Eryngial: An α,ß-unsaturated Fatty Aldehyde as the Major Phytotoxin in Spiny Coriander (Eryngium foetidum L.) Essential Oil.

Weed species many times possess allelochemicals as a part of their survival strategy. These metabolites can be potential targets in search of natural phytotoxins. This study aims to evaluate the phytotoxic ability of fatty aldehyde-rich essential oil from spiny coriander (Eryngium foetidum) leaves, also known as fitweed or spiritweed and to further identify the active phytotoxins. This oil dose-dependently inhibited the wheatgrass coleoptile and radicle growth in multiple bioassays with half maximal inhibitory concentration (IC50) 30.6-56.7 µg/mL, while exhibiting a less pronounced effect on the germination (IC50 181.8 µg/mL). The phytotoxicity assessment of two oil constituents identified eryngial (trans-2-dodecenal), exclusively major fatty aldehydic constituent as the potent growth inhibitor with IC50 in the range 20.8-36.2 µg/mL during an early phase of wheatgrass emergence. Eryngial-inspired screening of eleven saturated fatty aldehydes and alcohols did not find a significantly higher phytotoxic potency. In an open vessel, eryngial as the supplementation in agar medium, dose-dependently inhibited the growth of pre-germinated seeds of one monocot (bermudagrass) and one dicot (green amaranth) weed species with IC50 in the range 23.8-65.4 µg/mL. The current study identified eryngial, an α,ß-unsaturated fatty aldehyde of coriander origin to be a promising phytotoxic candidate for weed control.

Hypothetical biosynthetic pathways of pharmaceutically potential hallucinogenic metabolites in Myristicaceae, mechanistic convergence and co-evolutionary trends in plants and humans.

The family Myristicaceae harbour mind-altering phenylpropanoids like myristicin, elemicin, safrole, tryptamine derivatives such as N,N-dimethyltryptamine (DMT) and 5-methoxy N,N-dimethyltryptamine (5-MeO-DMT) and ß-carbolines such as 1-methyl-6-methoxy-dihydro-ß-carboline and 2-methyl-6-methoxy-1,2,3,4-tetrahydro-ß-carboline. This study aimed to systematically review and propose the hypothetical biosynthetic pathways of hallucinogenic metabolites of Myristicaceae which have the potential to be used pharmaceutically. Relevant publications were retrieved from online databases, including Google Scholar, PubMed Central, Science Direct and the distribution of the hallucinogens among the family was compiled. The review revealed that the biosynthesis of serotonin in plants was catalysed by tryptamine 5-hydroxylase (T5H) and tryptophan 5-hydroxylase (TPH), whereas in invertebrates and vertebrates only by tryptophan 5-hydroxylase (TPH). Indolethylamine-N-methyltransferase catalyses the biosynthesis of DMT in plants and the brains of humans and other mammals. Caffeic acid 3-O-methyltransferase catalyses the biosynthesis of both phenylpropanoids and tryptamines in plants. All the hallucinogenic markers exhibited neuropsychiatric effects in humans as mechanistic convergence. The review noted that DMT, 5-MeO-DMT, and ß-carbolines were natural protectants against both plant stress and neurodegenerative human ailments. The protein sequence data of tryptophan 5-hydroxylase and tryptamine 5-hydroxylase retrieved from NCBI showed a co-evolutionary relationship in between animals and plants on the phylogenetic framework of a Maximum Parsimony tree. The review also demonstrates that the biosynthesis of serotonin, DMT, 5-MeO-DMT, 5-hydroxy dimethyltryptamine, and ß-carbolines in plants, as well as endogenous secretion of these compounds in the brain and blood of humans and rodents, reflects co-evolutionary mutualism in plants and humans.

A membrane targeted multifunctional cationic nanoparticle conjugated fusogenic nanoemulsion (CFusoN): induced membrane depolarization and lipid solubilization to accelerate the killing of Staphylococcus aureus.

