In Vitro Studies Demonstrate Antitumor Activity of Vanadium Ions from a CaO-P2O5-CaF2:V2O5 Glass System in Human Cancer Cell Lines A375, A2780, and Caco-2

In this research, we investigated the structural and biological properties of phosphate glasses (PGs) after the addition of V2O5. A xV2O5∙(100 − x)[CaF2∙3P2O5∙CaO] glass system with 0 ≤ x ≤ 16 mol% was synthesized via a conventional melt-quenching technique. Several analysis techniques (dissolution tests, pH, SEM-EDS, FT-IR, and EPR) were used to obtain new experimental data regarding the structural behavior of the system. In vitro tests were conducted to assess the antitumor character of V2O5-doped glass (x = 16 mol%) compared to the matrix (x = 0 mol%) and control (CTRL-) using several tumoral cell lines (A375, A2780, and Caco-2). The characterization of PGs showed an overall dissolution rate of over 90% for all vitreous samples (M and V1−V7) and the high reactivity of this system. EPR revealed a well-resolved hyperfine structure (hfs) typical of vanadyl ions in a C4v symmetry. FT-IR spectra showed the presence of all structural units expected for P2O5, as well as very clear depolymerization of the vitreous network induced by V2O5. The MTT assay indicated that the viability of tumor cells treated with V7-glass extract was reduced to 50% when the highest concentration was used (10 µg/mL) compared to the matrix treatment (which showed no cytotoxic effect at any concentration). Moreover, the matrix treatment (without V2O5) provided an optimal environment for tumor cell attachment and proliferation. In conclusion, the two types of treatment investigated herein were proven to be very different from a statistical point of view (p < 0.01), and the in vitro studies clearly underline the cytotoxic potential of vanadium ions from phosphate glass (V7) as an antitumor agent.

Synthesis and Structural Characterization of CaO-P2O5-CaF:CuO Glasses with Antitumoral Effect on Skin Cancer Cells

Copper is one of the most used therapeutic metallic elements in biomedicine, ranging from antibacterial approaches to developing new complexes in cancer therapy. In the present investigation, we developed a novel xCuO∙(100 − x) [CaF₂∙3P₂O₅∙CaO] glass system with 0 ≤ x ≤ 16 mol% in order to determine the influence of doping on the composition structure of glasses. The samples were characterized by dissolution tests, pH measurements, Fourier-transform infrared spectroscopy (FT-IR), electron paramagnetic resonance (EPR), Scanning Electron Microscopy with energy dispersive spectroscopy (SEM-EDX) and afterward, their antitumor character was assessed. The glasses were mostly soluble in the aqueous medium, their dissolution rate being directly proportional to the increase in pH and the level of doping up to x = 8 mol%. FT-IR spectra of glass samples show the presence of all structural units characteristic to P₂O₅ in different rates and directly depending on the depolymerization process. SEM-EDX results revealed the presence of an amorphous glass structure composed of P, O, Ca, and Cu elements. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed strong cytotoxicity for tumoral cells A375 even in low concentrations for Cu-treatment. In contrast, the copper-free matrix (without Cu) determined a proliferative effect of over 70% viability for all concentrations used.

"Yellow" laccase from Sclerotinia sclerotiorum is a blue laccase that enhances its substrate affinity by forming a reversible tyrosyl-product adduct

Yellow laccases lack the typical blue type 1 Cu absorption band around 600 nm; however, multi-copper oxidases with laccase properties have been reported. We provide the first evidence that the yellow laccase isolated from Sclerotinia sclerotiorum is obtained from a blue form by covalent, but nevertheless reversible modification with a phenolic product. After separating the phenolics from the extracellular medium, a typical blue laccase is obtained. With ABTS as model substrate for this blue enzyme, a non-natural purple adduct is formed with a spectrum nearly identical to that of the 1:1 adduct of an ABTS radical and Tyr. This modification significantly increases the stability and substrate affinity of the enzyme, not by acting primarily as bound mediator, but by structural changes that also alters the type 1 Cu site. The HPLC-MS analyses of the ABTS adduct trypsin digests revealed a distinct tyrosine within a unique loop as site involved in the modification of the blue laccase form. Thus, S. sclerotiorum yellow laccase seems to be an intrinsically blue multi-copper oxidase that boosts its activity and stability with a radical-forming aromatic substrate. This particular case could, at least in part, explain the enigma of the yellow laccases.

