Essential Oil Composition Analysis of Cymbopogon Species from Eastern Nepal by GC-MS and Chiral GC-MS, and Antimicrobial Activity of Some Major Compounds.

Cymbopogon species essential oil (EO) carries significant importance in pharmaceuticals, aromatherapy, food, etc. The chemical compositions of Cymbopogon spp. Viz. Cymbopogon winterianus (citronella) Cymbopogon citratus (lemongrass), and Cymbopogon martini (palmarosa) were analyzed by gas chromatography−mass spectrometry (GC-MS), enantiomeric distribution by chiral GC-MS, and antimicrobial activities of some selected pure major compound and root and leaves EOs of citronella. The EO of leaves of Cymbopogon spp. showed comparatively higher yield than roots or other parts. Contrary to citral (neral and geranial) being a predominant compound of Cymbopogon spp., α-elemol (53.1%), α-elemol (29.5%), geraniol (37.1%), and citral (90.4%) were detected as major compounds of the root, root hair with stalk, leaf, and root stalk with shoot of citronella EO, respectively. Palmarosa leaves' EO contains neral (36.1%) and geranial (53.1) as the major compounds. In the roots of palmarosa EO, the prime components were α-elemol (31.5%), geranial (25.0%), and neral (16.6%). Similarly, lemongrass leaves' EO contains geraniol (76.6%) and geranyl acetate (15.2%) as major compounds, while the root EO contains a higher amount of geraniol (87.9%) and lower amount of geranyl acetate (4.4%). This study reports for the first time chiral terpenoids from Cymbopogon spp. EOs. Chiral GC-MS gave specific enantiomeric distributions of nine, six, and five chiral terpenoids in the root, root stalk with a shoot, and leaves of citronella EOs, respectively. Likewise, four and three chiral terpenoids in the root and leaves of lemongrass oil followed by two chiral terpenoids in the leaves and root of palmarosa EOs each. Additionally, the root and leaves' EOs of citronella exhibit noticeable activity on bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and fungus such as Candida albicans, Microsporum canis, and Trichophyton mentagrophytes. So, geranial-, neral-, geraniol-, and citronellal-rich EOs can be used as an alternative antimicrobial agent.

Thermochemical study of Cr(VI) sequestration onto chemically modified Areca catechu and its recovery by desorptive precipitation method.

A new biosorbent for Cr(VI) sequestration was investigated from betel nut waste (BNW), Areca catechu, by H2SO4 charring. Aqueous insolubility and Cr(VI) uptake capacity of native BNW were potentially improved after H2SO4 modification due to cross-linking reaction of betel nut cellulose, thereby creating suitable complexation sites for Cr(VI) ion removal. Langmuir isotherm and pseudo second order (PSO) kinetic models described well with the experimental data. A trace amount of Cr(VI) was effectively removed below the safe drinking water standard (WHO, 0.05 mg/L) using charred BNW (CBNW). The negative value of ΔG° evaluated for all the temperatures suggested the spontaneous nature of Cr(VI) sequestration and positive value of ΔH° (42.43±0.13 kJ/mol) confirmed an endothermic reaction. Co-existing NO 3 - , Cl-, Na+ and Zn2+ ions showed negligible interferences, whereas SO 4 2 - and PO 4 3 - notably reduced Cr(VI) uptake capacity of CBNW. More than 98% of adsorbed Cr(VI) was desorbed using 1M NaOH solution. A light yellow precipitate of BaCrO4 was recovered from the desorbed solution after precipitation with BaCl2 solution. Therefore, the CBNW biosorbent investigated in this work is expected to be a promising material for Cr(VI) sequestration and its recovery from polluted water.

Comparison of Volatile Constituents Present in Commercial and Lab-Distilled Frankincense (Boswellia carteri) Essential Oils for Authentication.

