Chemical profile of the Anatolian Sideritis species with bioactivity studies.

CONTEXT: The genus Sideritis L. (Lamiaceae) is represented by 46 species in Turkey with an 79% endemism ratio, 42 of 46 belonging to the section Empodoclia. OBJECTIVE: In this review article, Sideritis species growing in Turkey have been evaluated for phytochemical constituents and biological activities. METHODS: The data for the isolates, components and extracts of the Anatolian Sideritis species and their bioactivity studies were retrieved from the main databases WoS, Scopus and PubMed from 1975 until 31 December 2022. RESULTS: In this review article, terpenoids, flavonoids, phenolics and other secondary metabolites isolated from Turkish Sideritis species were reported. Anatolian Sideritis species, which primarily consist of monoterpenes and sesquiterpenes, were studied in detail. Sideritis plants are represented by 46 species in Turkey, and 25 of them were investigated for their diterpenoids through isolation or LC-MS studies. Most of the diterpenoids of Turkish Sideritis species have ent-kaurene skeleton, among them linearol, siderol, 7-epicandicandiol and sideridiol were found to be the main compounds. Exceptionally, labdane, pimarane and beyerene diterpenoids were only found in a few species. For phenolics and flavonoids, only 12 species were investigated until now, and they were found to be rich in phenylethanoid glycosides and flavonoid glycosides. In terms of activity, most of the species were tested for antioxidant activity, followed by antimicrobial and anti-ulcer/anti-inflammatory activities. Their cytotoxic, enzyme inhibitory, antinociceptive and antistress activities were less frequently studied. CONCLUSIONS: Sideritis species should be considered promising therapeutic agents in the treatment of upper respiratory tract and ulcer/inflammatory diseases.

Isoquinoline alkaloids isolated from Glaucium corniculatum var. corniculatum and Glaucium grandiflorum subsp. refractum var. torquatum with bioactivity studies.

CONTEXT: The genus Glaucium Mill., one of the important Papaveraceae family plants, is rich in isoquinoline alkaloids and distributed worldwide. OBJECTIVE: Isolation and identification of bioactive alkaloids from Glaucium grandiflorum Boiss. & Huet. subsp. refractum (Nabelek) Mory var. torquatum (Cullen) Mory and G. corniculatum (L.) Rudolph var. corniculatum (Aslan 2012), and investigation of their antioxidant and anticholinesterase activities. MATERIALS AND METHODS: The aerial parts of each plant were dried, powdered, and percolated with methanol, then each extract was fractionated between 50% aqueous acetic acid and petroleum. Their aqueous acidic layer was adjusted to pH 7-8 with NH4OH and extracted with chloroform, the extract was subjected to CC separation and isolation. Structures of the isolated alkaloids were elucidated by 1D and 2D-NMR and mass spectral analyses. The alkaloid extracts and their pure alkaloids were tested for anti-cholinesterase (AChE and BuChE) and antioxidant (ABTS, CUPRAC, ß-carotene linoleic acid tests) activities in vitro. RESULTS: Methanol extracts of Glaucium grandiflorum subsp. refractum var. torquatum and G. corniculatum var. corniculatum afforded a novel compound glauciumoline and seven known isoquinoline alkaloids three of which have an aporphine-type and the other five have a protopine-type skeleton. Among them, trans-protopinium (7) and cis-protopinium (8) were isolated from a Glaucium species for the first time. Tertiary amine extracts (TAEs) of both plants showed very strong acetylcholinesterase inhibitory activity. The TAE of the plants also showed strong antioxidant activity while the isolated alkaloids showed no meaningful activity in the anticholinesterase and antioxidant tests. DISCUSSION AND CONCLUSIONS: Glaucium species are considered promising therapeutic agents in the treatment of Alzheimer's disease.

Phytochemical analysis and molecular docking studies of two endemic varieties of Salvia sericeotomentosa.