Bacterial infections caused by Staphylococcus aureus are one of the growing concerns for human health care management globally. Antibiotic-associated adverse effects and the emergence of bacterial resistant strains necessitate the development of an alternative yet effective approach. Nanoemulsion-based therapy has emerged as a potential therapeutic strategy to combat bacterial infestation. Herein, we designed a cationic metal nanoparticle-conjugated fusogenic nanoemulsion (CFusoN) as a lipid solubilizing nanovesicle for the effective treatment of S. aureus infection with a killing efficiency of 99.999%. The cationic nanoparticle-conjugated nanoemulsion (viz. NECNP) (24.4 ± 2.9 mV) electrostatically bound with the negatively charged bacterial cell membrane (-10.2 ± 3.7 mV) causing alteration of the bacterial surface charge. The fluorometric and flow cytometry studies confirmed the bacterial membrane depolarization and altered cell membrane permeability leading to cell death. The atomic force microscopic studies further demonstrated the damage of the cellular ultrastructure, while the transmission electron microscopic image and membrane lipid solubilization analysis depicted the solubilization of the bacterial membrane lipid bilayer along with the leakage of the intracellular contents. The cell membrane fatty acid analysis revealed that the methyl esters of palmitic acid, stearic acid and octadecadienoic acid isomers were solubilized after the treatment of S. aureus with CFusoN. The bactericidal killing efficiency of CFusoN is proposed to occur through the synergistic efficacy of the targeted attachment of CNP to the bacterial cells along with the lipid solubilization property of NE. Interestingly, NECNP didn't elicit any in vitro hemolytic activity or cytotoxicity against red blood cells (RBCs) and L929 fibroblast cells, respectively, at its bactericidal concentration. Furthermore, a porcine skin wound infection model exhibited the enhanced wound cleansing potency of CFusoN in comparison to the commercially available wound cleansers. The obtained antibacterial activity, biocompatibility and skin wound disinfection efficacy of the NECNP demonstrated the formulation of a cell targeted CFusoN as a promising translatable strategy to combat bacterial infection.

Mushroom mediated selective bioreduction of S-(+)-carvone to cis-(-)-dihydrocarvone: approach towards a safer biocatalysis.

Dihydrocarvone, possessing four stereoisomers is an important flavour and chiral building block in chemical synthesis. Ascomycetes are well known for the selective bioreduction of carvone to dihydrocarvone. Often, these fungi produce mycotoxins which may contaminate the biocatalytic product. Herein, Ganoderma sessile, a polypore mushroom, selectively reduced S-(+)-carvone to cis-(-)-dihydrocarvone (DHC) in its submerged culture. In an optimised condition (0.75 g/L, 18 h, pH 3-5, 30 °C and 150 rpm), 82.7% cis-(-)-DHC was obtained in gas chromatography-mass spectrometry profile of the fermented product. The absolute titre of cis-(-)-DHC in fermentation medium was 0.35 ± 0.01 g/L. However, substrate toxicity (IC50 0.15 g/L) drastically reduced the transformation at higher carvone concentration (≥1.0 g/L). On the other hand, R-(-)-carvone was less selective and efficient in producing the desired isomer i.e. trans-(+)-DHC. G. sessile is the member of a group of non-toxic medicinal mushrooms and may be a safer yet efficient option for producing cis-(-)-DHC biocatalytically.

A high performance thin layer chromatography (HPTLC) method for the quality assessment of citronella oil: application in commercial sample analysis.

Citronella oil, extracted from Cymbopogon species (winterianus and nardus) is a commercially valuable essential oil used in personal-care products and insect repellents. Routine analysis in gas chromatography is incapable of detecting high-boiling adulterants therein. In this study, an HPTLC technique was developed for the absolute quantification of citronellal (characteristic chemical marker) and triglyceride (main constituent of vegetable oil adulterant) in citronella oil for its quality assessment. It was validated in terms of specificity, linearity, sensitivity, accuracy and precision. Further, the developed method was employed to quantify citronellal and triglyceride in twenty commercial samples. The results showed a wide variation in citronellal content (trace to 30.65% w/w) and could differentiate its two chemotypes. Also, it revealed the possibility of vegetable oil adulteration through the detection and quantification of triglyceride in selected samples. It can be a simple and rapid technique for the quality control of citronella oil.

