Detection progress of selected drugs in TLC

Potential for application of direct thrombin inhibitors isolated from Euphorbia resinifera O.Berg latex in fibrin clot formation

Direct thrombin inhibitors (designated as EuRL-DTIs) were partially purified from ethanol extracts of Euphorbia resinifera O.Berg latex. The obtained EuRL-DTIs comprised four major compounds: two isomers of phenolic compounds (C19H26O12) and two amide compounds (tentatively identified as C24H44N4O4 and C36H66N6O6), as identified by liquid chromatography and electrospray ionisation quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, and/or nuclear magnetic resonance (NMR) spectroscopy. The effects of EuRL-DTIs on human thrombin-induced fibrin clot production were analysed using thrombin time, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), synchrotron radiation X-ray tomographic microscopy (SRXTM), and scanning electron microscopy (SEM). Kinetic studies revealed that EuRL-DTIs inhibited human thrombin from cleaving the chromogenic substrate S2238, with a Ki of 3.7 μg/mL, in a non-competitive inhibition manner. All results supported the hypothesis that the EuRL-DTIs directly abolished thrombin activity in the production of fibrin clots without requiring a cofactor. The cytotoxicity test showed that EuRL-DTIs were nontoxic to normal human foetal lung fibroblasts (IMR-90). Thus, EuRL-DTIs have potential as antithrombotic agents for application as drugs for thrombosis treatments or in medical devices such as coating surgical sutures.

Phytochemical Characterization and Synergistic Antibacterial Effects of Colebrookea Oppositifolia Essential Oil as Adjuvants to Modern Antibiotics in Combating Drug Resistance

Background

The global threat of multi-drug-resistant bacteria has severely limited the options available for effective antibiotics. This study focuses on the antimicrobial activity and phytochemical characterization of C. oppositifolia extracts, aiming to identify novel plant-based therapeutic agents.

Methods

C. oppositifolia specimens-leaves and inflorescence. Specimens were cleaned, sterilized, dried, and ground into a fine powder. Extracts were obtained using methanol and petroleum ether via a Soxhlet apparatus, followed by fractionation with chloroform, n-butanol, and ethyl acetate. Volatile oil was extracted through hydro distillation using a Clevenger apparatus. Phytochemical analysis was conducted to identify bioactive compounds. Biophysical techniques, including UV-visible spectrophotometry, TLC, HPLC, GC-MS, FTIR, and NMR, were employed for characterization. Antimicrobial activity was tested against S. aureus ATCC25922 and E. coli ATCC25922 using agar well and disc diffusion methods, and synergistic effects were assessed with erythromycin and amoxicillin.

Results

Methanol extract exhibited bacteriostatic activity with inhibition zones of 13.0 ± 0.2 mm for both S. aureus and E. coli. Petroleum ether, chloroform, n-butanol, and ethyl acetate fractions showed varying inhibition zones. Erythromycin demonstrated bactericidal activity, which was enhanced synergistically when combined with methanol extract and volatile oil, increasing inhibition zones against S. aureus. Phytochemical analysis identified phenols, flavonoids, tannins, coumarins, alkaloids, terpenoids, saponins, and glycosides. FTIR analysis revealed functional groups such as amines, aldehydes, nitriles, alkenes, and sulfones. GC-MS identified 24 compounds, with α-pinene, caryophyllene, and carene as major components. NMR spectra indicated no complex formation between oils and antibiotics, suggesting the compounds act as synergists.

Conclusion

The C. oppositifolia extracts possess significant antimicrobial activity and synergistic potential, particularly against S. aureus. The presence of various bioactive compounds suggests a promising role in developing new plant-based therapeutics.

Standardization and preliminary characterization of an ayurvedic stress-relieving head massage oil of Nardostachys jatamansi DC

BACKGROUND

Jatamansi/Nardostachys jatamansi (NJ) is an important aromatic shrub widely used by Ayurvedic practitioners for centuries due to its usefulness in intellect-enhancing (Medhya), strengthening (Balya), and skin disorders. Several classical dosage forms like hot or cold infusion, decoction, distillate, powders, etc. have been mentioned for NJ. Clinical trials of Jatamansi Oil (JO) as a head massage conducted by clinicians and therapists have shown encouraging results in de-stressing/stress management of cancer patients through head anointing treatment.

OBJECTIVE

Such effective proprietary formulation needs assessment of its characteristics using modern analytical technologies to comprehend the Ayurvedic concept of dermal pharmacology.