The use of medicinal plants for treating various diseases dates back thousands of years and has been a part of many cultures around the world. Various parts of plants, including roots, leaves, and flowers, and their extracts have been used to develop remedies to cure different ailments like fever, pain, inflammation, infections, among others. In this research, the aerial parts of both Salvia varieties were extracted with ethanol and water to obtain infusion and decoction, separately. S. sericeotomentosa var. hatayica Celep & Dogan (SH) and Salvia sericeotomentosa Rech. f. var. sericeotomentosa (ST) plants were chemically analyzed for polar compounds using LC-HRMS for the first time. All SH and ST extracts were found to be very rich in rosmarinic acid, salvianolic acid B, hispidulin-7-O-glucoside, and caffeic acid. The study also investigated the antiinflammatory and carbonic anhydrase inhibition properties of the most abundant secondary metabolites extracted from SH and ST. In silico studies were conducted for the first time to explore the effects of these metabolites on TNF-α, iNOS, and human carbonic anhydrase isoenzymes (hCAI and hCAII). Salvianolic acid B should be considered a strong antiinflammatory agent and a carbonic anhydrase I and II inhibitors due to low binding energy scores with the tested enzymes (TNF-α: -12.391 kcal/mol), (iNOS: -7.547 kcal/mol), (hCAI: -7.877 kcal/mol), and (hCAII: -4.312 kcal/mol).

Comparing healing effect against ulcerative colitis and toxicological effects of Rosmarinus officinalis: A comprehensive in vivo study of an edible plant in rats.

Ulcerative colitis (UC) is a chronic and inflammatory disorder of the gastrointestinal (GI) tract. UC usually worsens the daily life of the patient and may sometimes become mortal. There is no known remedy discovered against UC, yet. Rosmarinus officinalis consists of many flavonoids, phenolics, and terpenoids possessing various biological activities such as anti-inflammatory. For this reason, in the present study, anti-ulcerative colitis effect of ROME (Rosmarinus officinalis methanol extract) was investigated comprehensively by histopathological studies, a number of in vivo anti-inflammatory activities and several in vivo antioxidant activities, in addition to in vitro antioxidant activities and biochemical analyses. In addition, the toxic effects of ROME were examined. The results showed that ROME provided a significant healing effect against ulcerative colitis in rats. Both in vitro and in vivo assay results correlated with histopathological examinations. ROME exhibited minimal toxic alterations. When the results of rosemary are compared with the results of sulfasalazine, it can be suggested that instead of synthetic drugs with side effects, natural sources can be used for the treatment of various diseases. Although some activities of rosemary have been investigated in vitro in the previous studies, this is the first study revealing anti-ulcerative colitis effect of rosemary through histopathological studies, in vivo and in vitro assays as well as biochemical analyses overall. PRACTICAL APPLICATIONS: The results revealed and proved that ROME provided a significant healing effect against ulcerative colitis in rats. When the results of rosemary are compared with the results of sulfasalazine, a commercially available drug on the market, it can be suggested that instead of synthetic drugs with side effects, natural sources can be used for the treatment of various inflammatory diseases such as UC disease. In addition, ROME possesses limited toxic alterations, but not much more than the commercial drug. As a future perspective, lethal and therapeutic doses can be examined and determined. Thus, human studies can be started through this comprehensive in vivo study on rosemary which is commonly used as an edible plant and spice all over the world.

Investigation of cytotoxic and apoptotic effects of 63 compounds obtained from Salvia species: Promising anticancer agents.