Persephacin Is a Broad-Spectrum Antifungal Aureobasidin Metabolite That Overcomes Intrinsic Resistance in Aspergillus fumigatus.

Fungi pose a persistent threat to humankind with worrying indications that emerging and re-emerging pathogens (e.g., Candida auris, Coccidioides spp., drug-resistant Aspergilli, and more) exhibit resistance to the limited number of approved antifungals. To address this problem, our team is exploring endophytic fungi as a resource for the discovery of new antifungal natural products. The rationale behind this decision is based on evidence that endophytes engage with plants in mutualistic relationships wherein some fungi actively participate by producing chemical defense measures that suppress pathogenic microorganisms. To improve the odds of bioactive metabolite discovery, we developed a new hands-free laser-cutting system capable of generating >50 plant samples per minute that, in turn, enabled our team to prepare and screen large numbers of endophytic fungi. One of the fungal isolates obtained in this way was identified as an Elsinoë sp. that produced a unique aureobasidin analogue, persephacin (1). Some distinctive features of 1 are the absence of both phenylalanine residues combined with the incorporation of a novel amino acid residue, persephanine (9). Compound 1 exhibits potent antifungal effects against a large number of pathogenic yeast (including several clinical C. auris strains), as well as phylogenetically diverse filamentous fungi (e.g., Aspergillus fumigatus). In an ex vivo eye infection model, compound 1 outperformed standard-of-care treatments demonstrating the ability to suppress fluconazole-resistant Candida albicans and A. fumigatus at a concentration (0.1% solution) well below the clinically recommended levels used for fluconazole and natamycin (2% and 5% solutions, respectively). In 3D tissue models for acute dermal and ocular safety, 1 was found to be nontoxic and nonirritating at concentrations required to elicit antifungal activity. Natural product 1 appears to be a promising candidate for further investigation as a broad-spectrum antifungal capable of controlling a range of pathogens that negatively impact human, animal, and plant health.

Chavibetol: major and potent phytotoxin in betel (Piper betle L.) leaf essential oil.

BACKGROUND: Many essential oils and their constituent volatile organic compounds are known to be phytotoxic and potential bioherbicides. This study aims to investigate the phytotoxicity of propenylbenzene-rich essential oils and identify active molecule(s) therein. RESULTS: Five commercially available propenylbenzene-rich oils were screened, of which betel (Piper betle L.) oil was identified as a potent natural phytotoxin. It dose-dependently inhibited wheatgrass (Triticum aestivum) seed germination and growth in water and agar medium with half maximal inhibitory concentration (IC50 ) in the range 23.2-122.7 µg mL-1 . Phytotoxicity-guided fractionation and purification revealed chavibetol as the major and most potent phytotoxic constituent of betel oil, followed by chavibetol acetate. A structure-activity relationship study involving 12 propenylbenzenes indicated the structural and positional importance of aromatic substitutions for the activity. Furthermore, the phytotoxic efficacy of chavibetol was established against wheatgrass germination and growth in water (IC50 15.8-53.4 µg mL-1 ), agar (IC50 34.4-53.6 µg mL-1 ) and aerial (IC50 1.7-4.5 mg L-1 ) media with a more pronounced effect on the radicle. Also, in open phytojars, chavibetol efficiently inhibited the growth of 3-7-day-old bermudagrass (Cynodon dactylon) seedlings when sprayed directly (IC50 2.3-3.4 mg jar-1 ) or supplemented in agar (IC50 116.6-139.1 µg mL-1 ). The growth of pre-germinated green amaranth (Amaranthus viridis) was inhibited more effectively in both application modes (1.2-1.4 mg jar-1 and IC50 26.8-31.4 µg mL-1 respectively). CONCLUSION: The study concluded betel oil as a potent phytotoxic herbal extract and its major constituent chavibetol as a promising volatile phytotoxin for the future management of weeds in their early phase of emergence. © 2023 Society of Chemical Industry.

Biocompatible Nanodiamonds Derived from Coal Washery Rejects: Antioxidant, Antiviral, and Phytotoxic Applications.

