Ursolic acid (UA), which has many biological properties such as anti-cancer, anti-inflammatory and antioxidant, and regulates some pharmacological processes, has been isolated from the flowers, leaves, berries and fruits of many plant species. In this work, UA was purified from the methanol-chloroform crude extract of Nepeta species (N. aristata, N. baytopii, N. italica, N. trachonitica, N. stenantha) using a silica gel column with chloroform or ethyl acetate solvents via bioactivity-guided isolation. The most active sub-fractions were determined under bioactivities using antioxidant and DNA protection activities and enzyme inhibitions. UA was purified from these fractions and its structure was elucidated by NMR spectroscopy techniques. The highest amount of UA was found in N. stenantha (8.53 mg UA/g), while the lowest amount of UA was found in N. trachonitica (1.92 mg UA/g). The bioactivities of UA were evaluated with antioxidant and DNA protection activities, enzyme inhibitions, kinetics and interactions. The inhibition values (IC₅₀) of α-amylase, α-glucosidase, urease, CA, tyrosinase, lipase, AChE, and BChE were determined between 5.08 and 181.96 µM. In contrast, K_i values of enzyme inhibition kinetics were observed between 0.04 and 0.20 mM. In addition, K_i values of these enzymes for enzyme-UA interactions were calculated as 0.38, 0.86, 0.45, 1.01, 0.23, 0.41, 0.01 and 2.24 µM, respectively. It is supported that UA can be widely used as a good antioxidant against oxidative damage, an effective DNA protector against genetic diseases, and a suitable inhibitor for metabolizing enzymes.Communicated by Ramaswamy H. Sarma.

1,5,9-epideoxyloganic acid (ELA) was isolated from the aerial parts of endemic Nepeta aristata Boiss Et Kotschy Ex Boiss crude extract (methanol:chloroform) using silica gel (hexane, chloroform, ethyl acetate, and methanol) and sephadex LH-20 (65% methanol-35% chloroform) columns. Activity-guided isolation was performed on methanol sub-fractions with DNA protection and enzyme inhibitory activities, and then the ELA was purified by prep-HPLC. The ELA structure, bio-guided isolate, was determined via ¹H NMR, ¹³C NMR, and MS spectrometry. ELA's enzyme inhibition and DNA protection activities were investigated and compared with standard drugs. The inhibition capacity of ELA against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), urease, carbonic anhydrase (CA), α-glucosidase, α-amylase, lipase, and tyrosinase enzymes was evaluated by kinetic and molecular docking results. The ELA displayed the best inhibitory activity on AChE, BChE, α-glucosidase, urease, α-amylase, and tyrosinase with IC₅₀ values of 2.53 ± 0.27, 3.75 ± 0.11, 3.98 ± 0.07, 4.40 ± 0.01, 6.43 ± 0.54 and 7.39 ± 0.00 µg/mL, respectively. ELA acted as a competitive inhibitor against BChE and α-glucosidase and a non-competitive inhibitor against AChE. The ELA's binding affinity values on AChE, BChE, and α-glucosidase were -7.70, -8.50, and -8.30 kcal/mol, respectively. DNA protection activity of the ELA molecule was determined as 57.53% for form I and 53.57% for form II. In conclusion, the inhibitory activity of ELA demonstrated its effectiveness in terms of its suitability in the pharmaceutical industry.Communicated by Ramaswamy H. Sarma.

Atriplex nitens Schkuhr (ANS), which grows naturally in arid and semi-arid regions of the world, is highly resistant to drought and salty environments and is used as food and animal feed. This study first performed phytochemical analysis and antioxidant and urease inhibition activities on the obtained methanol crude extract of ANS. The catechin and isoquercitrin were detected as the main compounds according to LC-MS/MS results. Oleic acid methyl ester (31.71%), palmitic acid methyl ester (25.87%), linoleic acid methyl ester (19.61%), and nonacosane (16.81%) were detected in GC-MS/MS analysis of extract. Posphomolybdenum reducing, DPPH˙ scavenging, and urease inhibition activities were found effective at 67.27±23.83, 7.85±0.44 and 6.58±0.48 µg/mL, respectively, of ANS extract. In this investigation, the biological activity and chemical composition of the ANS extract were initially examined. Molecular docking and ADMET prediction were performed on this plant's two most abundant components. It was found that the interaction with urease of isoquercitrin (MolDock score-121.42, binding affinity -8.60, and binding constant 0.62 µM) with urease determined a higher than. These two components have a negligible potential for toxicity. The Boiled Egg plot indicates a significant GIa for catechin. However, isoquercitrin does not exhibit BBB or GLa permeability. It was determined that the main component isoquercitrine may be effective against gastric diseases, and it was supported that it was not observed in the BBB and GLa systems.

Nepetanudoside B (NNB) was isolated from aerial parts of endemic Nepeta aristata crude extract (CH₃OH-CHCl₃) using silica gel (n-hexane, methanol, ethyl acetate, and dichlorometane, respectively) and sephadex LH-20 (65% Methanol-35% Chloroform) column chromatographies. Preparative-HPLC was used to purify NNB after activity-guided isolation of methanol sub-fractions with enzyme inhibitory and DNA protective properties. The NNB was determined using ¹H,¹³C, COSY, HSQC, HMBC, and LC-MS/MS. The study compared the effects of NNB with conventional drugs in terms of its ability to inhibit enzymes such as urease, α-amylase, carbonic anhydrase (CA), lipase, α-glucosidase, and tyrosinase, as well as its ability to protect DNA. Enzyme kinetic and molecular docking were also used to evaluate this. NNB exhibited the best inhibitory activity on urease (1.28 ± 0.00 µg/mL), lipase (5.83 ± 0.10 µg/mL), BChE (3.73 ± 0.46 µg/mL), tyrosinase (7.39 ± 0.00 µg/mL), α-glucosidase (10.95 ± 0.00 µg/mL), α-amylase (22.11 ± 1.03 µg/mL) and AChE (25.68 ± 3.32 µg/mL), respectively. NNB has higher MolDock scores with binding energy in α-glucosidase (-233) and BChE (-8.90 kcal/mol). In enzyme kinetics studies, it was determined that urease, AChE, α-glucosidase, lipase, and CA were non-competitive , while BChE and tyrosinase were competitive inhibition mechanisms. Their K_i values were calculated as 0.09, 0.24, 0.09, 0.10, 0.08, 0.05, and 0.07 mM, respectively. Molecular dynamics simulation studies were performed for the interactions of NNB-BChE with MM/PBSA binding free energey RMSD, RMSF, Rg, SASA, and also the number of hydrogen bonds was calculated. The suitability and effectiveness of NNB have been proven in the food and pharmaceutical industries. The NNB molecule may lead to development studies as a BChE inhibitor.Communicated by Ramaswamy H. Sarma.