Cell-based bioreporter assay coupled to HPLC micro-fractionation in the evaluation of antimicrobial properties of the basidiomycete fungus Pycnoporus cinnabarinus

Characterisation of α-amylase inhibitors in marigold plants via bioassay-guided high-performance thin-layer chromatography and attenuated total reflectance-Fourier transform infrared spectroscopy

A high-performance thin-layer chromatography with microchemical derivatization and bioassay guided detection was used for bioanalytical profiling of selected marigold plant extracts. Anisaldehyde/sulfuric acid reagent and thymol/sulfuric acid reagent were used to visualize separated components on the chromatograms. Antioxidant activity and α-amylase inhibition were assessed with 2 bioassays, DPPH assay to detect free radical scavengers and starch-iodineassay method to detect compounds that inhibit α-amylase. The highest antioxidant activity of 10.12 μg of gallic acid equivalents (GAE) per 20 µL of extract was measured in extract from Tagetes flowers and the lowest in the extract from Calendula leaves with 5.10 μg of GAE. Multiple zones of α-amylase inhibition were detected. A detailed analysis of the ATR-FTIR spectra from the bands at RF = 0.24 suggest that faradiol esters and saturated fatty acids esters, palmitic acid, myristic acid, and lauric acid are responsible for α-amylase inhibition, unsaturated fatty acids for the band at RF = 0.51 and phytoecdysteroids for the band at RF = 0.53.

Effect-directed analysis of bioactive compounds in Cannabis sativa L. by high-performance thin-layer chromatography

The scientific interest on the plant Cannabis sativa L., and in particular on its non-psychoactive or fibre-type variety (hemp), has been highly increasing in recent years, due to the pharmaceutical and nutraceutical potential of its bioactive compounds. This plant is indeed characterized by a very rich chemical composition, which encompasses different classes of constituents, such as cannabinoids and terpenes. In this context, the bioanalytical testing of hemp extracts can be difficult and time-consuming. Effect-directed analysis (EDA) by the combination of high-performance thin-layer chromatography (HPTLC) with biological and enzymatic assays represents one of the latest tools available for the rapid bioprofiling of complex matrices, such as plant extracts. In this ambit, the aim of this project was the non-targeted screening of inflorescence extracts from ten different hemp varieties for components exhibiting radical scavenging, antibacterial, enzyme inhibiting and estrogen-like effects. By HPTLC-EDA, the hemp samples exhibited strong antibacterial activities against both Gram-positive Bacillus subtilis and especially Gram-negative Aliivibrio fischeri bacteria, and also estrogen-like activity. They also inhibited α- and β-glucosidase, tyrosinase and acetylcholinesterase. The characterization of two prominently multipotent bioactive compound zones was finally achieved by HPTLC-HRMS and preliminary assigned as cannabidiolic acid and cannabidivarinic acid.

Essential oils and functional herbs for healthy aging

As total life expectancy increases, the prevalence of age-related diseases such as diabetes and Alzheimer’s disease is also increasing. Many hypotheses about Alzheimer’s disease have been developed, including cholinergic neuron damage, oxidative stress, and inflammation. Acetylcholine is a major neurotransmitter in the brain and cholinergic deficits leads to cognitive dysfunction and decline. Recent studies have linked diabetes as a risk factor in developing Alzheimer’s disease and other types of dementia. The incidence of patients with type II diabetes and increased levels and activity of α-amylase is higher in patients with dementia. It has been shown that aromatherapy with essential oils from the mint family can improve cognitive performance in Alzheimer’s disease patients. Selected monoterpenoids from these essential oils are reported to inhibit acetylcholinesterase, both in vitro and in vivo. Terpenoids are small, fat-soluble organic molecules that can transfer across nasal mucosa if inhaled, or penetrate through the skin after topical application, enter into the blood and cross the blood-brain barrier. Recent evidence supports the idea that the common constituents of essential oils also inhibit α-amylase, a starch digestive enzyme that plays an important role in the control of diabetes. The mint family is a fragrant plant family that contains most of the culinary herbs found in the Mediterranean diet. The Mediterranean diet is considered to be one of the healthiest diets in the world, and is found to be beneficial not only for the heart but also for the brain. Herbs used in this diet are rich in antioxidants that can prevent oxidative damage caused by free radicals. However, our study shows that they also contain biologically active compounds with potent α-amylase and acetylcholinesterase inhibitory activities. Consumption of fresh herbs can help boost memory and reduce sugar levels in the body. The use of herbs as a functional food could lead to significant improvements in health. Cognitive stimulation with medical food and medical herbs could delay development of cognitive decline, and improve the quality of life of Alzheimer’s disease patients. This effect can be enhanced if combined with aromatherapy, topically or by inhalation, and/or by ingestion. Terpenes and terpenoids, the primary constituents of these essential oils are small, lipid soluble organic molecules that can be absorbed through the skin or across nasal mucosa into the systemic blood circulation. Many terpenes can also cross the blood-brain barrier. Therefore, topical application or inhalation of essential oils will also produce a systemic effect.

Layer chromatography-bioassays directed screening and identification of antibacterial compounds from Scotch thistle

The antibacterial profiling of Onopordum acanthium L. leaf extract and subsequent targeted identification of active compounds is demonstrated. Thin-layer chromatography (TLC) and off-line overpressured layer chromatography (OPLC) coupled with direct bioautography were utilized for investigation of the extract against eight bacterial strains including two plant and three human pathogens and a soil, a marine and a probiotic human gut bacteria. Antibacterial fractions obtaining infusion-transfusion OPLC were transferred to HPLC-MS/MS analysis that resulted in the characterization of three active compounds and two of them were identified as, linoleic and linolenic acid. OPLC method was adopted to preparative-scale flash chromatography for the isolation of the third active compound, which was identified after a further semi-preparative HPLC purification as the germacranolide sesquiterpene lactone onopordopicrin. Pure onopordopicrin exhibited antibacterial activity that was specified as minimal inhibitory concentration in the liquid phase as well.