Coal washery rejects (CWRs) are a major byproduct produced in coal washery industries. We have chemically derived biocompatible nanodiamonds (NDs) from CWRs toward a wide range of biological applications. The average particle sizes of the derived blue-emitting NDs are found to be in the range of 2-3.5 nm. High-resolution transmission electron microscopy of the derived NDs depicts the crystalline structure with a d-spacing of 0.218 nm, which is attributed to the 100 lattice plane of a cubic diamond. The Fourier infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy (XPS) data revealed that the NDs are substantially functionalized with oxygen-containing functional groups. Interestingly, the CWR-derived NDs exhibit strong antiviral properties (high inhibition of 99.3% with an IC50 value of 7.664 µg/mL) and moderate antioxidant activity that widen the possibility of biomedical applications. In addition, toxicological effects of NDs on the wheatgrass seed germination and seedling growth showed minimal inhibition (<9%) at the highest tested concentration of 300.0 µg/mL. The study also provides intriguing prospects of CWRs for the creation of novel antiviral therapies.

Mushroom-Mediated Reductive Bioconversion of Aldehyde-Rich Essential Oils for Aroma Alteration: A Rose-like Floral Bioflavor from Citronella Oil.

The bioflavors are of high demand in food and beverage industries. The current study identified reductive processes mediated by mushroom species to alter the aroma of aldehyde-rich essential oils in the submerged culture. Neofomitella polyzonata, a polypore mushroom, reduced citronellal and citral in the citronella oil into corresponding alcohols that altered the oil aroma, creating a new bioflavor. The screening with 43 aldehydes showed its broad substrate scope within aromatic and linear aldehydes, yet influenced by the electronic and steric factors. Under an optimized condition, it efficiently converted up to 1.5 g/L citrusy and sharp citronella oil into a terpene alcohol-rich (citronellol and geraniol) floral, sweet, fresh, and rosy oily product within 12 h. The preparative-scale fermentation in the shake flask followed by distillation, an organic solvent-free downstream process, furnished the product in 87.2% w/w yield. Detailed sensory analyses and volatile chemo-profiling established the uniqueness in the product aroma and identified citronellol and geraniol as the key odorants. The chemometric analysis found best compositional similarity of this product with Damask or Turkish rose oils. The preference test for the water flavored with the fermented product (0.001-0.005% v/v) indicated its potential as a rosy bioflavor for the beverages.

A high performance thin layer chromatography (HPTLC) method for the quality assessment of agarwood (Aquilaria malaccensis) oil from Northeast India.

The high-value agarwood oil, largely used in perfumery is generally graded by the traditional method of sensorial assessment. The compositional complexity and variation made its quality control challenging. Besides, non-volatile contaminants and adulterants are the bottlenecks in gas-chromatographic detection. Herein, a HPTLC based technique was developed for the quality assessment of agarwood oil from Northeast India. A 'marker band' (anisylacetone and oxygenated sesquiterpene rich) on HPTLC profile, containing major peaks of the oil and characteristic agarwood aroma was quantified to assess the quality. The developed method was validated in terms of specificity, linearity, sensitivity, recovery and precision. The application of the method in test samples of three different grades indicated a positive correlation between 'marker band' quantity and oil quality. Its abundance in the superior grade oil was >50% and <20% in poor grade. It can be an efficient analytical tool for the quality assessment and grading of agarwood oil.

Altertoxin II, a Highly Effective and Specific Compound against Ewing Sarcoma.

A screening program designed to identify natural products with selective cytotoxic effects against cell lines representing different types of pediatric solid tumors led to the identification of altertoxin II as a highly potent and selective cytotoxin against Ewing sarcoma cell lines. Altertoxin II, but not the related compounds altertoxin I and alteichin, was highly effective against every Ewing sarcoma cell line tested, with an average 25-fold selectivity for these cells as compared to cells representing other pediatric and adult cancers. Mechanism of action studies revealed that altertoxin II causes DNA double-strand breaks, a rapid DNA damage response, and cell cycle accumulation in the S phase. Our studies also demonstrate that the potent effects of altertoxin II are partially dependent on the progression through the cell cycle, because the G1 arrest initiated by a CDK4/6 inhibitor decreased antiproliferative potency more than 10 times. Importantly, the cell-type-selective DNA-damaging effects of altertoxin II in Ewing sarcoma cells occur independently of its ability to bind directly to DNA. Ultimately, we found that altertoxin II has a dose-dependent in vivo antitumor efficacy against a Ewing sarcoma xenograft, suggesting that it has potential as a therapeutic drug lead and will be useful to identify novel targets for Ewing-sarcoma-specific therapies.