Since ancient time, Salvia L. species have been commonly used to treat colds, bronchitis, tuberculosis, heart diseases, and menstrual and digestive disorders in traditional medicine all around the world. They have been also used as tea and spice. Studies indicated that diterpenes and triterpenes isolated from Salvia species possess various pharmacological and biological effects such as anti-inflammatory, antiviral, cytotoxic, antioxidant, and hepatotoxic activities. Flavones were also shown to have antimicrobial, antioxidant, and cytotoxic potentials. Salvia extracts also exhibit anti-Alzheimer, antiseptic, cardiovascular, antihypertensive, and antituberculous effects. To investigate the effects of 63 secondary metabolites from Salvia species on cell viability and apoptosis, Salvia secondary metabolites including 25 phenolics, 4 fatty acids, 19 abietane diterpenoids, 12 triterpenoids, and three steroids were examined on healthy cell line (PDF), breast cancer (MCF-7), and colon cancer (HT-29) cell lines using MTT method. In addition, the effects of rosmarinic acid, 6,7-dehydroroyleanone, acetyl royleanone, ferruginol, carnosic acid, carnosol, cryptotanshinone, ß-sitosterol, and ursolic acid on pro-apoptotic Bax and antiapoptotic Bcl-2 protein expression levels were investigated by Western Blot method. PRACTICAL APPLICATIONS: Phenolic compounds (apigenin, chrysin, and luteolin) and diterpenes (especially dihydrotanshinone I, carnosic acid, and carnosol), and almost all of the triterpenes exhibited high toxic effects on healthy cell line. Cytotoxic effects of cryptotanshinone, 12-hydroxy abieta-1,3,5(10),8,11,13-hexaene, 12-demethylmulticauline, 6,7-dehydroroyleanone, acetyl royleanone, ferruginol, ursolic acid, and 3-acetyl lupeol were relatively higher than their toxic effects. Acetyl royleanone, 6,7-dehydroroyleanone, carnosic acid, and cryptotanshinone were found to have anticancer potential based on their modulating effects on the expression levels of Bax and Bcl-2 proteins which play important roles in the regulation of apoptosis. The results of the present study showed that acetyl royleanone, cryptotanshinone, 6,7-dehydroroyleanone, carnosic acid, and cryptotanshinone have potential to be used in the pharmaceutical industry.

Identification of natural compounds of Jurinea species by LC-HRMS and GC-FID and their bioactivities.

The Jurinea Cass. is one of the most important genera within Asteraceae and it comprises about 250 species in total. This genus is known for its numerous biological activities such as antioxidant, antimicrobial, antilipid peroxidation, anticholinesterase, antileishmanial activities. The aim of this study was to determine chemical composition and biological activities of ethanol and n-hexane extracts of three different Jurinea species. For this purpose, different parts of J. mollis, J. cadmea and J. pontica were extracted and totally six n-hexane and six ethanol extracts were obtained. Fatty acid content of n-hexane extracts was determined by GC-FID whereas phenolic and flavonoid content of ethanol extracts by LC-HRMS. Palmitic acid (16:0) was detected as the most abundant fatty acid in all n-hexane extracts with the rates ranging from 42.16%-55.08%, except flowers of J. mollis (JMF) and J. cadmea (JCF). LC-HRMS analysis showed the rutin content of all extracts was higher than other flavonoids, except of J. cadmea flowers, whereas apigenin-7-glucoside was found the most abundant in JCF. Cytotoxic effects of the extracts on HeLa and HEK-293 cells were determined by MTT method, and antioxidant activities were evaluated by DPPH and CUPRAC assays. Ethanol extract of J. mollis flowers significantly inhibited cancerous HeLa cells, with the IC50 value of 9.683 µg/mL while it was more less toxic on healthy HEK-293 cells. Ethanol extracts of J. mollis flowers and J. mollis steams-leaves (JMSL) showed the highest antioxidant activity by a DPPH inhibition % of 45.516 ± 2.497 and 56.671 ± 1.496, respectively. JMF and JMSL have also the highest CUPRAC values (0.880 ± 0.067 and 1.085 ± 0.152 mmol TR/g DWE, respectively). Total flavonoid content was determined using aluminum chloride colorimetric assay while total tannin and phenolic content by Folin Chiocalteu's reagent. Results showed that JMSL has the highest total phenolic (108.359 ± 6.241 mg GAE/ G DWE) and flavonoid (32.080 ± 4.385 mg QE/ g DWE) contents whereas JMF has the highest tannin content (121.333 ± 17.889 mg TAE/ g DWE). In the light of these results, various parts of Jurinea species may be regarded as alternative sources for cytotoxic and/or antioxidant flavonoids, phenolics and unsaturated fatty acids that can arouse the interest of pharmaceutical, food and cosmetic industries.

