Phytochemical Analysis, Biological Activities, and Docking of Phenolics from Shoot Cultures of Hypericum perforatum L. Transformed by Agrobacterium rhizogenes.

Hypericum perforatum transformed shoot lines (TSL) regenerated from corresponding hairy roots and non-transformed shoots (NTS) were comparatively evaluated for their phenolic compound contents and in vitro inhibitory capacity against target enzymes (monoamine oxidase-A, cholinesterases, tyrosinase, α-amylase, α-glucosidase, lipase, and cholesterol esterase). Molecular docking was conducted to assess the contribution of dominant phenolic compounds to the enzyme-inhibitory properties of TSL samples. The TSL extracts represent a rich source of chlorogenic acid, epicatechin and procyanidins, quercetin aglycone and glycosides, anthocyanins, naphthodianthrones, acyl-phloroglucinols, and xanthones. Concerning in vitro bioactivity assays, TSL displayed significantly higher acetylcholinesterase, tyrosinase, α-amylase, pancreatic lipase, and cholesterol esterase inhibitory properties compared to NTS, implying their neuroprotective, antidiabetic, and antiobesity potential. The docking data revealed that pseudohypericin, hyperforin, cadensin G, epicatechin, and chlorogenic acid are superior inhibitors of selected enzymes, exhibiting the lowest binding energy of ligand-receptor complexes. Present data indicate that H. perforatum transformed shoots might be recognized as an excellent biotechnological system for producing phenolic compounds with multiple health benefits.

UHPLC-Q-TOF analysis of pyrrolizidine alkaloids in North-Macedonian honey.

Honey contaminated with pyrrolizidine alkaloids (PAs) could pose a risk for human consumption, being a widely consumed food product. A fast and simple LC/MS method for the analysis of pyrrolizidine alkaloids in honey was optimised to collect occurrence data. The extraction efficiency was evaluated by a systematic study of multiple solvent mixtures and clean-up procedures. The best results for PA extraction were obtained using a formic acid/methanol mixture with subsequent clean-up by the QuEChERS method, resulting in a mean recovery range of 91.8-102%. The method validation showed satisfactory intra-day (RSD < 5.1%) and inter-day precision (RSD < 9.1%). The proposed method was applied to 14 samples. A total of six PAs and two N-oxides were detected, with levels between 89 and 8188 µg/kg. This assessment highlights the potential risk of intoxication and the need for further investigations regarding an effective quality system for manufacturers to control PAs in honey.

Extraction, Distribution and Diversity of Phenolic Compounds in Most Widespread Boraginaceae Species from Macedonia.

A systematic study of extraction efficiency of polyphenolic compounds from the most widespread Boraginaceae species was carried out. The optimal extraction was achieved with 50 % (V/V) methanol for phenolic acids and flavonoids, 0.2 % (V/V) HCl in 50 % (V/V) methanol for anthocyanins and pure water for flavan-3-ols. The distribution and diversity of polyphenolic compounds in plant material obtained from wild-growing Anchusa officinalis, Cynoglossum creticum Mill., Echium vulgare, Echium italicum, and Onosma heterophylla Griseb. species from Macedonia was also assessed. These widespread Boraginaceae species contain phenolic acid derivatives, flavonoids, flavan-3-ols and anthocyanins and in total 31 of them were identified, from which 22 were first identified in the representative species, and 6,8-di-C-glucosides of apigenin and luteolin were identified for the first time in Boraginaceae. The profiles of polyphenolic compounds for each sample were obtained and their phytochemical profile established. The potential for further bioactivity studies of Anchusa officinalis and Cynoglossum creticum containing up to 24577.05 µg/g and 14304.15 µg/g of total polyphenols were assumed to be highest, followed by Echium vulgare (from 6382.61 to 14114.33 µg/g), Onosma heterophylla (9463.97 µg/g) and Echium (4108.14 µg/g).

Assay of urinary excretion of polyphenols after ingestion of a cup of mountain tea (Sideritis scardica) measured by HPLC-DAD-ESI-MS/MS.

Flavonoids and phenolic acid metabolites excreted in human urine after ingestion of Sideritis scardica decoction with characterized polyphenolic composition were studied. A feeding study was carried out with 10 human volunteers, and urine samples were collected for 24 h after ingestion of the Sidertis decoction. Polyphenol metabolites were identified and quantified in urine samples by HPLC with tandem mass spectrometric detection. Thirty-one different metabolites of hypolaetin, methylhypolaetin, isoscutellarein, methylisoscutellarein, and apigenin and 32 phenolic acid metabolites were detected and quantified using a method validated for this purpose. The urinary excretion of polyphenol metabolites corresponded to 5% (n/n) of the intake of polyphenols from the Sideritis decoction. Flavonoid metabolites were dominant in urine samples with 87-94% of total polyphenolic metabolites content. The most abundant metabolites were methylhypolaetin and methylisoscutellarein glucuronides. Urinary excretion of isoscutellarein (35.61%) was 10 times higher than that of hypolaetin (3.67%). Apigenin also showed high urinary excretion (32.46%).

Phenolic profile of dark-grown and photoperiod-exposed Hypericum perforatum L. Hairy root cultures.

Hypericum perforatum L. is a medicinal plant considered as an important natural source of secondary metabolites with a wide range of pharmacological attributes. Hairy roots (HR) were induced from root segments of in vitro grown seedlings from H. perforatum after cocultivation with Agrobacterium rhizogenes A4. Investigations have been made to study the production of phenolic compounds in dark-grown (HR1) and photoperiod-exposed (HR2) cultures. The chromatographic analysis of phenolic acids, flavonols, flavan-3-ols, and xanthones revealed marked differences between HR1 and HR2 cultures. The production of quinic acid, kaempferol, and seven identified xanthones was increased in HR2. Moreover, HR2 showed a capability for de novo biosynthesis of two phenolic acids (3-p-coumaroylquinic acid and 3-feruloylquinic acid), three flavonol glycosides (kaempferol hexoside, hyperoside, and quercetin acetylglycoside), and five xanthones (tetrahydroxy-one-methoxyxanthone, 1,3,5-trihydroxy-6-methoxyxanthone, 1,3,5,6-tetrahydroxy-2-prenylxanthone, paxanthone, and banaxanthone E). On the other side, HR1 cultures were better producers of flavan-3-ols (catechin, epicatechin, and proanthocyanidin dimers) than HR2. This is the first comparative study on phenolic profile of H. perforatum HR cultures grown under dark and photoperiod conditions.