A 1 H-NMR spectroscopic method for the analysis of thermolabile chemical markers from the essential oil of black turmeric (Curcuma caesia) rhizome: application in post-harvest analysis

Secondary metabolite fingerprinting, anti-pathogenic activity, elite chemotype selection and conservation of Curcuma caesia- an ethnomedicinally underutilized species

Curcuma caesia Roxb. is an ethnomedicinally important, essential oil (EO) yielding aromatic plant. A total of twelve accessions of this plant rhizome were collected from six different agro-climatic zones of West Bengal, India and evaluated for their antimicrobial activities against eight disease-causing, multi-drug-resistant pathogenic strains of urinary-tract infection and respiratory-tract infection. The EO and extracts demonstrated antibacterial activity, with the highest inhibition zone of 18.00 ± 0.08 and 17.50 ± 0.14 mm against Klebsiella pneumoniae by accession 06, even where all the broad-spectrum antibiotics failed to respond. In this study, we employed high-performance thin-layer chromatography (HPTLC) to quantify curcumin, the primary secondary metabolite of C. caesia, and the highest 0.228 mg/gm of curcumin resulted from accession 06. Hence, on the basis of all aspects, accession 06 was identified as the elite chemotype among all twelve accessions. The chemical profiling of EO from accession 06 was done using gas chromatography-mass spectroscopy (GC-MS). Conceivably, about 13 medicinally significant compounds were detected. As this plant species is seasonal and has difficulties in conventional breeding due to dormancy, it must be conserved through in vitro tissue culture for a steady supply throughout the year in massive amounts for agricultural demand. A maximum number of 19.28 ± 0.37 shoots has been obtained in MS medium fortified with 6-Benzylaminopurine, Kinetin, and Naphthalene acetic acid. The genetic uniformity of the plants has been studied through Start Codon Targeted Polymorphism. Therefore, this study must help meet the need for essential phytoactive compounds through a simple, validated, and reproducible plant tissue culture protocol throughout the year.

Essential Oils as Multicomponent Mixtures and Their Potential for Human Health and Well-Being

Essential oils (EOs) and their individual volatile organic constituents have been an inherent part of our civilization for thousands of years. They are widely used as fragrances in perfumes and cosmetics and contribute to a healthy diet, but also act as active ingredients of pharmaceutical products. Their antibacterial, antiviral, and anti-inflammatory properties have qualified EOs early on for both, the causal and symptomatic therapy of a number of diseases, but also for prevention. Obtained from natural, mostly plant materials, EOs constitute a typical example of a multicomponent mixture (more than one constituent substances, MOCS) with up to several hundreds of individual compounds, which in a sophisticated composition make up the property of a particular complete EO. The integrative use of EOs as MOCS will play a major role in human and veterinary medicine now and in the future and is already widely used in some cases, e.g., in aromatherapy for the treatment of psychosomatic complaints, for inhalation in the treatment of respiratory diseases, or topically administered to manage adverse skin diseases. The diversity of molecules with different functionalities exhibits a broad range of multiple physical and chemical properties, which are the base of their multi-target activity as opposed to single isolated compounds. Whether and how such a broad-spectrum effect is reflected in natural mixtures and which kind of pharmacological potential they provide will be considered in the context of ONE Health in more detail in this review.

Thermolabile essential oils, aromas and flavours: Degradation pathways, effect of thermal processing and alteration of sensory quality

Plant-based aroma chemicals, constituting the essential oils play a great role as the natural flavours and preservatives in the food industries. Many of these metabolites are susceptible to degradation under heat (i.e. thermolabile aroma chemicals) which may influence the organoleptic properties of the end-products e.g. essential oil, oleoresin, dry herb, tea and packaged juice. The current review identified in total 42 thermolabile aroma and/or flavour molecules belonging to monoterpenoids, sesquiterpenoids and phenolics. The probable pathway of their degradation and its promoting conditions were also described. Degradation pathways were categorized into five major classes including oxidation, C-C bond cleavage, elimination, hydrolysis and rearrangement. Numerous evidences were cited in support of the thermosensitivity of these phytochemicals under pyrolytic, thermal heating or gas chromatographic conditions. Various post-harvest processes involved in the manufacturing such as drying and distillation of the crops or thermal treatment of the food-products for storage were highlighted as the root cause of degradation. The influence of thermolabile aroma chemicals to maintain the sensory quality of the end-products such as citrus juices, floral oils and thermally cooked foods was discussed in detail. In the present article, detailed insight into the chemical and sensory aspects of thermosensitive aromas and flavours was provided, covering the period from 1990 up to 2020.