Triterpenoids and steroids isolated from Anatolian Capparis ovata and their activity on the expression of inflammatory cytokines.

CONTEXT: Capparis L. (Capparaceae) is grown worldwide. Caper has been used in traditional medicine to treat various diseases including rheumatism, kidney, liver, stomach, as well as headache and toothache. OBJECTIVE: To isolate and elucidate of the secondary metabolites of the C. ovata extracts which are responsible for their anti-inflammatory activities. MATERIALS AND METHODS: Buds, fruits, flowers, leaves and stems of C. ovata Desf. was dried, cut to pieces, then ground separately. From their dichloromethane/hexane (1:1) extracts, eight compounds were isolated and their structures were elucidated by NMR, mass spectroscopic techniques. The effects of compounds on the expression of inflammatory cytokines in SH-SY5Y cell lines were examined by qRT-PCR ranging from 4 to 96 µM. Cell viability was expressed as a percentage of the control, untreated cells. RESULTS: This is a first report on isolation of triterpenoids and steroids from C. ovata with anti-inflammatory activity. One new triterpenoid ester olean-12-en-3ß,28-diol, 3ß-pentacosanoate (1) and two new natural steroids 5α,6α-epoxycholestan-3ß-ol (5) and 5ß,6ß-epoxycholestan-3ß-ol (6) were elucidated besides known compounds; oleanolic acid (2), ursolic acid (3), ß-sitosterol (4), stigmast-5,22-dien-3ß-myristate (7) and bismethyl-octylphthalate (8). mRNA expression levels as EC10 of all the tested seven genes were decreased, particularly CXCL9 (19.36-fold), CXCL10 (8.14-fold), and TNF (18.69) by the treatment of 26 µM of compound 1 on SH-SY5Y cells. DISCUSSION AND CONCLUSIONS: Triterpenoids and steroids isolated from C. ovata were found to be moderate-strong anti-inflammatory compounds. Particularly, compounds 1 and 3 were found to be promising therapeutic agents in the treatment of inflammatory and autoimmune diseases.

Composition of the essential oil of Satureja metastasiantha: a new species for the flora of Turkey.

The aerial parts of Satureja metastasiantha were hydrodistilled for 3 h using a Clevenger-type apparatus. The essential oils were analyzed by gas chromatography/flame ionization detector and gas chromatography/mass spectrometry, simultaneously, the main compounds of which were characterized as p-cymene (22.3%), thymol (21.0%), carvacrol (18.4%), and γ-terpinene (12.1%). Antioxidant capacity, acetylcholinesterase and butyrylcholinesterase inhibition effects, and antimicrobial and antifungal properties of the species were evaluated. The anticholinesterase activity of the essential oil of S. metastasiantha was observed with 30% inhibition at 200 µg/mL. The essential oil of the species showed activity against Staphylococcus aureus with 128 µg/mL minimum inhibitory concentration value.

Anticholinesterase and Antioxidant Activities of Natural Abietane Diterpenoids with Molecular Docking Studies.

BACKGROUND: Alzheimer's Disease (AD) is one of the most prevalent causes of dementia in the world, and no drugs available that can provide a complete cure. Cholinergic neurons of the cerebral cortex of AD patients are lost due to increased activity of cholinesterase enzymes. OBJECTIVE: Acetylcholinesterase (AChE) and Butyrylcholinesterase (BuChE) are the two major classes of cholinesterases in the mammalian brain. The involvement of oxidative stress in the progression of AD is known. Thus, the objective of this study is to determine strong ChE inhibitors with anti-oxidant activity. METHODS: In this study, 41 abietane diterpenoids have been assayed for antioxidant and anticholinesterase (both for AChE and BuChE) properties in vitro, which were previously isolated from Salvia species, and structurally determined by spectroscopic methods, particularly intensive 1D- and 2DNMR and mass experiments. Molecular modeling studies were performed to rationalize the in vitro ChE inhibitory activity of several abietane diterpenoids compared with galantamine. RESULTS: Thirteen out of the tested 41 abietane diterpenoids exhibited at least 50% inhibition on either AChE or BuChE. The strongest inhibitory activity was obtained for Bractealine against BuChE (3.43 µM) and AChE (33.21 µM) while the most selective ligand was found to be Hypargenin E against BuChE enzyme (6.93 µM). A full correlation was not found between anticholinesterase and antioxidant activities. The results obtained from molecular modelling studies of Hypargenin E and Bractealine on AChE and BuChE were found to be in accordance with the in vitro anti-cholinesterase activity tests. CONCLUSION: Abietane diterpenoids are promising molecules for the treatment of mild-moderate AD.

