography-mass spectrometry. The major constituents identified in the leaf essential oil were ß-myrcene, (Z)-ß-guaiene, (Z)-ß-ocimene and ß-caryophyllene, whereas bicyclogermacrene, α-terpinyl acetate, geijerene and ß-copaene-4α-ol were identified as the major constituents of the root essential oil. This is the first time that the chemical compositions of leaf and root essential oils of B. albiflora have been investigated in detail. The results show significant qualitative and quantitative variations in leaf and root oil composition.

Variation in the volatile constituents of Artemisia annua var. CIM-Arogya during plant ontogeny.

The essential oils yield and composition of the aerial parts of A. annua var. CIM-Arogya grown in Uttarakhand, India were analyzed and compared by capillary GC and GC-MS at different stages of development. The analysis led to the identification of 81 constituents forming 91.0%-97.1% of the essential oils compositions. The essential oil content of the aerial parts was found to vary from 0.3% to 0.7% at different stages of growth. A. annua crop harvested at full flowering and seed setting stage gave higher yield of essential oil (0.6%, 0.7%) than that harvested at pre flowering (0.5%), late vegetative (0.4%, 0.5%), mid vegetative (0.4%, 0.4%) and early vegetative stages (0.3%, 0.3%). The essential oils at different stages of growth showed monoterpenoids (38.5%-72.0%) and sesquiterpenoids (22.2%-48.2%) as major grouped constituents. The major constituents identified were camphor (22.8%-42.6%), 1,8-cineole (3.7%-8.4%), linalool (<0.1%-11.9%), beta-caryophyllene (2.0%-9.2%), (E)-beta-farnesene (1.3%-8.5%), germacrene D (0.5%-7.3%) and 1-epi-cubenol (0.7%-5.2%) in essential oil samples collected at different crop stages.

Essential oil composition of Thymus serpyllum cultivated in the Kumaon region of western Himalaya, India.

The hydrodistilled essential oil of aerial parts of Thymus serpyllum L. (Lamiaceae), cultivated in the Kumaon region of western Himalaya was analyzed by GC and GC-MS. Twenty-nine compounds, representing 91.8% of the oil, were identified. The major components were thymol (58.8%), p-cymene (5.7%), thymol methyl ether (4.0%), borneol (3.8%), sabinene (3.4%), gamma-terpinene (3.4%) and carvacrol methyl ether (3.2%).