Fe(III) - Sulfide interaction in globins: Characterization and quest for a putative Fe(IV)-sulfide species

The present study reports findings regarding the contrast between H₂S interaction with bovine hemoglobin (Hb) and horse heart myoglobin (Mb), in terms of binding and dissociation kinetics, affinities, and mechanism. At pH9.5, oxidation of ferric-sulfide adducts in presence of no free sulfide, using hexachloroiridate as oxidant is examined using stopped-flow UV-vis, EPR, vibrational spectroscopy and mass spectrometry. Oxidation of the ferric-sulfide adduct in such conditions occurs with a putative unstable Fe(IV)-sulfide adduct as intermediate that finally leads to a paramagnetic ferric species with distinct EPR features. As detected by MS spectrometry, this final species appears to be a truncated form of globin at a distinct Tyr. In case of Hb, only β-chain is truncated at Tyr144.

In vivo evaluation of hemerythrin-based oxygen carriers: Similarities with hemoglobin-based counterparts

We have previously proposed the annelid-derived protein, hemerythrin, as a viable replacement for hemoglobin in the synthesis of semi-synthetic oxygen carriers ("blood substitutes"). Here, we report the first in vivo tests for potential hemerythrin-based oxygen carriers (HrBOC), using a battery of experiments involving Wistar rats and previously tested on a series of hemoglobin-based oxygen carrier candidates (HBOC). At the concentrations tested, hemerythrin appears to behave similarly to hemoglobin - including, importantly, immunological effects. The antioxidant strategies based on albumin as well as based on rubrerythrin appear to offer observable physiological advantages.

Chlorite reactivity with myoglobin: Analogy with peroxide and nitrite chemistry?

Stopped-flow UV-vis data allow for the first time direct spectroscopic detection of a ferryl species during the reaction of met myoglobin (Mb) with chlorite, analogous to what is observed in the reaction with peroxides. Ferryl is also observed in the reaction of oxy Mb+chlorite. A pathway involving Fe-O-O-ClO₂ is explored by analogy with the Fe-O-O-NO and Fe-O-O-NO₂ previously proposed as intermediates in the reactions of oxy globins with nitric oxide and nitrite, respectively. However, Fe-O-O-ClO₂ is not detectable in these stopped-flow experiments and is in fact, unlike its nitrogenous congeners, predicted by density functional theory (DFT) to be impossible for a heme complex. Deoxy Mb reacts with chlorite faster than met - suggesting that, unlike with hydrogen peroxide (with which deoxy Mb reacts slower than met), binding of chlorite to the heme is not a rate-determining step (hence, most likely, an outer-sphere electron transfer mechanism); to correlate this, a Fe-O-Cl-O adduct was not observed experimentally for the met or for the deoxy reactions - even though prior DFT calculations suggest it to be feasible and detectable.

Antioxidant activity evaluation by physiologically relevant assays based on haemoglobin peroxidase activity and cytochrome c-induced oxidation of liposomes

Two new protocols for exploring antioxidant-related chemical composition and reactivity are described: one based on a chronometric variation of a haemoglobin ascorbate peroxidase assay and one based on cytochrome c-induced oxidation of lecithin liposomes. Detailed accounts are given on their design, application, critical correlations with established methods and mechanisms. These assays are proposed to be physiologically relevant and bring new information regarding a real sample, both qualitative and quantitative. The well-known assays used for evaluation of antioxidant (re)activity are revisited and compared with these new methods. Extracts of the Hedera helix L. are examined as test case, with focus on seasonal variation and on leaf, fruit and flower with respect to chromatographic, spectroscopic and reactivity properties. According to the set of assays performed, winter are the most antioxidant, followed by summer leaves, and then by flowers and fruits.

Antioxidant activity evaluation involving hemoglobin-related free radical reactivity

Two methods for the measurement of antioxidant capacity are described: one based on a chronometric variation of a hemoglobin ascorbate peroxidase assay and the other based on electron paramagnetic resonance (EPR) spectra collected upon alkaline treatment of ethanolic samples. The involved chemical mechanisms are discussed, alongside the most important benefits and shortcomings; the assays offer new qualitative and quantitative information on samples of biological as well as synthetic origin.