Inhibition of Amyloid ß Aggregation Using Optimized Nano-Encapsulated Formulations of Plant Extracts with High Metal Chelator Activities.

BACKGROUND: The role of Fe+2, Cu+2 and Zn+2 in facilitating aggregation of Amyloid ß (Aß) and consequently, the progression of Alzheimer's disease (AD) is well established. OBJECTIVE: Development of non-toxic metal chelators is an emerging era in the treatment of AD, in which complete success has not been fully achieved. The purpose of this study was to determine plant extracts with high metal chelator and to encapsulate them in nano-micellar systems with the ability to pass through the Blood Brain Barrier (BBB). METHODS: Extracts of 36 different Anatolian plants were prepared, total phenolic and flavonoid contents were determined, and the extracts with high content were examined for their Fe+2, Cu+2 and Zn+2 chelating activities. Apolipoprotein E4 (Apo E) decorated nano-formulations of active extracts were prepared using Poly (Lactide-co-Glycolide) (PLGA) (final product ApoEPLGA) to provide BBB penetrating property. RESULTS: Verbascum flavidum aqueous extract was found as the most active sample, incubation of which, with Aß before and after metal-induced aggregation, resulted in successful inhibition of aggregate formation, while re-solubilization of pre-formed aggregates was not effectively achieved. The same results were obtained using ApoEPLGA. CONCLUSION: An optimized metal chelator nano-formulation with BBB penetrating ability was prepared and presented for further in-vivo studies.

Bioassay-guided isolation, identification of compounds from Origanum rotundifolium and investigation of their antiproliferative and antioxidant activities.

CONTEXT: Origanum (Lamiaceae) has been used in food and pharmaceutical industries. OBJECTIVE: Isolation and identification of bioactive compounds from Origanum rotundifolium Boiss. and investigation of their antiproliferative and antioxidant activities. MATERIALS AND METHODS: The aerial part of O. rotundifolium was dried and powdered (1.0 kg ±2.0 g) then extracted with hexane, ethyl acetate, methanol and water. Solvent (3 × 1 L) was used for each extraction for a week at room temperature. The aqueous extract was partitioned with ethyl acetate (3 × 1 L) to yield the water/EtOAc extract subjected to chromatography to isolate the active compounds. The structures of isolated compounds were elucidated by 1 D, 2 D NMR and LC-TOF/MS. RESULTS: Apigenin (1), ferulic acid (2), vitexin (3), caprolactam (4), rosmarinic acid (5), and globoidnan A (6) were isolated and identified. Globoidnan A (6), vitexin (3), and rosmarinic acid (5) revealed the excellent DPPH• scavenging effect with IC50 values of 22.4, 31.4, 47.2 µM, respectively. Vitexin (3) (IC50 3.6), globoidnan A (6) (IC50 4.6), apigenin (1) (IC50 8.9) and ferulic acid (2) exhibited more ABTS•+ activity than standard Trolox (IC50 13.8 µg/mL). Vitexin (3) revealed the most antiproliferative activity against HeLa, HT29, C6 and Vero cells lines with IC50 values of 35.6, 32.5, 41.6, 46.7 (µM), respectively. DISCUSSION AND CONCLUSION: Globoidnan A (6) has the most antioxidant effects on all assays. This has to do with the chemical structure of the compound bearing the acidic protons. Vitexin (3) could be a promising anticancer agent.

