Person: ALİM TORAMAN, GÜLBAHAR ÖZGE
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Publication Open Access Isoquinoline alkaloids isolated from Glaucium corniculatum var. corniculatum and Glaucium grandiflorum subsp. refractum var. torquatum with bioactivity studies(2023-06-01) Kuşman Sayğı T.; Tan N.; Alim Toraman G. Ö.; Gürer Ç.; Tugay O.; Topçu G.; ALİM TORAMAN, GÜLBAHAR ÖZGE; TOPÇU, GÜLAÇTIContext: 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, β-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.Publication Metadata only Novel Chalcone Derivatives of Ursolic Acid as Acetylcholinesterase Inhibitors: Synthesis, Characterization, Biological Activity, ADME prediction, Molecular Docking and Molecular Dynamics Studies(2023-10-01) Şenol H.; Ghaffari-Moghaddam M.; Alim Toraman G. Ö.; Güller U.; ŞENOL, HALIL; ALİM TORAMAN, GÜLBAHAR ÖZGEPublication Open Access Emodin and aloe-emodin, two potential molecules in regulating cell migration of skin cells through the MAP kinase pathway and affecting Caenorhabditis elegans thermotolerance(2023-12-01) GÜNAYDIN AKYILDIZ, AYŞENUR; Yanikoglu R. S.; Gulec M.; ALİM TORAMAN, GÜLBAHAR ÖZGE; Kuran E. D.; Atasoy S.; Olgun A.; Topcu G.; TOPÇU, GÜLAÇTI; ATASOY, SEZEN; GÜNAYDIN AKYILDIZ, AYŞENUR; ALİM TORAMAN, GÜLBAHAR ÖZGE; YANIKOĞLU, RABİA SAREBackground: Emodin and aloe-emodin are two anthraquinones having positive effects in wound healing. However, their mechanism of action of wound healing is not fully understood. The MAP kinase family, which plays an active role in wound healing, is a well-characterized large family of serine/threonine kinases and regulates processes such as proliferation, oncogenesis, differentiation, and inflammation in the cell. The aim of this study is to comparatively elucidate the mechanisms of action of emodin and aloe-emodin, which are potential agents in wound healing. Methods: The mechanism of the effects of emodin and aloe-emodin on cell viability and cell migration was examined using the human skin fibroblast (CCD-1079Sk) cell line. The gene expression levels of the MAP kinases (JNK, P38, ERK) in the skin fibroblast cells along with a molecular docking study analyzing their interaction potential were evaluated. Furthermore, the molecules’ effects on the lifespan of Caenorhabditis elegans were studied. Results: Emodin and aloe-emodin inhibited the ATP content of the cells in a concentration dependent manner and accelerated cell migration at the lower concentrations while inhibiting cell migration in the higher concentration treatment groups. The expressions of JNK and P38 were upregulated at the low concentrations and downregulated at the higher concentrations. The molecular docking studies of the molecules gave high docking scores indicating their interaction potential with JNK and P38. C. elegans lifespan under heat stress was observed longer after 75 µM emodin and was significantly reduced after 150 µM aloe-emodin treatment. Conclusion: Aloe-emodin was found to be more potent on cell viability, cell migration, gene expression levels of the MAP kinases in healthy fibroblastic skin cells, and on the lifespan of C. elegans. This study reveals the functional effects and the biological factors that interact in the wound healing process of emodin and aloe-emodin, and give a possible treatment alternative to shorten the duration of wound care.Publication Metadata only Cytotoxic meroterpenoids from brown alga Stypopodium schimperi (Kützing) Verlaque & Boudouresque with comprehensive molecular docking & dynamics and ADME studies(2024-01-01) Demirkıran Ö.; Erol E.; Şenol H.; Kesdi İ. M.; Alim Toraman G. Ö.; Okudan E. Ş.; Topçu G.; EROL, EBRU; ŞENOL, HALIL; ALİM TORAMAN, GÜLBAHAR ÖZGE; TOPÇU, GÜLAÇTIPublication Metadata only Chemical profile of the Anatolian Sideritis species with bioactivity studies(2023-01-01) Çarıkçı S.; Kılıç T.; Gören A. C.; Dirmenci T.; ALİM TORAMAN G. Ö.; TOPÇU G.; ALİM TORAMAN, GÜLBAHAR ÖZGE; TOPÇU, GÜLAÇTIContext: 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.