Anterior cruciate ligament reconstruction and determination of tunnel size and graft obliquity

OBJECTIVE

Increase in ACL (anterior cruciate ligament) reconstructions has led to a higher prevalence of patients with postoperative symptoms which require investigation. We aimed to investigate the utility of magnetic resonance imaging (MRI) and computer tomography (CT) in determining tunnel size and graft obliquity after single bundle ACL reconstruction.

PATIENTS AND METHODS

A retrospective comparison was made on 29 symptomatic knees after anatomic single bundle (trans AM) and transtibial ACL reconstructions which had both MRI and CT scans at an average of 1.3 years postoperatively (2 months-5.7 years). We compared CT and MRI (T2 sequence) tunnel size and graft obliquity estimates using Pearson correlation and t-test. We also compared MRI's of ACL reconstructed knees with hamstrings or patellar autografts, which were confirmed by operative protocol as either antero-medial (AM) technique (n=21) or trans-tibial (TT) technique (n=19). The surgeries were performed for an average of 6.29 (4-10) years for the TT group and 1.3 (0-3) years for the AM group, respectively. The graft inclination was measured relative to the tibial plateau using DICOM software. Statistical analysis used the mean value for each case and the data were processed using the non-parametric Kruskal-Wallis test to determine the difference in graft obliquity and tunnel placement.

RESULTS

Tunnel size estimates correlate well between CT and MRI on axial scans: R2=0.795 and 0.630 for femur and tibia respectively. The position of the tunnels and graft obliquity were found to differ on MRI images in both coronal and sagittal planes. Coronal graft obliquity averaged 72.38° (ranging from 69° to 76°) using the AM technique and 75.47° (ranging from 72° to 78°) with TT technique. Sagittal graft inclination angle was 54.5 (51-58.5) and 63.68 (59-69.5) respectively. MRI proves to be the most useful imaging method in determining outcome after ACL reconstruction. However, for a better revision of the ACL reconstructions, CT can offer a clearer image of tunnels and bone stock. A more anatomical graft positioning increases obliquity in coronal and sagittal planes and, thus, becomes difficult to assess both tunnels in a single slice.

CONCLUSIONS

The anatomic single bundle reconstruction technique has been found to more accurately reproduce the femoral footprint and the orientation of the graft compared to the TT technique where the appropriate tibial tunnel placement resulted in a more vertical graft.

Involvement of ferryl in the reaction between nitrite and the oxy forms of globins

The reaction between nitrite and the oxy forms of globins has complex autocatalytic kinetics with several branching steps and evolves through chain reactions mediated by reactive species (including radicals) such as hydrogen peroxide, ferryl and nitrogen dioxide, starting with a lag phase, after which it proceeds onto an autocatalytic phase. Reported here are UV-Vis spectra collected upon stopped-flow mixing of myoglobin with a supraphysiological excess of nitrite. The best fit to the experimental data follows an A → B → C reaction scheme involving the formation of a short-lived intermediate identified as ferryl. This is consistent with a mechanism where nitrite binds to oxy myoglobin to generate an undetectable ferrous-peroxynitrate intermediate, whose decay leads to nitrate and ferryl. The ferryl is then reduced to met by the excess nitrite. DFT calculations reveal an essentially barrierless reaction between nitrite and the oxy heme, with a notable outer-sphere component; the resulting metastable ferrous-peroxynitrate adduct is found to feature a very low barrier towards nitrate liberation, with ferryl as a final product-in good agreement with experiment.

Oxidative protection of hemoglobin and hemerythrin by cross-linking with a nonheme iron peroxidase: potentially improved oxygen carriers for use in blood substitutes

The nonheme peroxidase, rubrerythrin, shows the ability to reduce hydrogen peroxide to water without involving strongly oxidizing and free-radical-creating powerful oxidants such as compounds I and II [formally Fe(IV)] formed in peroxidases and catalases. Rubrerythrin could, therefore, be a useful ingredient in protein-based artificial oxygen carriers. Here, we report that the oxygen-carrying proteins, hemoglobin (Hb) and hemerythrin (Hr), can each be copolymerized with rubrerythrin using glutaraldehyde yielding high molecular weight species. These copolymers show additional peroxidase activity compared to Hb-only and Hr-only polymers, respectively and also generate lower levels of free radicals in reactions that involve hydrogen peroxide. Tests on human umbilical vein endothelial cells (HUVEC) reveal slightly better performance of the Rbr copolymers compared to controls, as measured at 24 h, but not at later times.

