Evaluation of Biological Potency of two Endemic Species Integrated with in vitro and in silico Approches: LC-MS/MS Analysis of the Plants.

In the present study, the main phytochemical components of endemic plant extracts and inhibitory potency were screened related to different biological activities. Seven compounds were quantified, and cyanidin-3-o-glucoside was the dominant secondary metabolite in the extract of plants. The extract from P. asiae-minoris (PAM) exhibited the best enzyme inhibitory activity against BChE (1.73±0.23 µg mL-1 ), tyrosinase (2.47±0.28 µg mL-1 ), α-glucosidase (5.28±0.66 µg mL-1 ), AChE (8.66±0.86 µg mL-1 ), and ACE (19.27±1.02 µg mL-1 ). In vitro antioxidant assay, PAM extract possessed the highest activity in respect of DPPH radical scavenging (24.29±0.23 µg/mL), ABTS⋅+ scavenging (13.50±0.27 µg/mL) and FRAP reducing power (1.56±0.01 µmol TE/g extract). MIC values ranged from 1-8 mg/mL for antibacterial ability, and the PAM extract showed a stronger effect for B. subtilis, E. faecalis, and E. coli at 1 mg/mL. The antiproliferative ability of A. bartinense (AB) extract demonstrated a suppressive effect (IC50 : 70.26 µg/mL) for pancreatic cancer cell lines. According to the affinity scores analysis, the cyanidin-3-o-glucoside demonstrated the lowest docking scores against ACE, AChE, BChE, and collagenase. It was found that the PAM extract exhibited better inhibitory capabilities than A. bartinense. The P. asiae-minoris plant, reported to be in the Critically Endangered (CR) category, should be conserved by culturing, considering its biological abilities.

New potentiometric PVC membrane electrode for Ferric Reduction Antioxidant Power assay.

In this study, a fast, reproducible and simple-to-apply a new potentiometric determination method was developed for the evaluation of iron (III) reducing power (FRAP), one of the antioxidant capacity tests. For this purpose, an all-solid-state contact iron (III)-selective poly vinyl chloride (PVC) membrane electrode (FRAP-PME) has been developed. In the structure of the developed polymeric membrane electrode (PME), Fe(II)-quercetin compound was used as the active ingredient. It was obtained that PME exhibits a linear potentiometric behavior against the concentration change of Fe(III) ion between 1.0 × 10-1-1.0 × 10-5 mol L-1 and the detection limit is 8.0 × 10-6 molL-1. PME showed a very rapid potential response (40-45 s) and was found to have a very high selectivity towards Fe(III) ion in the presence of other species that might interfere. The proposed potentiometric method has been successfully applied to evaluate the iron (III) reducing power of plant extracts.

LC-ESI-MS/MS Chemical Characterization, Antioxidant and Antidiabetic Properties of Propolis Extracted with Organic Solvents from Eastern Anatolia Region.

Geographic conditions (altitude, climate, and local flora) lead to significant differences in the chemical composition of propolis. Therefore, more research is needed for propolis in different geographical regions. So, the aim of this study was to evaluate the phenolic profile, total phenolic content, antioxidant, and antidiabetic properties of Pülümür propolis from Turkey. Methanol (MeOH), chloroform (CHCl3 ), and hexane extracts of propolis were analyzed. LC-ESI-MS/MS analysis of the extracts showed that the most abundant phenolic compound is caffeic acid in the MeOH extract (2943.12±11.12 µg phenolics/g extract), while on the other hand, CHCl3 extract had the highest total phenolic content (125.75±1.02 mg GAE/g extract). Antioxidant activity was measured using ABTS and DPPH assays, whereas CHCl3 extract (IC50 =6.35±0.11 and 28.84±0.10 µg/mL, respectively) and MeOH extracts (IC50 =5.04±0.07 and 28.80±0.09 µg/mL, respectively) showed relatively high antioxidant activity. The MeOH extract showed better antidiabetic activity than the standard compound, acarbose (IC50 =0.544 and 0.805 mg/mL, respectively).

Antiproliferative and cytotoxic effects of bioactive compounds isolated from Onosma bourgaei.