MATERIALS AND METHODS

Triplicate batches of JO were prepared by evaporating its decoction in sesame oil (SO). Basic physicochemical analysis of the raw material, in-process samples, and finished products was carried out to develop a monograph. Further, raw SO and finished product JO were subjected to TLC, and extracted in hexane and dichloromethane separately for Gas Chromatography-Mass Spectrometry (GC-MS) analysis to profile several bioactive molecules from NJ in the final product, JO.

RESULTS

Standard Operating Procedure was developed and a basic monograph was prepared for JO. GC-MS analysis revealed several phytocompounds dissolved/dispersed in SO after processing, while 18 additional distinct peaks were observed in JO as compared to SO.

CONCLUSION

This preliminary analysis supports the Ayurvedic concept of lipid-based formulations. The plausible phytocompounds anticipated based on retention times can be further quantified and studied for their probable action as anointing treatment. A detailed experimental strategy for understanding the phytochemical changes during the entire process needs to be planned and performed.

Antimicrobial Activity against Foodborne Pathogens and Antioxidant Activity of Plant Leaves Traditionally Used as Food Packaging

In accordance with Thai wisdom, indigenous plant leaves have been used as food packaging to preserve freshness. Many studies have demonstrated that both antioxidant and antimicrobial activities contribute to protecting food from spoilage. Hence, the ethanolic extracts of leaves from selected plants traditionally used as food packaging, including Nelumbo nucifera (1), Cocos nucifera (2), Nypa fruticans (3), Nepenthes mirabilis (4), Dendrocalamus asper (5), Cephalostachyum pergracile (6), Musa balbisiana (7), and Piper sarmentosum (8), were investigated to determine whether they have antioxidant and antimicrobial activities against spoilage microorganisms and foodborne pathogens that might be beneficial for food quality. Extracts 1-4 exhibited high phenolic content at 82.18-115.15 mg GAE/g and high antioxidant capacity on DPPH, FRAP and SRSA assay at 14.71-34.28 μg/mL, 342.92-551.38 μmol Fe²⁺/g, and 11.19-38.97 μg/mL, respectively, while leaf extracts 5-8 showed lower phenolic content at 34.43-50.08 mg GAE/g and lower antioxidant capacity on DPPH, FRAP, and SRSA at 46.70-142.16 μg/mL, 54.57-191.78 μmol Fe²⁺/g, and 69.05->120 μg/mL, respectively. Extracts 1-4 possessed antimicrobial activities against food-relevant bacteria, including Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. Only N. mirabilis extract (4) showed antimicrobial activities against Salmonella enterica subsp. enterica serovar Abony and Candida albicans. Extracts 5-8 showed slight antimicrobial activities against B. cereus and E. coli. As the growth and activity of microorganisms are the main cause of food spoilage, N. fruticans (3) was selected for bioassay-guided isolation to obtain 3-O-caffeoyl shikimic acid (I), isoorientin (II) and isovitexin (III), which are responsible for its antimicrobial activity against foodborne pathogens. N. fruticans was identified as a new source of natural antimicrobial compounds I-III, among which 3-O-caffeoyl shikimic acid was proven to show antimicrobial activity for the first time. These findings support the use of leaves for wrapping food and protecting food against oxidation and foodborne pathogens through their antioxidant and antimicrobial activities, respectively. Thus, leaves could be used as a natural packaging material and natural preservative.

Thin Layer Chromatographic Method for Detection of Conventional Drug Adulterants in Herbal Products

Commercially available conventional drugs have been used to adulterate herbal products. Considering the rapid growth of herbal products’ market, it is essential to screen herbal products for the presence of conventional drugs. Simple analytical methods are needed for the rapid screening of conventional drugs that are likely to be adulterated in herbal products. Thin layer chromatography (TLC) methods for screening twelve conventional drugs in herbal products have been developed and applied. The analytes were extracted from herbal products using acetonitrile:methanol:acetic acid:water (4:4:1:1, v/v). Solvent mixture of dichloromethane:ethyl acetate:methanol (75:15:10, v/v) separated well trimethoprim, sildenafil, paracetamol, and sulfamethoxazole while pyrimethamine, metronidazole, and sulfadoxine were well separated by dichloromethane:ethyl acetate:methanol (77.5:12.5:10, v/v). In addition, acetyl salicylic acid, ibuprofen, diclofenac, quinine, and lumefantrine were well separated by ethyl acetate:methanol:30% ammonia (75:22.5:2.5, v/v). Chromatographic separations were found to be highly reproducible, and more than 10 samples can be analysed in one run. The method was applied in the screening of 229 herbal products. Consequently, 24.0% of the samples contained one adulterant, while 21.4% contained at least two adulterants. All conventional drugs detected in herbal products were not mentioned on the labels and therefore the consumers are kept unaware of their side effects and health problems. Further studies for confirming and quantitatively determining the adulterants in a wide range of products as well as a systematic toxicological analysis of the adulterants in herbal products are recommended.