Capparis ovata treatment suppresses inflammatory cytokine expression and ameliorates experimental allergic encephalomyelitis model of multiple sclerosis in C57BL/6 mice.

Since ancient times, Capparis species have been widely used in traditional medicine to treat various diseases. Our recent investigations have suggested Capparis ovata's potential anti-neuroinflammatory application for the treatment of multiple sclerosis (MS). The present study was designed to precisely determine the underlying mechanism of its anti-neuroinflammatory effect in a mouse model of MS. C. ovata water extract (COWE) was prepared using the plant's fruit, buds, and flower parts (Turkish Patent Institute, PT 2012/04,093). We immunized female C57BL/6J mice with MOG35-55/CFA. COWE was administered at a daily dose of 500mg/kg by oral gavage either from the day of immunization (T1) or at disease onset (T2) for 21days. Gene expression analysis was performed using a Mouse Multiple Sclerosis RT² Profiler PCR Array, and further determinations and validations of the identified genes were performed using qPCR. Whole-genome transcriptome profiling was analyzed using Agilent SurePrint G3 Mouse GE 8X60K microarrays. Immunohistochemical staining was applied to brain sections of the control and treated mice to examine the degree of degeneration. COWE was further fractionated and analyzed phytochemically using the Zivak Tandem Gold Triple Quadrupole LC/MS-MS system. COWE remarkably suppressed the development of EAE in T1, and the disease activity was completely inhibited. In the T2 group, the maximal score was significantly reduced compared with that of the parallel EAE group. The COWE suppression of EAE was associated with a significantly decreased expression of genes that are important in inflammatory signaling, such as TNFα, IL6, NF-κB, CCL5, CXCL9, and CXCK10. On the other hand, the expression of genes involved in myelination/remyelination was significantly increased. Immunohistochemical analysis further supported these effects, showing that the number of infiltrating immune cells was decreased in the brains of COWE-treated animals. In addition, differential expression profiling of the transcriptome revealed that COWE treatment caused the down regulation of a group of genes involved in the immune response, inflammatory response, antigen processing and presentation, B-cell-mediated immunity and innate immune response. Collectively, these results suggest anti-neuroinflammatory mechanisms by which COWE treatment delayed and suppressed the development of EAE and ameliorated the disease in mice with persistent clinical signs.

Chemical profile and biological activities of Veronica thymoides subsp. pseudocinerea.

CONTEXT: In Turkey, Veronica species (Plantaginaceae) have been used as a diuretic and for wound healing in traditional medicine. OBJECTIVE: To examine the fatty acid and essential oil profiles, the antioxidant, anticholinesterase, antimicrobial, and DNA damage effects of Veronica thymoides P.H. Davis subsp. pseudocinerea M.A. Fischer as a potential source of natural active compounds. MATERIALS AND METHODS: GC/MS was used to analyze essential oil and fatty acid obtained from whole plant. The antioxidant activity was evaluated by the ß-carotene-linoleic acid test system, DPPH-free and ABTS cation radicals scavenging, and cupric reducing antioxidant capacity assays. The anticholinesterase and antimicrobial activities were determined by Ellman and broth macrodillution methods, respectively. The effect of the methanol extract on DNA cleavage was investigated. RESULTS: Hexatriacontene (21.0%) was found to be the main constituent in essential oil, and linoleic acid (25.2%) and palmitic acid (20.6%) in fatty acid. Methanol extract demonstrated the best IC50 values in lipid peroxidation (49.81 ± 0.31 µg/ml) and DPPH-free radical scavenging activity (15.32 ± 0.17 µg/ml). Methanol and water extracts possessed strong ABTS cation radical scavenging activity with IC50 values 9.15 ± 0.28 and 8.90 ± 0.1 µg/ml, respectively. The acetone extract exhibited moderate butyrylcholinesterase inhibitory activity. The highest antimicrobial activity was determined in methanol extract against Escherichia coli with 31.25 µg/ml MIC value. Inhibition of methanol extract on plasmid DNA cleavage by OH radicals was found to be 93.32% at 500 µg/ml. CONCLUSION: The methanol extract having strong antioxidant and DNA damage effects could be investigated phytochemically to find natural active compounds.