A comparative analysis of the chemical constituents present in twenty-one commercial and two lab-distilled frankincense (Boswellia carteri) essential oils was carried out using gas chromatography-mass spectrometry (GC-MS) and chiral gas chromatography-mass spectrometry (CGC-MS) for authentication. Out of the twenty-one commercial samples, six were adulterated with synthetic limonene, three were contaminated with synthetic octyl acetate, three were adulterated with castor oil, and two samples each were contaminated with frankincense resin and Boswellia occulta species, respectively, and one was contaminated with the Boswellia serrata species. Additionally, one sample was contaminated with phthalates as well as a cheap essential oil with similar compositions. Furthermore, one sample was adulterated with copaiba resin and frankincense resin in combination with synthetic octyl acetate. Additionally, one was contaminated with Boswellia serrata species, which was further adulterated with castor oil and frankincense resin. To the best of our knowledge, this is the first report to compare the enantiomeric distribution of chiral terpenoids present in commercial frankincense essential oil with lab-distilled frankincense oil for authentication. The CGC-MS analysis showed the presence of a total of eight chiral terpenoids in lab-distilled frankincense essential oils, which can be used as chemical fingerprints for the authentication of frankincense essential oil.

Analysis of Volatile Constituents in Curcuma Species, viz. C. aeruginosa, C. zedoaria, and C. longa, from Nepal.

The genus Curcuma, composed of 93 species mainly originating from Asia, Australia, and South America, has been used for medicinal purposes, aromatic, and nutritional values as well as cosmetic. It plays a vital role in flavoring and coloring as well as exhibiting therapeutic agents against different diseases. Nepalese farmers are unaware of the essential oil compositions of Curcuma species, viz. C. aeruginosa, C. zedoaria, and C. longa. The investigation of these three essential oils provides insight into their potential as cash crops and earns a reasonable return from their production. The essential oils were obtained from the rhizomes of each plant by hydrodistillation and subjected to Gas Chromatography/Mass Spectrometry (GC−MS) analysis to identify its volatile chemical constituents as well as chiral GC-MS to identify the enantiomeric distribution of chiral terpenoids. The order of extraction yields were C. longa (0.89%) > C. zedoaria (0.74%) > C. aeruginosa (0.37%). In total, the presence of 65, 98, and 84 compounds were identified in C. longa, C. zedoaria, and C. aeruginosa, representing 95.82%, 81.55%, and 92.59% of the total oil, respectively. The most abundant compounds in C. longa essential oils were ar-turmerone (25.5%), α-turmerone (24.4%), ß-turmerone (14.0%), terpinolene (7.2%), ß-sesquiphellandrene (5.1%), α-zingiberene (4.8%), ß-caryophyllene (2.9%), ar-curcumene (1.6%) and 1,8-cineole (1.3%). The most dominant compounds in C. zedoaria were curzerenone (21.5%), 1,8-cineole (19.6%), curzerene (6.2%), trans-ß-Elemene (5.1%), camphor (2.6%), and germacrone (2.3%). The major components in C. aeruginosa were curzerenone (59.6%), germacrone (5.3%), curzerene (4.7%), camphor (3.6%), trans-ß-Elemene (2.6%), and ß-eudesmol (1.6%). C. zedoaria, and C. aeruginosa essential oil from Nepal for the very first time. This study reports for the first time chiral terpenoids from C. aeruginosa, C. zedoaria, and C. longa essential oil. A chemical blueprint of these essential oils could also be used as a tool for identification and quality assessment.

Volatile Constituent Analysis of Wintergreen Essential Oil and Comparison with Synthetic Methyl Salicylate for Authentication.

A comparative analysis of Gaultheria fragrantissima (Ericaceae) essential oils based on geographical location, distillation time, and varying distillation conditions was carried out, and their compositions were evaluated by gas chromatography-mass spectrometry (GC-MS), chiral GC-MS, and gas chromatography-flame ionization detection (GC-FID). In addition, each of seven commercial wintergreen essential oil samples from Nepal and China were analyzed. The highest extraction yield was 1.48% and the maximum number of compounds identified in natural wintergreen oil was twenty-two. Based on distillation time, the maximum numbers of identified compounds are present in 120 min. Linalool, phenol, vetispirane, and ethyl salicylate were present in commercial wintergreen oils both from Nepal and China. The presence of compounds such as elsholtzia ketone and ß-dehydroelsholtzia ketone in the China samples represented a significant difference in wintergreen oil between the two geographical sources. Dimethyl 2-hydroxyterephthalate is a well-known synthetic marker for wintergreen oil when synthesis is carried out using salicylic acid, but the synthetic marker was absent while using acetylsalicylic acid as a precursor during synthesis. Adulteration analysis of wintergreen oil showed an increase in the concentration of dimethyl 2-hydroxyterephthalate, whereas the concentrations of minor components decreased and methyl salicylate remained unchanged. To the best of our knowledge, this is the first report of the enantioselective analysis of wintergreen essential oil. Furthermore, three samples showed notable antibacterial activity against Staphylococcus epidermidis, with an MIC value of 156.3 µg/mL. Similarly, one sample showed effectiveness against Aspergillus niger (MIC = 78.1 µg/mL).

