Subhash C. Joshi

Antioxidant and antibacterial activities of the leaf essential oils of Himalayan Lauraceae species.

The leaf essential oils from seven Himalayan Lauraceae species viz. Neolitsea pallens, Lindera pulcherrima, Dodecadenia grandiflora, Persea duthiei, Persea odoratissima, Persea gamblei and Phoebe lanceolata exhibited potent antioxidant and antibacterial activities. The in vitro antioxidant activity was assessed by using beta-carotene bleaching assay, reducing power, DPPH radical scavenging and inhibition of lipid peroxidation methods. The oils of D. grandiflora and L. pulcherrima showed a potent free radical scavenging activity as evidenced by low IC(50) value for DPPH radical (0.032 mg/ml and 0.087 mg/ml, respectively) and inhibition of lipid peroxidation (in between IC(50)=0.44 mg/ml and IC(50)=0.74 mg/ml, respectively). The oils were tested against three Gram negative (Escherichia coli, Salmonella enterica enterica and Pasturella multocida) and one Gram positive (Staphylococcus aureus) bacteria at different concentrations using disc diffusion and tube dilution methods. The inhibition zones (IZ) and MIC values for bacterial strains were in the range of 8.7-22.0mm and 3.90-31.25 microl/ml, respectively.

Terpenoid diversity in the leaf essential oils of Himalayan Lauraceae species.

The leaf terpenoid compositions of nine Lauraceae species, viz., Neolitsea pallens, Lindera pulcherrima, Dodecadenia grandiflora, Persea duthiei, Persea odoratissima, Persea gamblei, Phoebe lanceolata, Cinnamomum tamala, and Cinnamomum camphora, collected from the Himalayan region (India) were examined by GC, GC/MS, and NMR analyses in order to determine the similarities and differences among their volatile constituents. Furano‐sesquiterpenoids were the principal constituents of N. pallens, L. pulcherrima, and D. grandiflora. (E)‐Nerolidol, limonene, β‐pinene, and α‐pinene were the major constituents of P. duthiei; α‐pinene, sabinene, and β‐caryophyllene were predominant in P. odoratissima, while the oils of P. gamblei and P. lanceolata possessed β‐caryophyllene as common major constituent. C. camphora and C. tamala were marked by the presence of camphor and cinnamaldehyde, respectively. Cluster analysis of the oil composition was carried out in order to discern the differences and similarities within nine species of six genera of Lauraceae.

Chemical Composition of the Essential Oil From Eupatorium adenophorum Spreng

Abstract The GC and GC/MS analysis of the essential oils from the aerial parts of Eupatorium adenophorum collected from different localities of Kumaun and Garhwal revealed the dominant presence of amorph-4-en-7-ol (5.8–17.7%), bornyl acetate (7.6–15.9%), p-cymene (0.1–16.6%), 3-acetoxyamorpha-4,7(11)-dien-8-one (0.3–16.3%), α-phellandrene (1.5–9.6%), camphene (≶0.1–8.9%), α-bisabolol (1.7–7.8%), α-cadinol (0.6–6.2%) and amorph-4,7(11)-dien-8-one (3.2–5.7%). Amorphene derivatives (19.8–41.4%) may be considered as characteristic constituents of E. adenophorum.

Identification, characterization and quantification of a new impurity in deferasirox active pharmaceutical ingredient by LC-ESI-QT/MS/MS.

An unknown impurity was detected in deferasirox drug substance by a newly developed high performance liquid chromatography (HPLC) method. The unknown impurity was identified by liquid chromatography-tandem mass spectrometry using electrospray ionization source and Q-trap mass analyzer (LC-ESI-QT/MS/MS). Based on LC-MS/MS data and knowledge of the synthetic scheme of deferasirox, this impurity was proposed as the regio-isomer of deferasirox. Structural confirmation of this impurity was unambiguously carried out by synthesis followed by characterization using nuclear magnetic resonance (NMR), infrared spectroscopy (IR), mass spectrometry, elemental analysis (EA) and the impurity was confirmed as 2-[3,5-bis(2-hydroxy-phenyl)-[1,2,4]-triazol-1-yl]-benzoic acid (Imp-1). The newly developed method was validated according to ICH guidelines. The resolution between Imp-1 and deferasirox was found to be more than 6.0 and the detection limit of impurities was in the range of 0.0005-0.01%, indicating high selectivity and sensitivity of the newly developed method.