Arthroscopic debridement compared to intra-articular steroids in treating degenerative medial meniscal tears

OBJECTIVES

Virtually all early cases of knee osteoarthritis have degenerative medial meniscus lesions accompanying the chondral defects on MRI. It is difficult to determine if the symptoms are caused by the unstable meniscus or by osteoarthritis, hence unclear guidance towards treatment. We, therefore, aimed to determine the clinical improvement following arthroscopic meniscectomy compared to intraarticular administration of corticosteroids for degenerative ruptures of the medial meniscus in the presence of early stage medial compartment knee osteoarthritis.

PATIENTS AND METHODS

We included 120 consecutive cases of nontraumatic symptomatic knees which had degenerative lesions of the medial compartment (cartilage and meniscus) on MRI's. They were randomized to receive either intraarticular steroid injection or arthroscopic debridement. We also analyzed the correlation between BMI, age, gender, MRI, intraoperative aspect of the meniscus and cartilage and clinical improvement using the Oxford Knee Score up to one year. At one month there was significant improvement of the scores for all the examined cases. Also at one month, the arthroscopic group performed better in terms of symptom improvement. This was maintained for 79% of the knees in the arthroscopic group and 61% in the intraarticular steroid injection respectively, out of those available for follow up at one year.

RESULTS

At one month, symptoms reappeared for 12 patients in the steroid group and 7 in the arthroscopy respectively. Gender and age did not correlate with treatment, whereas extrusion of the meniscus, bone marrow edema, duration of the clinical symptoms, obesity and a low preoperative score were negative prognostic factors.

CONCLUSIONS

Degenerative medial meniscal tears, in the presence of osteoarthritis, can only marginally benefit from arthroscopic debridement over intraarticular steroid injections in short term follow up. When considering individual cases, factors become more predictive when analyzed in group.

Photoprotective effects of Romanian propolis on skin of mice exposed to UVB irradiation

We aimed at investigating the antioxidant, antiinflamatory, antiapoptotic and antigenotoxic effects of a Romanian Propolis (RP) extract in two concentrations (RP1 3 mg, respectively RP2 1.5 mg polyphenols/cm(2)), topically administered, either prior to or after UVB exposure, in a Swiss mouse model. Our results showed that both concentrations of RP extract, independent of the time of administration, significantly attenuated the malondialdehyde (MDA) formation and restored glutathione peroxidase (GPx) activity. However, the 8-hydroxy-2-deoxy-guanosine (8-oxo-dG), nitric oxide (NO) and glutathione (GSH) levels were not influenced by UVB exposure and RP treatment. Interleukin (IL)-6 levels were significantly decreased by RP treatment, both before and after UVB-exposure. RP2 extract, in both regimens, significantly reduced the epidermal hyperplasia and dermal inflammation, whereas RP1 pre-treatment diminished only the dermal inflammation. The effect of our RP extract in terms of reduction of sunburn cell formation and of activated caspase-3 and TUNEL-positive cells was observed in both subsets of the experiment, RP2 having a slightly better protective effect as compared to RP1. The antigenotoxic effect of RP was demonstrated by significantly reduced cyclobutane pyrimidine dimers (CPDs) formation. Our results suggest that RP extract might be a potential chemopreventive candidate by modulation of multiple UVB-induced signaling pathways in skin.

Gamma radiation effects on seed germination, growth and pigment content, and ESR study of induced free radicals in maize (Zea mays)

The effects of gamma radiation are investigated by studying plant germination, growth and development, and biochemical characteristics of maize. Maize dry seeds are exposed to a gamma source at doses ranging from 0.1 to 1 kGy. Our results show that the germination potential, expressed through the final germination percentage and the germination index, as well as the physiological parameters of maize seedlings (root and shoot lengths) decreased by increasing the irradiation dose. Moreover, plants derived from seeds exposed at higher doses (≤0.5 kGy) did not survive more than 10 days. Biochemical differences based on photosynthetic pigment (chlorophyll a, chlorophyll b, carotenoids) content revealed an inversely proportional relationship to doses of exposure. Furthermore, the concentration of chlorophyll a was higher than chlorophyll b in both irradiated and non-irradiated seedlings. Electron spin resonance spectroscopy used to evaluate the amount of free radicals induced by gamma ray treatment demonstrates that the relative concentration of radiation-induced free radicals depends linearly on the absorbed doses.