Antioxidant and tyrosinase inhibitory activities of flavonoids from Trifolium nigrescens Subsp. petrisavi.

Trifolium nigrescens was researched for its chemical constituents for the first time. Bioassay-guided isolation of the EtOAc extract from the leaves of T. nigrescens resulted in the purification of a new biflavone, 4''',5,5″,7,7″-pentahydroxy-3',3'''-dimethoxy-3-O-ß-d-glucosyl-3″,4'-O-biflavone (1) along with eleven known compounds consisting of three phenolics (2-4), and eight flavonoid glycosides (5-12). Their structures were determined by extensive 1D and 2D NMR, and MS data analyses. The isolated compounds were evaluated for their antioxidant activity and inhibitory activity on mushroom tyrosinase. Highly potent inhibitions were found by compounds 7 (IC50 = 0.38 mM), 8 (IC50 = 0.19 mM), and 12 (IC50 = 0.26 mM) when compared with standard tyrosinase inhibitors kojic acid (IC50 = 0.67 mM) and l-mimosine (IC50 = 0.64 mM). The antioxidative effect of the isolated compounds and the extracts were determined by using ß-carotene-linoleic acid, DPPH(•) scavenging, ABTS(+•) scavenging, superoxide scavenging, and CUPRAC assays. The experimental findings indicated that all the compounds demonstrated activity in all antioxidant activity tests employed except for the compounds 2-6. Compounds 2-6 showed moderate activity only in ABTS(+•) scavenging assay. The new compound 1 exhibited better activity than standard α-tocopherol in DPPH(•) scavenging, and ABTS(+•) scavenging assays. The results show that T. nigrescens can be regarded as a potential source of antioxidant compounds and tyrosinase inhibitors of significance in both the pharmaceutical and food industries.

Bioactive constituents of Salvia chrysophylla Stapf.

The dichloromethane extract of the aerial parts of Salvia chrysophylla Stapf (Lamiaceae), which is an endemic species to south-western Anatolia, was studied for non-volatile secondary metabolites for the first time in this study. Structures of the isolated compounds were elucidated as sclareol, ß-sitosterol, salvigenin, oleanolic acid and ursolic acid. The lipid peroxidation inhibitory activity and the DPPH free radical scavenging activity of the pure isolates were investigated to establish their antioxidant potential. Their anticholinesterase activity was carried out by the Ellman assay against both enzymes, acetylcholinesterase (AChE) and butyrylcholinesterase, and diterpene sclareol exhibited fairly good activity against both the enzymes while the two triterpenoids oleanolic and ursolic acids exhibited selective activity against AChE.

A novel isopimarane diterpenoid with acetylcholinesterase inhibitory activity from Nepeta sorgerae, an endemic species to the Nemrut Mountain.

From the dichloromethane extract of Nepeta sorgerae, the isolation and structure elucidation are now reported of a new isopimarane diterpenoid, named sorgerolone, and two known triterpenoids, oleanolic acid and ursolic acid. Antioxidant activity of the extracts and the isolated terpenoids was determined by the DPPH free radical scavenging and lipid peroxidation inhibition (beta-carotene bleaching) methods. Anticholinesterase activity of the extracts and isolates was investigated by Ellman's method against AChE and BChE enzymes. Although the antioxidant activity results were low, the AChE enzyme inhibition of the extracts and terpenoids was very promising.

Indole alkaloids from Vinca major and V. minor growing in Turkey.

A new indole alkaloid, 11-hydroxypolyneuridine, was isolated from Vinca major subsp. major L. and the known indole alkaloids vallesiachotamine and isovallesiachotamine from Vinca minor L. This is the first report on the alkaloids of both Vinca species growing in Turkey; vallesiachotamine and isovallesiachotamine were isolated from a Vinca species for the first time. V. minor may be considered as a new source for these two alkaloids due to their occurrence in high amount in the aerial parts of the plant. The alkaloid extracts of the two Vinca species were found to have high lipid peroxidation inhibitory and DPPH radical scavenging activities. Anticholinesterase activity of the extracts was also very strong.

