Synthesis, Antimicrobial Activities, and Molecular Modeling Studies of Agents for the Sortase A Enzyme.

Sortase A (SrtA) is an attractive target for developing new anti-infective drugs that aim to interfere with essential virulence mechanisms, such as adhesion to host cells and biofilm formation. Herein, twenty hydroxy, nitro, bromo, fluoro, and methoxy substituted chalcone compounds were synthesized, antimicrobial activities and molecular modeling strategies against the SrtA enzyme were investigated. The most active compounds were found to be T2, T4, and T19 against Streptococcus mutans (S. mutans) with MIC values of 1.93, 3.8, 3.94 µg/mL, and docking scores of -6.46, -6.63, -6.73 kcal/mol, respectively. Also, these three active compounds showed better activity than the chlorohexidine (CHX) (MIC value: 4.88 µg/mL, docking score: -6.29 kcal/mol) in both in vitro and in silico. Structural stability and binding free energy analysis of S.mutans SrtA with active compounds were measured by molecular dynamic (MD) simulations throughout 100 nanoseconds (ns) time. It was observed that the stability of the critical interactions between these compounds and the target enzyme was preserved. To prove further, in vivo biological evaluation studies could be conducted for the most promising precursor compounds T2, T4, and T19, and it might open new avenues to the discovery of more potent SrtA inhibitors.

Analysis of Volatile Constituent by Hydrodistillation and Solid-Phase Microextraction Techniques and Antimicrobial and Scolicidal Activities of Essential Oil and Soxhlet Extracts of Ulva rigida grown in Turkey.

In the present study, the volatile composition of Ulva rigida (U. rigida) was elucidated by two different methods. As a result of the identification process of volatile components using the GC/MS-FID instrument, 31 compounds were identified by hydrodistillation (HD) method, and 15 compounds were identified by solid-phase microextraction (SPME) method, elucidating the structure of 99.86 % and 92.65 %, respectively. The most abundant compounds in the essential oil of U. rigida were n-hexadecanoic acid and pentadecanal, while the most abundant compound according to the SPME analysis was heptadecyne, a hydrocarbon compound. In the next step, hexane, dichloromethane, chloroform and methanol solvent extracts of U. rigida were prepared and the antimicrobial activities of the extracts and the essential oil obtained by hydro-distillation as well as the scolicidal activities of the solvent extracts were determined. The results of the antimicrobial activity test of the essential oil showed a high level of activity against Bacillus cereus ATCC 10876 and MRSA. The highest activity was found on the microorganism of Pseudomonas aeruginosa ATCC 9027 in chloroform and methanol extracts of U. rigida. Furthermore, viability detection was performed and the scolicidal effects of the extracts on protoscoleces were assessed. The values of lethal concentration doses (LD50 , LD75 and LD90 ) were calculated using probit analysis.

Antimicrobial and lipase inhibition of essential oil and solvent extracts of Cota tinctoria var. tinctoria and characterization of the essential oil.

The essential oil (EO) of Cota tinctoria var. tinctoria was analyzed using GC-FID / MS. A total of 51 compounds were determined from this taxon, accounting for 99.79% in hydrodistillation. Monoterpenes were the primary chemical class for the volatile organic compounds in the EO (36.1%, 13 compounds). Borneol (18.1%), camphor (14.9%), and ß-pinene (11.3%) were the major components in the EO of C. tinctoria var. tinctoria. The antimicrobial activities of EO and n-hexane, acetonitrile, methanol, and water solvent extracts of the taxon were screened in vitro against ten microorganisms. The EO yielded the best activity (15 mm, 372.5 MIC, 59600 µg/µL) against Mycobacterium smegmatis. The acetonitrile extract was the most active against the Staphylococcus aureus and Bacillus cereus with 274 µg/mL MIC value. IC50 values for the lipase enzyme inhibitory activity of EO and solvent extracts (n-hexane, acetonitrile, methanol, and water) were found to be 59.80 ± 4.3285 µg/mL 68.28 ± 3.1215 µg/mL, 52.60 ± 3.7526 µg/mL, 48.73 ± 2.8265 µg/mL, and 99.50 ± 5.5678 µg/mL, respectively.

The Volatile Chemical Compositions of the Essential Oil/SPME and Enzyme Inhibitory and Radical Scavenging Activities of Solvent Extracts and the Essential oils from Coronilla orientalis Miller and C. varia L. grows in Turkey.

The volatile organic compounds (VOCs) of two Coronilla species (Coronilla orientalis Miller and Coronilla varia L.) obtained by hydrodistillation (HD) and solid phase microextraction (SPME) techniques were identified by GC-FID/MS. The major compounds identified in the SPME extracts were limonene (43.4%) in Coronilla orientalis (C. orientalis), (Z)-ß-ocimene and (E)-ß-ocimene (34.3% and 32.4%) in Coronilla varia (C. varia), whereas, the essential oils of C. orientalis and C. varia were rich with γ-terpinene (22.4%) and phytol (30.7%), respectively. In addition, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), tyrosinase, α-glucosidase enzyme inhibitory, and radical scavenging activities (DPPH) of chloroform, ethyl acetate, methanol, and water extracts, and also essential oils obtained from C. orientalis and C. varia were investigated. The tyrosinase activity was studied at the doses of 25 µg/mL, 50 µg/mL and 100 µg/mL. Tyrosinase inhibition percentage was observed to increase by dose and methanol extracts of the both species were found to have the highest activity. Essential oils of the both species were found to have significant acetylcholinesterase and butyrylcholinesterase inhibition activities. α-Glucosidase enzyme inhibition of the ethyl acetate and water extracts of C. orientalis was determined as 80.11 ± 4.07% and 80.32 ± 3.47% at the 100 µg/mL concentration, respectively. Essential oils, chloroform, ethyl acetate, methanol, and water extracts were determined to have moderate DPPH radical scavenging activities.

α-Glucosidase inhibitory effects of polyphenols from Geranium asphodeloides: Inhibition kinetics and mechanistic insights through in vitro and in silico studies.

Some Geranium species have been used to treat diabetes. To evaluate the scientific basis of this ethnopharmacological use, we aimed to isolate potent α-glucosidase inhibitory metabolites of Geranium asphodeloides Burm. through in vitro bioactivity-guided fractionation. All the tested extracts showed high α-glucosidase inhibitory effect compared to acarbose. Among the tested extracts, the ethyl acetate subextract showed the highest activity with an IC50 value of 0.85 ±â€¯0.01 µM. A hydrolysable tannin, 1,2,4-tri-O-galloyl-ß-d-glucopyranose (1), and five flavonoid glycosides, kaempferol-3-O-α-rhamnopyranoside (2), kaempferol-3-O-α-arabinofuranoside (3), quercetin-3-O-ß-glucopyranoside (4), quercetin-3-O-α-rhamnopyranoside (5), and quercetin-3-O-α-rhamnofuranoside (6), were isolated from the ethyl acetate subextract. Their structures were identified by 1D- and 2D-NMR experiments. 1 exhibited the highest α-glucosidase inhibitory effect, approximately 61 times more potent than positive control, acarbose, with an IC50 value of 0.95 ±â€¯0.07 µM. Also, 2 was more potent than acarbose. An enzyme kinetics analysis revealed that compounds 2, 3 and 4 were competitive, whereas 1 and 6 uncompetitive inhibitors. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolated compounds in the light of the enzyme kinetic studies using various binding sites of the enzyme model.