Sesquiterpene Hydrocarbons Rich Essential Oil of Stachys sericea Wall

Abstract The GC and GC-MS analysis of the essential oil of S. sericea Wall. showed dominant presence of sesquiterpene hydrocarbons (79.1 %) with germacrene D (37.7 %), (E)-ß-caryophyllene (17.4 %), ô-cadinene (6.0 %) and (E)-ß-farnesene (3.9 %) as major constituents. (X-Bisabolol (3.0 %) was the major oxygenated sesquiterpenoid along with several minor constituents.

Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI–IT/MS, 1H, 13C and 1H–1H COSY NMR

A new impurity was detected during high performance liquid chromatographic (HPLC) analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI–IT/MS) analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR), 1H–1H correlation spectroscopy (COSY) and infrared spectroscopy (IR). Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.

Isoiridomyrmecin rich essential oil from Nepeta erecta Benth. and its antioxidant activity

The essential oil composition of the aerial parts of Nepeta erecta Benth. (Family: Lamiaceae) from Uttarakhand, India was analysed by capillary gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). A total of 34 constituents were identified representing 94.6% of the oil composition. Oxygenated monoterpenes (74.0%) constituted the major proportion of the oil, dominated by isoiridomyrmecin (70.6%) as a single major constituent. Other significant constituents were caryophyllene oxide (9.6%), β-Bourbonene (2.0%), humulene epoxide II (1.7%) and linalool (1.0%). The in vitro antioxidant activity (AOA) was assessed using β-Carotene bleaching assay, reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and inhibition of lipid peroxidation methods. The oil was found to exhibit AOA by inhibiting β-Carotene bleaching (54.6 ± 2.52%) and by scavenging DPPH free radical (IC50 = 0.74 ± 0.12 mg mL−1). The AOA of the essential oil of N. erecta and its major compound isoiridomyrmecin has not been reported so far.

Antioxidant and antibacterial activities of the leaf essential oil and its constituents furanodienone and curzerenone from Lindera pulcherrima (Nees.) Benth. ex hook. f.

Background: Lindera pulcherrima (Nees.) Benth. ex Hook. f. (Family: Lauraceae), an evergreen shrub, is an important medicinal plant distributed in temperate Himalayan regions. The leaves and bark are used as spice in cold, fever, and cough. Materials and Methods: In this study, the terpenoid composition, antioxidant, and antibacterial activities of the leaf essential oil and its major constituents are being analyzed. Conclusion: The in vitro antioxidant activity showed a potent free radical scavenging activity for the essential oil as evidenced by a low IC50 value for DPPH radical followed by furanodienone (0.087 ± 0.03 and 1.164 ± 0.58 mg/ml respectively) and the inhibition of lipid peroxidation for the oil and furanodienone also followed the same order (IC50 0.74 ± 0.13 and 2.12 ± 0.49 mg/ml, respectively). The oil and the constituents were also tested against three Gram negative (Escherichia coli, Salmonella enterica enterica, and (Pasturella multocida) and one Gram positive (Staphylococcus aureus) bacteria. The essential oil was effective against S. aureus (IZ = 19.0 ± 0.34; MIC 3.90 μl/ml) while furanodienone showed potent activity against E. coli and S. enterica enterica (IZ = 18.0 ± 0.14 and 16.0 ± 0.10 respectively). On the other hand, curzerenone was found to be slightly effective against E. coli (IZ = 10.8 ± 0.52). The MIC value of the essential oil was least against S. aureus (MIC = 3.90 μl/ml) and that of furanodienone against E. coli (MIC = 3.90 μl/ml).

Quality Assessment of Flavour Constituents of Natural and Commercial Cinnamomum tamala Leaves

Abstract The leaf essential oil composition of Cinnamomum tamala (Buch-Ham) Nees & Eberm, collected from different locations of Kumaon Himalaya, were analyzed by GC and GC-MS. (E)-Cinnamaldehyde (23.2–79.9 %), linalool (3.4–30.7 %), (E)-cinnamyl acetate (1.0–11.4 %) and (E)-methyl cinnamate (< 0.1–9.6 %) were detected as major constituents in different samples. The analysis though revealed significant qualitative and quantitative variations in flavour composition of leaves collected from different localities of Kumaon, the materials may be grouped as (E)-Cinnamaldehyde-linalool chemotype.