Evaluation of fruit extracts of six Turkish Juniperus species for their antioxidant, anticholinesterase and antimicrobial activities.

BACKGROUND: Juniperus L. (Cupressaceae) species are mostly spread out in the Northern Hemisphere of the world, and some of them are used as folkloric medicines. The fruits of some species are eaten. Since oxidative stress is one of the reasons for neurodegeneration and is associated with the Alzheimer's disease (AD), the extracts prepared from the fruits of six Juniperus species were screened for their antioxidant activity. Therefore, the extracts were also evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are chief enzymes in the pathogenesis of AD. In addition, antimicrobial activity was also evaluated. RESULTS: In the ß-carotene-linoleic acid assay, acetone extracts of J. oxycedrus subsp. oxycedrus, J. sabina and J. excelsa, and methanol extracts of J. phoenicea and J. sabina, effectively inhibited oxidation of linoleic acid. The hexane extracts of J. oxycedrus subsp. oxycedrus, J. foetidissima and J. phoenicea showed remarkable inhibitory effect against AChE and BChE. CONCLUSION: Because of their high antioxidant activity, J. excelsa, J. oxycedrus subsp. oxycedrus, J. sabina and J. phoenicia might be used in the food industry as preservative agents or extension of the shelf-life of raw and processed foods. Since the hexane extracts of J. oxycedrus subsp. oxycedrus and J. foetidissima demonstrated significant anticholinesterase activity they should be considered as a potential source for anticholinesterase agents.

Chemical composition of the essential oil and hexane extract of Salvia chionantha and their antioxidant and anticholinesterase activities.

The essential oil and methyl ester of hexane extract of Salvia chionantha Boiss. were analysed by GC and GC-MS. Totally, 54 components were detected in the essential oil and all of them were fully determined. Germacrene D (25.03%), ß-caryophyllene (8.71%), spathulenol (5.86%) and α-humulene (4.82%) were identified as the major compounds. In the methylated hexane extract, 3-hydroxy hexadecanoic acid (39.39%), 3-hydroxy tetradecanoic acid (12.66%) and palmitic acid (12.02%) were the major fatty acids elucidated. The antioxidant activity of the essential oil and the hexane extract was determined by using four complementary test systems; namely, ß-carotene-linoleic acid, DPPH() scavenging, ABTS(+)* scavenging, and CUPRAC assays. In ß-carotene-linoleic acid assay, the extract showed 81.2±0.1% lipid peroxidation inhibition at 0.8 mg/mL concentration, while in ABTS(+)* assay the essential oil exhibited 77.4±0.5% inhibition at same concentration. Since, acetylcholinesterase and butyrylcholinesterase enzymes are taking place in pathogenesis of Alzheimer's disease, in vitro anticholinesterase activity of the essential oil and the extract was also studied spectrophotometrically. At 0.5mg/mL concentration, the essential oil showed moderate acetylcholinesterase (56.7±1.9%) and butyrylcholinesterase (41.7±2.9%) inhibitory activity, while the extract was only exhibited activity (63.1±0.8%) against butyrylcholinesterase enzyme. Hence, the essential oil may be useful as a moderate anticholinesterase agent, particularly against acetylcholinesterase.

Isolation and analysis of bioactive diterpenoids in Salvia species (Salvia chionantha and Salvia kronenburgiii) by micellar electrokinetic capillary chromatography.

In the present work, we isolated two bioactive diterpenoids, horminone and 7-O-acetylhorminone and developed a micellar electrokinetic chromatography (MEKC) method for the simultaneous quantitative analysis of them in Turkish Salvia species. The optimal separation electrolyte was 50 mmol/L SDS and 25% methanol at pH 11.5. The limits of detection (S/N=3) were 3.269 and 4.518 microg/mL for horminone and 7-O-acetylhorminone, respectively. The method has been applied successfully to analyze these two components in Salvia chionantha and Salvia kronenburgii acetone extracts.