Quantification of Grapiprant and Its Stability Testing under Changing Environmental Conditions

Grapiprant is a new analgesic and anti-inflammatory drug belonging to the piprant class, approved in 2016 by the FDA Veterinary Medicine Center for the treatment of pain and inflammation associated with osteoarthritis in dogs. It acts as a highly selective antagonist of the EP4 receptor, one of the four prostaglandin E2 (PGE2) receptor subtypes. It has been shown to have anti-inflammatory effects in rat models of acute and chronic inflammation and clinical studies in people with osteoarthritis. The current state of knowledge suggests the possibility of using it in oncological therapy. The manuscript presents the development of conditions for the identification and quantitative determination of grapiprant by thin-layer chromatography with densitometric detection. The optimal separation of the substance occurs using silica gel 60F254 chromatographic plates and the mobile phase containing ethyl acetate-toluene-butylamine. Validation (according to ICH requirements) showed that the developed method is characterized by straightness of results in a wide concentration range with the limit of detection of 146.65 µg/mL. The %RSD values of the precision and accuracy confirm the sensitivity and reliability of the developed procedure. Next, the method was used for quantification of grapiprant in a pharmaceutical preparation, and for stability studies under various environmental conditions. Additionally, the mass studies were carried out on the stressed samples using the UPLC-MS/MS method. The degradation products were primarily characterized by comparing their mass fragmentation profiles with those of the drug. The results indicated a potential degradation pathway for grapiprant.

An Evaluation of Aluminum Tolerant Pseudomonas aeruginosa A7 for In Vivo Suppression of Fusarium Wilt of Chickpea Caused by Fusarium oxysporum f. sp. ciceris and Growth Promotion of Chickpea

Chickpea wilt, caused by Fusarium oxysporum f. sp. ciceris, is a disease that decreases chickpea productivity and quality and can reduce its yield by as much as 15%. A newly isolated, moss rhizoid-associated Pseudomonas aeruginosa strain A7, demonstrated strong inhibition of Fusarium oxysporum f. sp. ciceris growth. An in vitro antimicrobial assay revealed A7 to suppress the growth of several fungal and bacterial plant pathogens by secreting secondary metabolites and by producing volatile compounds. In an in vivo pot experiment with Fusarium wilt infection in chickpea, the antagonist A7 exhibited a disease reduction by 77 ± 1.5%, and significantly reduced the disease incidence and severity indexes. Furthermore, A7 promoted chickpea growth in terms of root and shoot length and dry biomass during pot assay. The strain exhibited several traits associated with plant growth promotion, extracellular enzymatic production, and stress tolerance. Under aluminum stress conditions, in vitro growth of chickpea plants by A7 resulted in a significant increase in root length and plant biomass production. Additionally, hallmark genes for antibiotics production were identified in A7. The methanol extract of strain A7 demonstrated antimicrobial activity, leading to the identification of various antimicrobial compounds based on retention time and molecular weight. These findings strongly suggest that the strain’s significant biocontrol potential and plant growth enhancement could be a potential environmentally friendly process in agricultural crop production.

Lipase-catalyzed one-step regioselective synthesis of 1,2-dioctanoylgalloylglycerol in a solvent-free system: Optimization of reaction conditions and structural elucidation

A multi-functional galloylated structured lipid, 1,2-dioctanoylgalloylglycerol (DOGG), was synthesized enzymatically via a regioselective transesterification of propyl gallate and trioctanoate using an immobilized food-grade Candida antarctica lipase B (Lipozyme® 435) as the biocatalyst under solvent-free condition. The variables that affect the reaction, including reaction temperature, substrate ratio, reaction time, and enzyme load, were evaluated and optimized using Taguchi method and response surface methodology. Both methods predicted the same optimal reaction condition, resulting in a 68.8 ± 1.3% DOGG yield with reaction selectivity of 82.9 ± 0.6% at 90 °C, 25/1 trioctanoate/PG (mol/mol), 72 h reaction, and 25% enzyme load relative to the total substrate weight. The structure of the reaction product was elucidated using NMR spectroscopy and ESI-HRMS, confirming the regioselectivity of the reaction. Enzyme retained 50% of its activity after 5 cycles of reuse. It is feasible to synthesize DOGG as a potential antioxidant and nutraceutical using Lipozyme® 435.