Essential oil composition of Persea duthiei

Persea duthiei King ex Hook. f. syn. Machilus duthiei King ex Hook. f. is a small or medium-sized evergreen tree widely distributed around Nainital, ascending to 2500 m. The fruit is a globular black drupe. The root stocks are acrid, bitter, pungent, heating, and astringent and are generally used in inflammation, asthma, pain, foul breath, bronchitis, vomiting, and in blood disease [1–3]. Various Persea species have been subjected to chemical investigations in the past. The GC and GC-MS analysis of the leaf oil of P. americana Mill. of Mexican origin revealed estragol (78.1%), α-cubebene (3.6%), methyl eugenol (3.4%), and β-caryophyllene (2.1%) as the major constituents, while its fruit oil was mainly composed of (E)-nerolidol along with lesser amount of β-caryophyllene, β-pinene, trans-β-bergaptene, and β-bisabolene [4, 5]. The leaf essential oil of P. americana Mill from Nigeria showed β-caryophyllene (43.9%) and valencene (16.0%) as the major constituents [6]. The GC and GC-MS analysis of leaf oils of P. indica showed β-caryophyllene (18.0%), germacrene D (15.4%), and (E)-avocadienofuran (16.0%) as the major constituents [7]. Methyl chavicol (78.0%) has been reported as the major constituent from the leaf oil of P. grattissima [8]. The flower oil of P. bombyciana, a host plant for the muga silk worm (Antheraea assama), was mainly dominated by caryophyllene oxide (19.4%), (E)-nerolidol (14.5%), 11-dodecenal (11.2%), and 11-dodecenoic acid (9.8%), while its fruit oil contained transand cis-linalool oxides (15.3%) [9]. The leaf oil of P. bombyciana was characterized by 2-dodecanal (26.5%), decanal (12.5%), 11-dodecenal (8.1%), dodecanoic acid (9.0%), and caryophyllene oxide (7.0%) along with other monoand sesquiterpenoids [10]. Among reports of three Southern-North American Persea species examined by GC and GC-MS, the oil from P. borbonia was dominated by camphor (34.7%) and 1,8-cineole (17.7%), the oil from P. humilis was characterized by camphor (46.9%) and 1,8-cineole (12.7%), and the major constituents of P. palustris were 1,8-cineole (17.0%), p-cymene (14.8%), and camphor (10.6%) [11]. The leaf oil of P. pododenia of Mexican origin was shown to contain α-pinene (20.4%), δ-3-carene (15.9%), and limonene (12.1%) as the major constituents [12]. Diterpenes isolated from P. indica were shown to have potent antifeedant and insecticidal activity [13–16]. Biologically active cytotoxic lignans and neolignans have also been reported from the genus Persea [17–22]. Hussain et al. reported aporphine alkaloids from the root of P. duthiei [23], while there is no report on its essential oil composition. The present analysis of leaf, fruit, and flower oils of P. duthiei resulted in the identification of 41 constituents representing 94.1%, 89.3%, and 90.4% of the total constituents of the leaf, fruit, and flower oils, respectively. The identified constituents of the oils are listed in Table 1 in order of their elution in an Rtx-5 column (30 m × 0.25 mm, 0.25 μm film thickness; 60–210°C, 3°C/min, He gas 1 mL/min). The major compounds (1–6) were isolated and identified by comparing their NMR data (1H and 13C NMR) with those reported in the literature. Thus, the analysis revealed that monoterpene hydrocarbons (36.4%) constituted the major proportion of the leaf oil of P. duthiei, while sesquiterpenoids constituted a greater percentage of fruit and flower oils (83.0% and 84.2%, respectively). The leaf oil consisted of monoterpene hydrocarbons (36.4%) and oxygenated sesquiterpenoids (35.7%) dominated by limonene (10.1%), α-pinene (10.0%), β-pinene (10.0%), p-cymene (3.5%), (E)-nerolidol (13.2%), epi-cubebol (5.8%), β-caryophyllene (5.8%), β-eudesmol (4.0%), and γ-muurolene (4.0%). The fruit and flower oils were mainly dominated by sesquiterpenoids (83.0% and 84.2%, respectively). The fruit oil was characterized by a high content of sesquiterpene alcohols (65.7%) with (E)-nerolidol (24.5%), β-eudesmol (10.9%), selin-11-en-4-α-ol (9.1%), and (Z)-nerolidol (7.7%) as major constituents. (E)-Nerolidol (15.2%) was also the major constituent of the flower oil besides epi-cubebol (11.5%), γ-muurolene (11.5%), and β-caryophyllene (7.9%).