The Chemical Profiling of Essential Oils from Different Tissues of Cinnamomum camphora L. and Their Antimicrobial Activities.

Cinnamomum camphora L. is grown as an ornamental plant, used as raw material for furniture, as a source of camphor, and its essential oil can be used as an important source for perfume as well as alternative medicine. A comparative investigation of essential oil compositions and antimicrobial activities of different tissues of C. camphora was carried out. The essential oils were extracted by hydrodistillation with a Clevenger apparatus and their compositions were evaluated through gas chromatography-mass spectrometry (GC-MS), enantiomeric composition by chiral GC-MS, and antimicrobial properties were assayed by measuring minimum inhibitory concentrations (MICs). Different plant tissues had different extraction yields, with the leaf having the highest yield. GC-MS analysis revealed the presence of 18, 75, 87, 67, 67, and 74 compounds in leaf, branch, wood, root, leaf/branch, and leaf/branch/wood, respectively. The significance of combining tissues is to enable extraction of commercial quality essential oils without the need to separate them. The oxygenated monoterpene camphor was the major component in all tissues of C. camphora except for safrole in the root. With chiral GC-MS, the enantiomeric distributions of 12, 12, 13, 14, and 14 chiral compounds in branch, wood, root, leaf/branch, and leaf/branch/wood, respectively, were determined. The variation in composition and enantiomeric distribution in the different tissues of C. camphora may be attributed to the different defense requirements of these tissues. The wood essential oil showed effective antibacterial activity against Serratia marcescens with an MIC of 39.1 µg/mL. Similarly, the mixture of leaf/branch/wood essential oils displayed good antifungal activity against Aspergillus niger and Aspergillus fumigatus while the leaf essential oil was notably active against Trichophyton rubrum. C. camphora essential oils showed variable antimicrobial activities against dermal and pulmonary-borne microbes.

Systematic Development of Structured Semi-interactive Stroke Prevention Package for Secondary Stroke Prevention.

BACKGROUND: Lack of compliance to medication and uncontrolled risk factors are associated with increased risk of recurrent stroke and acute coronary syndrome in patients with recent stroke. Multimodal patient education may be a strategy to improve the compliance to medication and early adoption of nonpharmacological measures to reduce the vascular risk factor burden in patients with stroke. We thus aim to develop multilingual short messaging services (SMS), print, and audio-visual secondary stroke prevention patient education package. The efficacy of the package will be tested in a randomized control trial to prevent major cardiovascular and cerebrovascular events. METHODS: In the formative stage, intervention materials (SMS, video, and workbook) were developed. In the acceptability stage, the package was independently assessed and modified by the stakeholders involved in the stroke patient care and local language experts. The modified stroke prevention package was tested for implementation issues (implementation stage). RESULTS: Sixty-nine SMS, six videos, and workbook with 11 chapters with 15 activities were developed in English language with a mean ± SD SMOG index of 9.1 ± 0.4. A total of 355 stakeholders including patients (24.8%), caregivers (24.8%), doctors (10.4%), nurses (14.1%), local language experts (2.8%), physiotherapists (13.2%), and research coordinators (9.8%) participated in 10 acceptability stage meetings. The mean Patient Education Material Assessment Tool understandability score in all languages for SMS, video scripts, and workbook was 95.2 ± 2.6%, 95.2 ± 4.4%, and 95.3 ± 3.6%, respectively. The patients [n = 20, mean age of 70.3 ± 10.6 years and median interquartile range (IQR) baseline NIHSS 1 (0-3)] or the research coordinators (n = 2) noted no implementation issues at the end of 1 month. CONCLUSION: An implementable complex multilingual patient education material could be developed in a stepwise manner. The efficacy of the package to prevent major adverse cardiovascular events is being tested in the SPRINT INDIA study.