UV/VIS spectral properties of novel natural products from Turkish lichens

UV/VIS spectral characteristics of three new biologically active natural products, isolated from Turkish lichens, have been investigated in solvents of various polarity and proton donating ability. The effect of the solvent on spectral characteristics has been estimated. Quantum chemical calculations with the optimization of molecular geometry were done with the full-valent semiempirical methods AM1 and PM3 for conformational analysis and in order to discuss the charge distributions and dipole moments in the ground and in the excited states

Enantioselective synthesis of 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles from 2-iminochromenes

A series of medicinally important 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles were synthesized using enantioselective conjugate addition of nitromethane to 2-iminochromenes. The reactions were performed using L8-Cu (II) catalytic system and moderate to good enantioselectivities (62-88%) and yields (66-96%) were obtained

Isolation and structural determination of some natural products from ononis natrix subsp. natrix

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.ABSTRACT KOZ, Ömer Master of Science Thesis, Chemistry Department Supervisor: Assoc. Prof. Dr. Süheyla KIRMIZIGÜL August 2000, 56 Pages Botanically examined, dried and grinded plant material of Ononis natrix subsp. natrix was studied by means of chemical properties. After the isolation and purification experiments, a Nortriterpene glycoside, a Pterocarpan glycoside and a Substitue Aromatic Lactone was obtained. The structural determination of pure compounds was carried out using different chemical, choromatographic and spectroscopic (IR, UV, NMR, Mass, and Fluorescence Emission) methods. Keywords: Nortriterpene, Pterocarpan, Aromatic Lactone, Glycoside.m ÖZET KOZ, Ömer Yüksek Lisans Tezi, Kimya Bölümü Tez Yöneticisi:Doç. Dr. Süheyla KIRMIZIGÜL Ağustos 2000, 56 Sayfa Botanik olarak belirlenen Ononis natrix subsp. natrix bitkisi, kurutulup öğütüldükten sonra ve kimyasal olarak incelendi. İzolasyon işlemleri sonrası bir Nortriterpen Glikozit, bir Pterokarpan Glikozit ve bir Substitue Aromatik Lakton elde edildi. Saf olarak elde edilen bu bileşiklerin yapılarının belirlenmesinde çeşitli kimyasal, kromatografik ve spektroskopik (İR, UV, NMR, Kütle ve Fluoresans Emisyon) yöntemler kullanıldı

Isolation, structural determination and biological activities of some natural products from Campanula lyrata subsp. lyrata (campanulaceae) and Anchusa undulata subsp. hybrida (boraginaceae)

Anchusa undulata subsp. hybrida ve Campanula lyrata subsp. lyrata (Campanulaceae) (endemik) bitkileri kimyasal (hidroliz) ve kromatografik (TLC, Prep. TLC, CC, VLC, MPLC, adsorban olarak SilicaGel, RP-SilicaGel, Sephadex) yöntemler kullanılarak incelendi. Ana ekstrelerin antimikrobiyal aktiviteleri, farklı mikroorganizmalara karsı Disk-diffuzyon metodu ile incelendi. İzolasyon ve saflandırma islemlerinden sonra A. undulata subsp. hybridaʼdan 3-O-(b-D-glucopyranosyl)-29-O-(b-D-glucopyranosyl)- 2a,3b,23-trihydroxyolean-12-en-28-oic acid (Undulatoside (9)) bilesigi yeni olmak üzere dokuz bilesigin, Rutin (1), Anchusoside-3 (2), Anchusoside-8 (3), Anchusoside-9 (4), Anchusoside-4 (5), Anchusoside- 5 (6), Anchusoside-11 (7) Viscoside A (8) ve C. lyrata subsp. lyrataʼdan dört bilesigin, Demethyl syringin (10), Kaempferol-3-O-b-Dglucuronopyranoside (11), Quercetin-3-O-b-D-glucuronopyranoside (12) ve 3-caffeoylquinic acid (13) olmak üzere, 12ʼsi glikozit toplam 13 bilesigin yapıları FTIR, UV-Vis., 1D ve 2D NMR, ve ESIMS teknikleri ile saptandı

L-(+)-tryptophan methyl ester derived polymeric microbeads as an efffiicient heterogeneous catalyst for green synthesis of 2-amino-4-(nitromethyl)-4h-chromene-3-carbonitriles

The cross-linked microbeads with average diameter of 106-300 mu m, [poly(EGDMA-MATrp)], were obtained by copolymerization reaction of N-methacryloyl-L-(+)-tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA) and successfully applied as a heterogeneous catalyst in conjugate addition reaction of nitromethane to substituted 2-iminochromenes in aqueous media. A variety of 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles has been synthesized in good yields. Polymeric microbeads were very durable and reused 5 times without a significant loss of activity. DFT calculations and experimental results revealed the significant role of Tr-Tr interactions as well as hydrogen bonding in the reaction mechanism.Bursa Technical University Scientific Research Fund -- BAP 211N02

Isolation and structure elucidation of novel natural products from Turkish lichens

Three natural products were isolated from three different Turkish lichens. Microbiological investigations were also examined of these lichens. Compound 1 is known as 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid, and is isolated from Pseudevernia furfuracea for the first time. Compounds 2 and 3 are detected as new compounds and called, 3-acetyl-4-amino-2-chloro-1- (4-hydroxy-2-methoxy- 6-methylphenyl carbonyloxy) benzene and 2-(4-methoxyphenyl)-2-(5-oxo-4-phenyl-2,5- dihydro-2-furaniliden) acetic acid; they were isolated from Evernia prunastri and Letharia vulpina, respectively. All these compounds had different skeletons. Their structures were established by chemical methods and spectroscopic techniques using IR, UV, 1D and 2D NMR and EI and (+) FAB-Mass methods

Semi-Purified Saponins of Holothuria poli Associated Antiproliferation in Tumor Cell Lines

The incidence of cancer has exhibited an increasing trend in recent years because of many reasons such as environmental and nutritional factors. There is a great need for the development of new and natural molecules with lower side effects in the therapy of cancer. It was aimed to evaluate the antiproliferative effect of semi-purified triterpene glycosides of Holothuria poli on different human cancer cell lines. The body walls of H. poli as the main sources of saponins were used and the saponin content of the extract was characterized by MALDI-TOF/MS. The antiproliferation activity of the characterized extract was tested on cancer cell lines. The extract showed antiproliferative effect on the studied cancer cell lines. The mass analysis results reveal that Holothurin A is one of the saponins within the extract. The measured IC50 values were found as 31.41 +/- 2.20, 77.45 +/- 0.23, and 34.79 +/- 0.90 mu g mL(-1) for HT-29, UPCI-SCC-131, and T84 cell lines, respectively. H. poli secretes not only specific saponins but also a cocktail of them. Specific versus. cocktails of the saponins and by also applying organic modification must be studied in further research to understand their mechanisms in the antiproliferation studies since this paper reveals promising results