Onosma species have been used commonly for traditional medicine for years due to their bioactive compounds content. Onosma bourgaei aerial part was extracted with hexane and methanol successively. The methanol extract was subjected to chromatographic techniques to isolate allantoin (1), 3,4-dihydroxybenzaldehyde (2), luteolin-7-O-glucoside (3), apigenin-7-O-ß-glucoside (4), diosmetin-7-O-ß-glucoside (5), rosmarinic acid (6), and globoidnan A (7). The structure of isolated compounds were identified by spectroscopic techniques such as 1D-NMR, 2D-NMR, FTIR, and LC-TOF/MS/MS. Antiproliferative activity of extract and natural compounds were carried out using HeLa (human epithelial cervix adenocarcinoma, ATCC® CCL-2™), HT29 (human colorectal adenocarcinoma, ATCC® HTB38™), MCF7 (human mammary gland adenocarcinoma, ATCC® HTB22™), and A549 (human lung carcinoma, ATCC® CCL185™) cancerous cells and normal cells, FL (human epithelial amnion cell, ATCC® CCL62™). Lactate dehydrogenase (LDH) was performed for cytotoxicity. The compounds, 4, 6, and 7 displayed the strong antiproliferative activity against corresponding cell lines. Apigenin-7-O-ß-glucoside (4) revealed the excellent activity on HeLa, HT29, A549, and MCF6 cancer cell lines with the values of (IC50, µM) 167.3, 196.8 181.1, and 203.5, respectively, compared standard compound, cisplatin.

A new potentiometric PVC membrane sensor for the determination of DPPH radical scavenging activity of plant extracts.

In this study, a simple, fast, stable and low-cost potentiometric determination method is recommended for the evaluation of 1,1-diphenyl-1-picrylhydrazil radical (DPPH•) scavenging activity, which is one of the antioxidant activity tests. For this purpose, a new type of solid-state-contact potentiometric polyvinyl chloride (PVC) membrane sensor was developed. Gallic acid compound, which is sensitive to the DPPH•, was used as the active ingredient in the membrane structure of the sensor. The potentiometric behavior of the developed DPPH•-selective PVC membrane sensor was characterized. The detection limit of the developed sensor was obtained as 2.3 µg/mL. The sensor can measure at low volumes with its high selectivity. The measurement results obtained were in accordance with the results of the spectroscopic method in the literature. The developed DPPH•-selective PVC membrane sensor was quickly dipped directly into the plant extracts and successfully used in test measurements of DPPH• scavenging activity.

The interactive effect of aromatic amino acid composition on the accumulation of phenolic compounds and the expression of biosynthesis-related genes in Ocimum basilicum.

Sweet basil (Ocimum basilicum L.), a well-known medicinal and aromatic herb, rich in essential oils and antioxidants (contributed by phenolics), is widely used in traditional medicine. The biosynthesis of phytochemicals occurs via different biochemical pathways, and the expression of selected genes encoding enzymes involved in the formation of phenolic compounds is regulated in response to environmental factors. The synthesis of the compounds is closely interrelated: usually, the products formed in the first reaction steps are used as substrates for the next reactions. The current study attempted a comprehensive overview of the effect of aromatic amino acid composition (AAAs) in Ocimum basilicum in respect to the expression of genes related to the biosynthesis of phenolic compound and their content. The transcript expression levels of EOMT, PAL, CVOMT, HPPR, C4L, EGS, and FLS increased depending on the AAAs concentration compared to the control plants. The highest mRNA accumulation was obtained in EOMT, FLS, and HPPR in the leaves of sweet basil. The expression of the TAT gene in the leaves significantly reduced in response to all AAAs applications compared to untreated groups and it had the lowest transcript accumulation. Eleven individual phenolic compounds were determined in the basil leaves, and the contents of chicoric acid, methyl chavicol, caffeic acid, and vanillic acid increased depending on administered concentration to control (p < 0.05). Additionally, AAAs lead to an incremental change in the amount of chlorogenic acid at 50 and 100 mg kg-1 compared to control plants (p < 0.05). Rutin and rosmarinic acid were detected as the main phenolic compounds in all experimental groups of sweet basil in terms of quantity. However, their amount significantly decreased as compared to control plants based on the increase in AAAs concentrations (p < 0.05). Also, the accumulation of cinnamic acid, eugenol, and quercetin did not significantly change in the leaves of AAAs treated plants compared to control (p < 0.05). When AAAs was applied, total flavonoid content increased in all treatments compared to the control plants, but total phenolic content did not change significantly (p < 0.05). To the best of our knowledge, our work is the first detailed work to evaluate in detail the impact of AAAs on individual phenolic compounds at the phytochemistry and transcriptional levels in the O. basilicum plant. For a detailed understanding of the whole mechanism of phenolic compound regulation, further research is required to fill in some gaps and to provide further clarification.