Accurate Identification of Bioactive Meliaceae Limonoids by UHPLC-MS/MS Based Structure-Fragment Relationships (SFRs).

Limonoids are bioactive plant specialized metabolites found in the Meliaceae family. The basic limonoids, i.e., azadiradione, epoxyazadiradione, and gedunin have been exploited for various bioactivities and therefore are the potential drug leads for tomorrow. However, their low abundance, structural similarity, and lack of adequate mass fragmentation data have hampered their accurate identification and quantification from various sources. In the present study, basic limonoids such as azadirone, azadiradione, epoxyazadiradione, and gedunin isolated from Neem were utilized for the synthesis of their derivatives and isotopologs. A total of 30 one compounds were used in this study among which five were isolated, two were biotransformed, and 24 were synthesized. Among the synthesized compounds nine are novel compounds including six deuterated analogs/isotopologs which are (1,3-2H)-1,2-dihydro-3ß-hydroxyazadiradione (9), (1,3,16-2H)-1,2-dihydro-3ß-16ß-dihydroxyazadiradione (10), 3ß-hydroxyazadiradione (11), 3ß-16ß-dihydroxyazadiradione (12), (3-2H)-3ß-hydroxyazadiradione (13), (3,16-2H)-3ß-16ß-dihydroxyazadiradione (14), (1,3,7-2H)-1,2-dihydro-3ß-hydroxy-7-deacetylazadiradione (15), 1,2,20,21,22,23-hexahydroazadiradione (17), and (1,3-2H)-1,2-dihydro-3ß-hydroxygedunin (29). These limonoids along with their semisynthesized derivatives were subjected to ultra high performance liquid chromatography mass spectrometry (UHPLC-MS/MS) and the fragmentation pathway was established based on structure-fragment relationships (SFRs), utilizing high resolution MS/MS data. We have developed a most reliable and easily reproducible protocol describing in depth analysis of SFRs based on the structural modifications and synthesis of isotopologs. Also, the MS/MS fragment library of these basic limonoids generated in this study acts as a fingerprint for accurate identification and quantification of limonoids by MS/MS analysis in various plant tissue extracts, phytopharmaceutical formulations and biological samples.

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.

Evaluation of Postharvest Drying, Key Odorants, and Phytotoxins in Plai (Zingiber montanum) Essential Oil.

Plai or cassumunar ginger (Zingiber montanum), mainly distributed in tropical Asia, is an essential oil-bearing rhizomatous crop belonging to the Zingiberaceae family. Rhizomes and essential oil of this herb are used in culinary as flavoring agents, traditional medicines, and aromatherapy. In this study, the effect of different postharvest drying methods (air-, oven-drying at 40 and 60 °C, sun-, microwave-, and freeze-drying) of its sliced rhizome on the essential oil yield, composition, and sensory quality was investigated. The major key odorants and phytotoxins in its essential oil were identified for the first time through sensory- or bioassay-guided fractionation. Although the drying methods did not alter the oil composition significantly, oven-drying at 40 °C and freeze-drying produced the highest oil yield (81.0% of fresh rhizome) while maintaining the sensory quality. 4-Terpineol was found to be the majorly abundant key odorant in its oil through detailed sensory analysis. This oxygenated monoterpene was also demonstrated to be the major phytotoxin negatively affecting seed germination and shoot and root growth of wheatgrass seeds with IC50 values of 0.67, 0.10, and 0.17 mM, respectively. The current study is beneficial for further value addition of this crop in food industries and the agricultural sector.

Nutmegs and wild nutmegs: An update on ethnomedicines, phytochemicals, pharmacology, and toxicity of the Myristicaceae species.