Polyphenolic composition, antioxidant and antibacterial activities for two Romanian subspecies of Achillea distans Waldst. et Kit. ex Willd

The aim of this work was to study the chemical composition, antioxidant and antibacterial properties of Achillea distans Waldst. et Kit. subsp. distans and Achillea distans Waldst. et Kit. subsp. alpina Rochel, from the Rodna Mountains (Romania). The identification and quantification of major phenolic compounds was performed by a HPLC-MS method. The total polyphenolic and flavonoid content was determined spectrophotometrically. The antioxidant activity was evaluated using the DPPH bleaching method, trolox equivalent antioxidant capacity assay (TEAC), hemoglobin ascorbate peroxidase activity inhibition (HAPX) assay, and an Electron Paramagnetic Resonance (EPR) spectroscopy method. A data indicated that A. distans subsp. alpina extract has more antioxidant activity than A. distans subsp. distans extract. Luteolin, apigenin, quercetin, caffeic and chlorogenic acids were present in the two extracts of A. distans, but in different amounts. Three flavonoids were detected only in A. distans subsp. alpina. The polyphenol-richer A. distans subsp. alpina extract showed a higher antioxidant activity than A.distans subsp. distans extract. A.distans subsp. distans extract showed inhibitory activity for Gram-positive bacteria, as evaluated with four species. The quantitative and qualitative differences between the two subspecies of Achillea distans could be used as a potential taxonomic marker in order to distinguish the species.

Hemoglobin-albumin crosslinked copolymers: reduced prooxidant reactivity

We have previously reported that derivatization of hemoglobin with periodate-modified sugar derivatives such as oxidized adenosine triphosphate (oATP) leads to an increase in prooxidant reactivity at the heme. Here, we report that copolymerization of hemoglobin with serum albumin alleviates this problem completely, to the extent where the copolymer even has a slightly lower autooxidation rate compared to native hemoglobin. A similar, although not as potent, effect is obtained when hemoglobin is derivatized with oATP in the presence of small-molecule antioxidants instead of albumin.

Ascorbate peroxidase activity of cytochrome c

The peroxidase-type reactivity of cytochrome c is proposed to play a role in free radical production and/or apoptosis. This study describes cytochrome c catalysis of peroxide consumption by ascorbate. Under conditions where the sixth coordination position at the cytochrome c heme iron becomes more accessible for exogenous ligands (by carboxymethylation, cardiolipin addition or by partial denaturation with guanidinium hydrochloride) this peroxidase activity is enhanced. A reaction intermediate is detected by stopped-flow UV-vis spectroscopy upon reaction of guanidine-treated cytochrome c with peroxide, which resembles the spectrum of globin Compound II species and is thus proposed to be a ferryl species. The ability of physiological levels of ascorbate (10-60 µM) to interact with this species may have implications for mechanisms of cell signalling or damage that are based on cytochrome c/peroxide interactions.

Derivatization of haemoglobin with periodate-generated reticulation agents: evaluation of oxidative reactivity for potential blood substitutes

Periodate modification of the sugar moiety in sugars, including adenosine triphosphate (ATP), has previously been employed in order to prepare dialdehyde-type reagents, which were then utilized in crosslinking reactions on haemoglobin, yielding polymerized material with useful dioxygen-binding properties and hence proposed as possible artificial oxygen carriers ('blood substitutes'). Here, the periodate protocol is shown to be applicable to a wider range of oxygen-containing compounds, illustrated by starch and polyethylene glycol. Derivatization protocols are described for haemoglobin with such periodate-treated crosslinking agents, and the dioxygen-binding properties and redox reactivities are investigated for the derivatized haemoglobins, with emphasis on pro-oxidative properties. There is a general tendency of the derivatization to result in higher autooxidation rates. The peroxide reactivity of the met (ferric) form is also affected by derivatization, as witnessed, among others, by varying yields of ferryl [Fe (IV)-oxo] and free radical generated. In cell, culture tests (human umbilical vein epithelial cells, HUVEC), the derivatization protocols show no toxic effect.