Isolation, identification of secondary metabolites from Salvia absconditiflora and evaluation of their antioxidative properties.

Salvia absconditiflora Greuter & Burdet (Synonym Salvia cryptantha Montbret & Aucher ex Benth) has been used extensively for traditional medicine. The aerial of plant material was boiled in water then filtrated. The filtrate was partitioned with ethyl acetate and n-butanol sequentially to yield the ethyl acetate and n-butanol extract. A sample of water was lyophilized to yield the water extract. Ethyl acetate extract revealed the highest antioxidant activity and included the most phenolic compounds among the extracts. Hence, ethyl acetate extract was subjected to chromatographic techniques. Ursolic acid (1), crismaritin (2), luteolin (3), rosmarinic acid methyl ester (4), 3,4-dihydroxyl benzaldehyde (protocatechuic aldehyde) (5), caffeic acid (6), apigenin-7-O-ß-glucoside (7), rosmarinic acid (8) and luteolin-7-O-ß-glucoside (9) were isolated and the structures were elucidated by spectroscopic methods including 1D, 2D NMR, and LC-TOF/MS. Cirsimaritin (2), luteolin (3), rosmarinic acid methyl ester (4), rosmarinic acid (8), luteolin-7-O-ß-glucoside (9) displayed the considerable antioxidant activity.

Changes in flavonoid and phenolic acid contents in some Rosa species during ripening.

In this study, fruits of Rosa dumalis, R. canina, and R. villosa were cultivated and harvested at six different time points based on colour changes during the ripening period. Phenolic acid and flavonoid contents in fresh hypanthium were determined by HPLC-DAD. Derivatives of organic acid (gallic, caffeic, p-coumaric, and ferulic acids) and flavonoid (catechin, eriocitrin, rutin, apigenin, quercetin, apigenin-7-O-glucoside and kaempferol) were quantified using calibration curves. Phenolic acid contents of the Rosa species increased nonlinearly depending on the harvesting time. The highest amount of catechin was found at the fifth harvest time point (H-5) ranged from 323 to 472mgkg-1. The highest level of caffeic acid content was found in the R. dumalis ranged from 24 to 77mgkg-1. The total amount of flavonoid increased up to the fifth harvest time point (H-5), whereas the amount of total phenolic acid tended to decrease until the same harvest period.

Isolation and identification of a new neo-clerodane diterpenoid from Teucrium chamaedrys L.

Teucrium chamaedrys L. is an aromatic and medicinal plant used as traditional medicine. Aerial parts of the plant material were dried and extracted with hexane-dichloromethane (extract 1), ethyl acetate-dichloromethane (extract 2) and methanol-dichloromethane (extract 3) in a ratio of 1:1 at rt successively. The solvents were evaporated to give crude extracts. Extract 1 was suspended in water at 60°C then partitioned successively with hexane and ethyl acetate to give hexane and ethyl acetate portions. After the column chromatography (silica gel) of ethyl acetate extract, one new and four known compounds were isolated. The new compound was named as 1(12S,18R)-15,16-epoxy-2ß,6ß-dihydroxy-neo-cleroda-13(16),14-dien-20,l2-olide-l8,l9-hemiacetal (teuchamaedryn D) (4). The known compounds were teucrin A (1), dihydroteugin (2), teucroxide (3), syspirensin A (5). The chromatographic methods were also applied for extract 3 to isolate verbascoside (6) and teucrioside (7). The structure of isolated compounds was elucidated by spectroscopic methods including LC-TOF/MS, 1D NMR and 2D NMR.