Stephen M. MacManus

Bioactivity of two Turkish endemic Centaurea species, and their major constituents

The antioxidant activity, general toxicity and cytotoxicity of the methanol extracts of Centaurea urvillei subs. armata and C. mucronifera have been assessed, respectively, by the DPPH assay, the brine shrimp lethality and the MTT cytotoxicity assays. The reversed-phase HPLC analysis of the methanol extracts afforded two bioactive dibenzylbutyrolactone-type lignans, matairesinoside (1) and arctiin (2). The structures of these lignans were elucidated by comprehensive spectroscopic analyses as well as by the direct comparison of experimental data with respective literature data.

Hydrogen bonding in salicylsalicylic acid (salsalate) crystals.

An X-ray crystallographic study of the drug salsalicylic acid (salsalate) has been performed. Crystal formation of the drug is influenced by both inter- and intra-molecular hydrogen bonding. In addition an OH group in salsalate can occupy alternate ortho positions resulting in two hydrogen bonding motifs within a single crystal.

Extracts of Centaurea bornmuelleri and Centaurea huber-morathii inhibit the growth of colon cancer cells in vitro

SUMMARY Plants from the genus Centaurea (C.) (Family: Asteraceae alt. Compositae), widely distributed inAsia, Europe and North America, have traditionally been used in the treatment of variousailments. As a part of our on-going studies on the plants from the genus C. for theirphytochemistry and biological activities, extracts of the seeds of Turkish endemic C. species, C.bornmuelleri and C. huber-morathii, were tested for their cytotoxicity towards the CaCo2 coloncancer cell line as well as for the toxicity towards the brine shrimps, using the MTT and the brineshrimp lethality assays, respectively. Among the extracts, the MeOH extract of these plantsshowed significant toxicity towards the brine shrimps (LD 50 = 55.2 × 10 -2 and 42.4 10 -2 mg/ml,respectively). The MeOH extract of both C. species also inhibited the growth of CaCo2 coloncancer cells in the MTT assay (IC 50 = 29.9 and 33.0 g/ml, respectively). As the most prominentactivities in both assays were observed with the MeOH extracts, it can be assumed that thecompound(s) responsible for these activities are polar in nature. Key words: Asteraceae; Compositae; Centaurea bornmuelleri; Centaurea huber-morathii; MTT assay;Brine shrimp lethality assay; Colon cancer; CaCo2

5-Chloro-2-hydroxybenzophenone, featuring O-H...O, C-H...O, C-H...π and π-π interactions

Molecules of the title compound, C13H9ClO2, contain an intramolecular O—H⋯O hydrogen bond, and the two aromatic rings are inclined at 57.02 (3)° with respect to one another. The crystal structure is supported by C—H⋯O, C—H⋯π and π–π interactions.

Crystal and molecular structure of 3,5-cycloandrostan-6β-ol-17-one

The crystal and molecular structure of 3,5-cycloandrostan-6β-ol-17-one has been determined by X-ray analysis,13C-NMR,1H-NMR, IR and elemental analyses. The compound was obtained from dehydroepiandrosterone (DHEA) via the 3β-tosyl derivative by refluxing in a butan-2-one/water mixture. The X-ray analysis shows that the planar cyclopropane ring is predominantlyα orientated and the formation of the C(3)-C(5) bond enables the A ring to adopt a distorted boat conformation. Spectroscopic evidence for the presence of the cyclopropane ring and the 6β-hydroxy group are presented.

X-ray crystallographic analysis and NMR study of (Z)-3(2-hydroxyphenyl)-1(4-methoxyphenyl)-3-oxo-prop-1-en-1-ol

The molecular structure of the title compound has been determined by X-ray crystallography. The enol form is present in the solid state and each of the two molecules in the asymmetric unit possesses two intramolecular hydrogen bonds. The delocalization of double bonds results in an almost planar molecule. Evidence to support the enol configuration in solution is presented from an NMR investigation.