Redox reactivity in propolis: direct detection of free radicals in basic medium and interaction with hemoglobin

Propolis is one of many natural products with known antioxidant properties. The present work aims to investigate the intimate molecular-level mechanisms of this antioxidant reactivity. Electron paramagnetic resonance (EPR)-detectable free radical signals are described here for the first time in propolis extracts. The shape of these signals and the conditions in which they were obtained, point to polyphenolic flavonoids as the sites of the radicals. An inverse correlation between antioxidant capacity and free radical signal intensity is shown. The free radical reactivity of propolis is also illustrated by the effect it exerts on the biologically-relevant peroxide reactivity of hemoglobin. A new test of antioxidant ability in natural extracts such as propolis is proposed, based on modulation of the ascorbate peroxidase activity of hemoglobin (HAPX). Results of this test correlate well with those obtained via traditional methods such as those based on DPPH (2,2-diphenyl-1-picrylhydrazyl), or on ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid).

'Super-reduced' iron under physiologically-relevant conditions

EPR spectroscopy is employed to demonstrate chemical production of formally Fe(i) and Fe(0) states of phthalocyanines in water at room temperature, and physiologically-relevant pH.

Rotational Correlation Times of 3-Carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy Spin Label with Respect to Heme and Nonheme Proteins

Noncovalent spin labeled proteins (ovalbumin, bovine serum albumin, hemoglobin, and cytochrome c) were investigated in order to follow the different type of interactions between the nitroxide radical of 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy spin label and functional groups of heme and nonheme proteins as well as the pH influence on molecular motion of the label with respect to these proteins. EPR spectra were recorded at room temperature and the computer simulation analysis of spectra was made in order to obtain the magnetic parameters. Noncovalent labeling of proteins can give valuable information on the magnetic interaction between the label molecule and the paramagnetic center of the proteins. The relevance of this interaction can be obtained from line shape analysis: computer simulations for nonheme proteins assume a Gaussian line shape, whereas for heme proteins, a weighted sum of Lorentzian and Gaussian components is assumed. In the framework of the "moderate jump diffusion" model for rotational diffusion, the rotational correlation time is strongly influenced by pH, because of the electrostatic interactions and hydrogen bonding.

EPR study of non-covalent spin labeled serum albumin and hemoglobin

Electron Paramagnetic Resonance (EPR) was used to investigate the Tempyo spin label (3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy) as a report group for the interactions and the conformational changes of lyophilized bovine serum albumin (BSA) and bovine hemoglobin (BH), as function of pH values in the range 2.5-11. The EPR spectra are similar with those of other non-covalently spin label porphyrins in frozen solution at very low temperatures. This behavior indicated a possible spin-spin interaction between the hemic iron and the nitroxide group. The changes in the EPR spectra as function of the pH are discussed in terms of conformational changes of the proteins. Spectral simulations and magnetic EPR parameters reveal the following: (i) one single paramagnetic species, with Gaussian line shape, was used for the best fits of experimental spectra in the case of serum albumin samples; and (ii) a weighted sum of Lorentzian and Gaussian line shape in the case of hemoglobin samples. The representation of correlation time vs. pH, reveals a dependence of degree of immobilization of spin label on the conformational changes of proteins in acidic and basic environment.

Local structure analysis of Cu(II)-diazepam complexes by ESR spectroscopy

CuL(2)X(2) (L = 7-chloro-1,3-dihydro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one, also known as diazepam, X = Cl, Br) complexes have been prepared and investigated by ESR spectroscopy. Powder ESR spectra of these complexes suggest a planar-rhombic distorted local symmetry. The CH(3)Cl solutions spectra show the presence of pseudo-tetrahedral species with a 3d(xy)+4p(z) mixture ground state for the paramagnetic electron. The anisotropic spectra obtained for the Cu(II)-diazepam solution adsorbed on NaY zeolite confirm the existence of a CuN(2)X(2) chromophore.