Prized medicinal spice true nutmeg is obtained from Myristica fragrans Houtt. Rest species of the family Myristicaceae are known as wild nutmegs. Nutmegs and wild nutmegs are a rich reservoir of bioactive molecules and used in traditional medicines of Europe, Asia, Africa, America against madness, convulsion, cancer, skin infection, malaria, diarrhea, rheumatism, asthma, cough, cold, as stimulant, tonics, and psychotomimetic agents. Nutmegs are cultivated around the tropics for high-value commercial spice, used in global cuisine. A thorough literature survey of peer-reviewed publications, scientific online databases, authentic webpages, and regulatory guidelines found major phytochemicals namely, terpenes, fatty acids, phenylpropanoids, alkanes, lignans, flavonoids, coumarins, and indole alkaloids. Scientific names, synonyms were verified with www.theplantlist.org. Pharmacological evaluation of extracts and isolated biomarkers showed cholinesterase inhibitory, anxiolytic, neuroprotective, anti-inflammatory, immunomodulatory, antinociceptive, anticancer, antimicrobial, antiprotozoal, antidiabetic, antidiarrhoeal activities, and toxicity through in-vitro, in-vivo studies. Human clinical trials were very few. Most of the pharmacological studies were not conducted as per current guidelines of natural products to ensure repeatability, safety, and translational use in human therapeutics. Rigorous pharmacological evaluation and randomized double-blind clinical trials are recommended to analyze the efficacy and therapeutic potential of nutmeg and wild nutmegs in anxiety, Alzheimer's disease, autism, schizophrenia, stroke, cancer, and others.

A sensitive 1 H NMR spectroscopic method for the quantification of capsaicin and capsaicinoid: morpho-chemical characterisation of chili land races from northeast India.

INTRODUCTION: Proton (1 H) nuclear magnetic resonance (NMR) spectroscopy based analytical method for the quantification of capsaicin (major pungent principle of chili) has certain advantages including short data acquisition time and better structural authentication. Earlier NMR methods are associated with either of the bottlenecks such as low or lack of information on the sensitivity and scope for the quantification of total capsaicinoid. OBJECTIVE: To develop a sensitive 1 H quantitative NMR (qNMR) technique for capsaicin and total capsaicinoid in dry chili and chili oleoresin and to demonstrate its applicability in a real sample set. METHOD: A 1 H qNMR method was developed using benzene as the internal standard for the quantification of capsaicin (terminal methyl signal) as well as total capsaicinoid (benzyl methylene signal) in dry chili and oleoresin and validated in terms of specificity, linearity, sensitivity, accuracy and precision. RESULTS: The developed 1 H qNMR method was specific, sensitive (limit of detection 4.4 µg/mL and limit of quantitation 14.8 µg/mL), linear in the range 0.083-8.33 mg/mL of capsaicin, accurate and precise. The credibility of the developed method was showcased in the morpho-chemical characterisation of commercially available 15 chili land races from northeast India. The analysis identified the land races with a wide range of capsaicin (trace to 1.49% in the dry fruit and trace to 6.21% in the oleoresin w/w) and oleoresin content (3.35-26.78% w/w). CONCLUSION: The standardized 1 H qNMR method facilitated the findings of chemical basis for the selection of chili land races from this region, capable of producing high-yielding oleoresin with intended degree of pungency.

Elaeocarpus floribundus Bl. seeds as a new source of bioactive compounds with promising antioxidant and antimicrobial properties.

The fruits of Elaeocarpus floribundus Bl. (Elaeocarpaceae) are edible and are normally prescribed for treatment of diseases. The medicinal uses of the fruit create considerable quantities of seeds as wastes. In an attempt to valorise this biomass, we studied the antimicrobial and antioxidant activities of the ethanolic seed extract. The extract inhibited the growth of the tested pathogens and was also a very strong scavenger of DPPH free radicals. Consequently, the extract was phytochemically investigated and this study reports the initial isolation of five phenolic compounds from this source. The structures of the isolated compounds were elucidated by spectra analyses including HR-ESI-MS, 1D and 2D NMR experiments. The isolated compounds exhibited a wide range of antimicrobial activities against the tested pathogens. Gallic acid (4) showed the most activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) value of 30 µg/mL, while the MIC values of the antimicrobial standards range between 10 and 35 µg/mL. Compound 4, crude ethanolic extract, and the ethyl acetate fraction were more a potent free radical scavenger of DPPH compared to ascorbic acid. Hence, the seeds of E. floribundus could be considered as a new source of bioactive compounds for pharmaceutical and food-related industries.

