Ali A. Dönmez

Evaluation of Biological Activity of Turkish Plants. Rapid Screening for the Antimicrobial, Antioxidant, and Acetylcholinesterase Inhibitory Potential by TLC Bioautographic Methods

Using thin-layer chromatography (TLC) bioautography, a total of 58 extracts from various organs (aerial parts, leaves, flowers, fruits, roots) of 16 Turkish plants were tested for their antibacterial, antifungal, acetylcholinesterase inhibitory, antioxidant, and radical scavenging activities. The hexane, CHCl3/CH2Cl2, water, and total MeOH extracts were used. No activity was observed against two Gram-negative bacteria (Escherichia coli and Pseudomonas aureginosa) and the yeast Candida albicans. However, 23 plant extracts, mostly the CHCl3/CH2Cl2 and H2O-solubles, inhibited the growth of all five Gram-positive bacteria tested, Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis. Of the active extracts, the CHCl3-soluble of the roots of Putoria calabrica (L. fil) DC (Rubiaceae) displayed the highest antibacterial potential. The majority of the CHCl3/CH2Cl2 crude extracts also appeared to inhibit acetylcholinesterase on TLC plates at 100 µg/spot concentration. Particularly active samples were the middle polarity extracts (CHCl3/CH2Cl2) of the leaves of Rhododendron smirnovii Trautv., R. ponticum L., and R. ungernii Trautv. (Ericaceae). β-Carotene, β-carotene/linoleic acid mixture, and 2,2-diphenyl-l-pieryhydrazyl (DPPH) solutions sprayed onto TLC plates were used for detecting antioxidant and radical scavenging properties of the crude extracts. Antioxidant and radical scavenging activities were found to be predominant in highly polar extracts. The water-solubles of all Rhododendron (Ericaceae) and Phlomis (Lamiaceae) species presented the most significant activity.

Analysis of the volatile components of five Turkish Rhododendron species by headspace solid-phase microextraction and GC-MS (HS-SPME-GC-MS).

Abstract Volatile constituents of various solvent extracts (n-hexane, CH2Cl2, H2O) of 15 different organs (leaves, flowers, fruits) of five Rhododendron species (Ericaceae) growing in Turkey were trapped with headspace solid-phase microextraction (HS-SPME) technique and analyzed by GC-MS. A total of 200 compounds were detected and identified from organic extracts, while the water extracts contained only traces of few volatiles. The CH2Cl2 extract of the R. luteum flowers was found to exhibit the most diverse composition: 34 compounds were identified, with benzyl alcohol (16.6%), limonene (14.6%) and p-cymene (8.4%) being the major compounds. The CH2Cl2-solubles of R. x sochadzeae leaves contained only phenyl ethyl alcohol. This study indicated appreciable intra-specific variations in volatile compositions within the genus. Different anatomical parts also showed altered volatile profiles. This is the first application of HS-SPME-GC-MS on the volatiles of Rhododendron species.

Effects of Salvia. Essential Oils on the Chorioallantoic Membrane (CAM) Assay

Abstract The aerial parts of Salvia hedgeana. Dönmez, Salvia huberi. Hedge, Salvia pisidica. Boiss. & Heldr. ex. Bentham. were subjected to hydrodistillation. The obtained essential oils were analyzed both by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The analyses showed that S. hedgeana. essential oil consisted of β-pinene (30.0%) as a major component, in addition to 65 identified components, representing 89.9% of the total essential oil. The major component of S. huberi. was identified as 1,8-cineole (20.4%), and 76 further components were characterized representing 87.6%. S. pisidica. essential oil revealed the occurrence of camphor (21.7%) as the main constituent among another 59 identified components of 76.8% of the total. Furthermore, the biological properties of the analyzed essential oils were tested using the in vivo. method on the chorioallantoic membrane (CAM) in order to examine the anti-inflammatory and anti-angiogenic activity as well as possible irritant or toxic side effects. All essential oils tested at a concentration of 100 µg/pellet showed no pronounced anti-inflammatory, angiogenic, or membrane-toxic properties.

Secondary metabolites from Phlomis oppositiflora

In addition to rare phenylethanoid triglycosides, myricoside and its dimetylether derivative serratumoside A {3-hydroxy,4-methoxy-β-phenylethoxy-O-β-D-apiofuranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 3)-4-O-feruloyl-β-D-glucopyranoside}, a new phenylethanoid glycoside, myricoside-3′′′′-O-methylether {3,4-dihydroxy-β-phenylethoxy-O-β-D-apiofuranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 3)-4-O-feruloyl-β-D-glucopyranoside} along with a new neolignan glucoside, (7S, 8R)-dehydroconiferyl alcohol-8-5′-dehydroconiferyl aldehyde 4-O-β-D-glucopyranoside were isolated from the aerial parts of Phlomis oppositiflora. The structures of the new compounds were identified by means of spectroscopic (UV, IR, 1D- and 2D-NMR, and LC-ESIMS) methods.

Phenylethanoid Glycosides from Phlomis integrifolia Hub.-Mor.

Abstract Two new phenylethanoid glycosides integrifoliosides A (2) and B (3), along with a known phenylethanoid glycoside alyssonoside (1) and a flavone glucoside chrysoeriol-7-O-β-ᴅ-glucopyranoside (4) were isolated from the aerial parts of Phlomis integrifolia. The structures of the new compounds were identified as 3,4-dihydroxy-β-phenylethoxy-O-β-ᴅ-apiofuranosyl- (1 →4)-α-ʟ-rhamnopyranosyl-(1 →3)-4-O-feruloyl-β-ᴅ-glucopyranoside (2) and 3-hydroxy-4-methoxy-β-phenylethoxy-O-β-ᴅ-apiofuranosyl-(154)-α-ʟ-rhamnopyranosyl-(1→3)-4-O-feruloyl-β-ᴅ-glucopyranoside (3), on the basis of spectroscopic (UV, IR, 1D- and 2D-NMR, and HR-FABMS) methods.

Amanicadol, a pimarane-type diterpene from Phlomis amanica Vierch

Fractionation of the methanol extract of Phlomis amanica resulted in the isolation of a new pimarane type diterpene, amanicadol (1), together with the known glycosides lamiide, verbascoside (= acteoside), syringaresinol-4-O-β -glucoside, liriodendrin, syringin, and a caffeic acid ester, chlorogenic acid. The structure of the new compound was established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. Molecular modeling studies on 1 were conducted and showed that it exhibited low conformational flexibility. Additionally, NMR chemical shifts were calculated for 1 in vacuo, and calculated values were in very close agreement with those found experimentally.

Polygala turcica (Polygalaceae), a new species from E Turkey, and a new identification key to Turkish Polygala

Abstract Dönmez A. A., Uğurlu Aydin Z. & Işık S.: Polygala turcica (Polygalaceae), a new species from E Turkey, and a new identification key to Turkish Polygala. — Willdenowia 45: 429–434. 2015. — Version of record first published online on 16 November 2015 ahead of inclusion in December 2015 issue; ISSN 1868-6397;