Quantitative Determination of Acrolein in Cider by 1H NMR Spectrometry

Acrolein occasionally appears in cider, completely spoiling its quality due to its bitter taste. It is crucial to detect it in the early steps, before the taste is severely affected, to apply the appropriate treatment. A simple and rapid analytical method to determine this compound in cider is therefore desirable. In this work, a quantitative determination method of acrolein in cider is proposed using the proton nuclear magnetic resonance technique (¹H NMR). Acrolein produces a doublet signal in the spectrum at 9.49 ppm, whose area is used to determine the concentration of this compound. 3-(trimethylsilyl)-2,2,3,3-d⁴-propionic acid sodium salt is added to the cider as a reference for 0.00 ppm and 1,3,5-benzenetricarboxylic acid as an internal standard for acrolein determination. The method is validated by gas chromatography (GC). There is a good correlation between the acrolein concentrations obtained by ¹H NMR and by gas chromatography in different commercial ciders (Pearson coefficient 0.9994). The 95% confidence interval for the intercept is 0.15 ± 0.49 (includes 0) and for the slope is 0.98 ± 0.03 (includes 1). When applying the paired t test, no significant difference is observed. The proposed method is direct, and no prior derivatization is needed.

Study of Anti-oxidant, Anti-inflammatory, Genotoxicity, and Antimicrobial Activities and Analysis of Different Constituents found in Rhizome Essential Oil of Curcuma caesia Roxb., Collected from North East India

BACKGROUND

This investigation was designed to evaluate the chemical composition, antioxidant, anti-inflammatory, genotoxicity, and antimicrobial activities of Curcuma caesia Roxb rhizome essential oil.

METHODS

Gas Chromatography/Mass Spectroscopy (GC/MS) analysis was performed to determine the chemical composition, standard antioxidative test DPPH assay, reducing power assay, in vitro antiinflammatory activity (egg albumin denaturation, protease inhibitory assay) by using standard methods. Similarly, antimicrobial activity was tested using the disc diffusion method, minimum inhibitory concentration ability (MIC); while to test genotoxicity, Allium cepa assay was used.

RESULTS

GC/MS analysis revealed eucalyptol (28.55%), epicurzerenone (19.62%), and camphor (21.73%) as the major components of C. caesia rhizome essential oil. Potent antioxidant (IC50= 48.08±0.003 μg/mL), anti-inflammatory (IC50= 121.7±0.0013 μg/mL), and antimicrobial activities of the essential oil were recorded better than the standard drugs Fluconazole for fungus and Ciprofloxacin for bacteria. The essential oil also possessed a strong antibacterial effect against two tested bacterial strains B. subtilis and B. cereus with 7.5 μg/mL MIC value, while for fungal strains the essential oil was most effective against S. cereviaceae with an MIC value of 2.5 μg/mL. All the data were recorded in triplicates. Allium cepa assay revealed minor genotoxicity with mitotic index, MI= 27.70%; chromosome aberration, A= 1.1% of C. caesia rhizome essential oil.

CONCLUSION

C. caesia rhizome essential oil possesses potent antioxidant, anti-inflammatory, and antimicrobial properties with negligible genotoxicity. Hence, the present study is highly significant for the utilization of rhizome of C. caesia, a high-value ethnopharmacological plant for advanced R & D and commercial application.

Antitumor, Antiviral, and Anti-Inflammatory Efficacy of Essential Oils from Atractylodes macrocephala Koidz. Produced with Different Processing Methods

Atractylodes macrocephala Koidz. has been used as an invigorating spleen drug for eliminating dampness and phlegm in China. According to recent researches, different processing methods may affect the drug efficacy, so we collected A. macrocephala from the Zhejiang Province, produced with different processing methods, crude A. macrocephala (CA) and bran-processed A. macrocephala (BA), then analyzed its essential oils (EOs) by GC/MS. The results showed 34 components representing 98.44% of the total EOs of CA were identified, and 46 components representing 98.02% of the total EOs of BA were identified. Atractylone is the main component in A. macrocephala. Compared with CA, BA has 46 detected compounds, 28 of which were identical, and 6 undetected compounds. Pharmacodynamic results revealed that the EOs of CA and atractylone exhibited more effective anticancer activity in HepG2, MCG803, and HCT-116 cells than the EOs of BA; while the EOs of BA exhibited simple antiviral effect on viruses H3N2, both the EOs and atractylone show anti-inflammatory activity by inhibiting the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in ANA-1 cells.