The value of coupling thin-layer chromatography to mass spectrometry in lipid research - a review

Mass spectrometry has emerged as an extremely powerful analytical tool, which is widely used in many fields. This broad application range became possible with the invention of MALDI and ESI as "soft ionization" techniques that keep fragmentation of the analyte to a minimum. However, when these techniques are applied to mixture analysis, less-sensitively detectable compounds may be suppressed by more sensitively detectable compounds, a process called "ion suppression". Thus, previous separation of the mixture into the individual lipid classes is necessary to be able to detect all compounds. This review summarizes the current knowledge in the field of combined TLC/MS and discusses the most important strengths and weaknesses of the different MS (particularly ionization) techniques with respect to phospholipids. This comprises techniques such as MALDI and ESI, but less established approaches such as plasma desorption will be also discussed.

A cost-effective and sensitive TLC-densitometric identification of meloxicam

The influence of different chromatographic conditions and the process of spot visualization on determining the limit of detection as well as quantification (LOD and LOQ) of meloxicam by TLC-densitometric technique was estimated. Of all chromatographic conditions tested, the lowest limiting values, thus the best sensitivity, in the NP-TLC system was achieved on silica gel 60F254 and neutral aluminum oxide plates developed with the mobile phase consisting of ethyl acetate/toluene/n-butylamine (2:2:1, V/V/V). In the case of the RP-TLC method, a mixture of methanol/water (8:2, V/V) enabled densitometric detection of meloxicam at the lowest concentration level on RP-8F254 and RP-18F254 plates. Additionally, the smallest LOD value of meloxicam ensured crystalline violet and gentian violet as visualization agents on silica gel 60F254 and neutral aluminum oxide 150F254 plates, resp. Comparison of the densitometrically obtained spectra of meloxicam drug and its standard after the use of appropriate visualization agents could be a good and cheap alternative tool for the identification of meloxicam as an active pharmaceutical ingredient.

ANTIOXIDANT ACTIVITY of THE SECONDARY METABOLITES PRODUCED by ENDOPHYTIC FUNGI ISOLATED from JERUJU (Acanthus ilicifolius L.) PLANT

Twelve endophytic fungi were isolated from Jeruju plant. Three of which have the best antioxidant activity, namely Culvularia lunata DJS1, Diaporthe phaseolorum DJS2, and Colletotrichum siamense BJS4. The fungi can produce secondary metabolites that have the potential as antioxidant compounds. This study aims to isolate the antioxidant compound using a chromatography column and test the antioxidant activity using DPPH method. Isolation of secondary metabolites produced 40 eluates. The IC50 value of DJS111 and BJS42 eluates were 10.20 µg/ml and 20.89 µg/ml, which is an antioxidant compound with very strong activity. The IC50 value of DJS24 eluate was 54.45 µg/ml, which is strong antioxidant activity. DJS111 eluate has antioxidant activity that approaches to ascorbic acid as a standart antioxidant compound (7.76µg/ml). From TLC, DJS111 contains flavonoid compound and DJS24 and BJS42 contain terpenoid compound.

Rapid Screening of Antimicrobial Synthetic Peptides

Increasing resistance to conventional antibiotics among microorganisms is one of the leading problems of medicine nowadays. Antimicrobial peptides are compounds exhibiting both antibacterial and antifungal activities. However, it is difficult to predict whether a designed new compound would exhibit any biological activity. Moreover, purification of the peptides is one of the most time-consuming and expensive steps of the synthesis that sometimes leads to unnecessary loss of solvents and reagents. In our study we have developed a thin-layer chromatography (TLC) direct bioautography technique for rapid determination of antimicrobial activity of peptides without the necessity of high-performance liquid chromatography purification. In this assay, crude peptides were applied and separated on a TLC plate. Then, pre-prepared plates were dipped into microbial suspension and incubated under optimum conditions for bacteria and fungi as well. The activity of the tested compounds was visualized by spraying the TLC plates with a cell viability reagent, resazurin (7-hydroxy-3H-phenoxazin-3-one 10-oxide). Effectiveness of this assay was compared with minimal inhibitory concentration results obtained by broth microdilution assay. Interestingly, so far such a screening method has not been applied for this group of compounds.