A 1H NMR spectroscopic method for the quantification of propenylbenzenes in the essential oils: Evaluation of key odorants, antioxidants and post-harvest drying techniques for Piper betle L.

1H quantitative Nuclear Magnetic Resonance (qNMR) spectroscopy technique has certain advantages such as low-temperature operation, authentic structural prediction and short data acquisition time. In this study, a 1H qNMR method was developed for the analysis of propenylbenzenes (eugenol and seven analogues) in the essential oils, a broadly distributed class of natural flavours. It was validated in terms of specificity (methoxy/acetate signal), linearity (range 0.05-5.00 mg per assay), sensitivity (limit of detection and quantification 4.4 and 14.9 µg/mL respectively), accuracy and precision. The qNMR technique was utilized during the sensory or activity-guided identification of chavibetol as the key odorant and antioxidant in the betel (Piper betle L., Bangla cultivar) oil, a widely consumed chewing stimulant and valuable flavouring agent. The method was also applied for the evaluation of six different post-harvest drying techniques for betel leaves through the quantitative analysis of unambiguously identified propenylbenzene markers (chavibetol, chavibetol acetate and 4-allyl-1,2-phenylene diacetate).

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.

INTRODUCTION: Curcuma caesia (black turmeric), an essential oil-bearing rhizomatous herb has been a part of ethnomedicinal practices in India and southeast Asian countries since ancient time. Oleochemical profile of black turmeric has been investigated previously by gas chromatography coupled to mass spectrometry (GC-MS) technique from different geographical regions showing a large variation in the identity as well as abundance of the constituents. OBJECTIVES: To develop an analytical method for the reliable analysis of essential oil from black turmeric rhizome through identified chemical markers and to show the credibility of the developed method on real samples. METHODS: The essential oil of black turmeric was analysed through proton nuclear magnetic resonance (1 H-NMR) based method using an internal standard. RESULTS: Four thermolabile sesquiterpene markers were unambiguously identified from the essential oil of black turmeric rhizome. GC-MS based analysis produced an erroneous identification of the constituents. A standardised 1 H-NMR spectroscopy based method was developed for the qualitative and quantitative analysis of the identified chemical markers. The developed method was further utilised for analysing the variation in oleochemical profile across multiple batches of harvest and the rhizomes subjected to different post-harvest storage or drying conditions. CONCLUSION: The identified marker molecules and developed 1 H -NMR spectroscopic method might prove to be a useful tool for the analysis of essential oil and quality control of this endangered crop material. Also, the present study provided information on the preferred drying and storage condition of black turmeric rhizome prior to the extraction of essential oil.

Temperature-dependent mucosal permeation kinetics of stigmasterol microspheres: In vivo mice model antioral candidiasis study.

Evaluation of mucosal permeation of stigmasterol from the glutaraldehyde cross linked chitosan microspheres at increasing experimental temperatures was performed. The activation energy of permeation, partition, and diffusion were estimated to understand the permeation kinetic with respect to the temperature. The formulation depicting least activation energy possessed the increased permeation thresholds of drug at the site of application. The encapsulation efficacy and mucoadhesive strength were found to be directly proportional to the polymer-emulsifier ratio. Decreased intensity in crystallography directed the molecular dispersion of microencapsulated drug. The depleted enthalpic phase transition in thermogram affirmed the stigmasterol encapsulation. The sphericity and the size of microspheres were determined by scanning electron photo micrograph. The in vivo quantification of oral Candida infection with different statistical approach and histopathological observation of infected tongue of mice on treatment with the stigmasterol encapsulated microspheres showed significant anti oral candidiasis activity by reduction of fungal colony count and recovery of papillae, reorganization of basal cell layer and newly formed papillae during 21-28 days of treatment.