Rijeka, Croatia
Rijeka, Croatia

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Kremer D.,University of Zagreb | Kosir I.J.,Slovenian Institute of Hop Research and Brewing | Koncic M.Z.,University of Zagreb | Cerenak A.,Slovenian Institute of Hop Research and Brewing | And 3 more authors.
Current Drug Targets | Year: 2015

Satureja montana L. and S. subspicata Vis. (Lamiaceae) are used for centuries in traditional medicine of Balcanic people in the healing of the lymphatic nodule and respiratory system inflammation. In this paper the amount of total phenols and flavonoids (analyzed by UV/Vis spectrophotometry), phenolic compounds profile (analyzed by HPLC), antimicrobial and antioxidant activities were studied in samples collected in seven per species populations of S. montana and S. subspicata in Croatia. Eight phenolic compounds (rutin, quercetin, caffeic, p-coumaric, ellagic, protocatehuic, rosmarinic, and syringic acid) were identified and quantified using HPLC in methanolic and ethanolic extracts. Results showed that both species contained polyphenolics and other antioxidant compounds with chelating and radical-scavenging properties. The extracts prepared from both species showed broad spectrum of antimicrobial activity on in vitro tested microbial species (Staphylococcus aureus, Escherichia coli, Candida albicans, C. dubliniensis, C. krusei, C. glabrata, C. parapsilosis, and Microsporum gypseum). © 2015 Bentham Science Publishers.


Dunkic V.,University of Split | Kremer D.,University of Zagreb | Dragojevic Muller I.,Water Supply and Drainage | Stabentheiner E.,University of Graz | And 6 more authors.
Chemistry and Biodiversity | Year: 2012

Satureja montana and S. subspicata are used as spice, pepper substitute, for preparing tea, juice, and as a medicine. Fourteen populations (seven per species) of Satureja montana L. and S. subspicata Vis. growing in Croatia were examined to determine the chemical composition of the essential oil (analyzed by GC-FID and GC/MS), the content of macroelements (Na, K, Ca, Mg) and trace elements (B, Fe, Cu, Mn, Zn, Al, Pb, Cr, Cd, Ni, Hg, As) analyzed by ICP-AES, antioxidant compounds (analyzed by UV/VIS spectrophotometer), and the types and distribution of trichomes (analyzed by scanning electron microscopy). The main constituents of the essential oil were carvacrol and thymol in S. montana (all populations belong to one phenol chemotype), while α-eudesmol, β-eudesmol, and spathulenol dominated in S. subspicata (three chemotypes could be distinguished). Both species possess considerably higher quantities of Ca and Mg, and moderate concentrations of K and Na, while Hg and As levels were below the limit of quantification. Non-glandular trichomes, peltate trichomes, and three types of capitate trichomes were observed on leaves, stem, calyx, and corolla. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.


Kosalec I.,University of Zagreb | Kremer D.,University of Zagreb | Locatelli M.,University of Chieti Pescara | Epifano F.,University of Chieti Pescara | And 4 more authors.
Food Chemistry | Year: 2013

The quantity of phenols, as well as antioxidant and antimicrobial activities, were investigated in bark of Rhamnus alaternus L.; R. fallax Boiss.; R. intermedia Steud. et Hochst.; and R. pumila Turra from natural stands in Croatia. The most abundant anthraquinones in the investigated extracts were chrysophanol in R. alaternus (3.14 mg/g), emodin in R. pumila (0.339 mg/g), and physcion in R. fallax (2.70 mg/g) and R. intermedia (0.285 mg/g). The species exhibiting the highest antioxidant activity were R. fallax and R. pumila. A positive correlation was observed between total phenolic and flavonoid levels of the extracts and antioxidant activity in some of the assays. All species showed antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Aspergillus niger and Microsporum gypseum with minimal inhibitory concentrations equal to or below 2.500 mg/mL. The results indicate that the investigated Rhamnus species are a source of anthraquinones and other phenols, which act as multifunctional antioxidants with antimicrobial activity. © 2012 Elsevier Ltd. All rights reserved.


Locatelli M.,University of Chieti Pescara | Genovese S.,University of Chieti Pescara | Carlucci G.,University of Chieti Pescara | Kremer D.,University of Zagreb | And 2 more authors.
Journal of Chromatography A | Year: 2012

Rhamnus spp. is known to contain biologically active anthraquinone secondary metabolites but the presence of oxyprenylated ones is not reported. To this aim, a new simple, and accurate analytical method was developed to reveal chemical fingerprint of these analytes in plant extracts. Plant samples were analysed after extraction with n-hexane (first step) and methanol (second step) using a C 18 column with a mobile phase composed of 35% of water:65% of methanol (both with 1% formic acid, v/v) at 0.7mLmin -1 flow rate in gradient elution mode. For quantitative analyses, selective detection was performed at 435nm. The limit of quantification (LOQ) was 0.5μM, with the only exception of 3-geranyloxyemodin for which the LOQ value was 5.0μM, and external matrix-matched standard curves showed linearity up to 125μM. The within- and between-batch precision (RSD%) values ranged from 0.2% to 12.9% while within- and between-batch trueness (bias%) values ranged from 12.2% to 12.7%. The method was applied to evaluate for the first time the presence and the quantities of oxyprenylated anthraquinones in Rhamnus spp. barks as well as the anthraquinone profile of Rhamnus pumila Turra. The proposed method could be directly applied to the selective quantification of these analytes in natural sources. © 2012 Elsevier B.V..


Kremer D.,University of Zagreb | Bolaric S.,University of Zagreb | Ballian D.,University of Sarajevo | Bogunic F.,University of Sarajevo | And 8 more authors.
Phytochemistry | Year: 2015

Analysis of the morphological traits of leaves, genetic variability (analyzed by AFLP) and chemical composition of essential oils (analyzed by GC-MS) was conducted on eleven populations of the endemic Illyric-Balcanic species Teucrium arduini L. in Croatia, Bosnia and Herzegovina, and Montenegro. Average blade length and width ranged from 20.00 to 31.47. mm and from 11.58 to 15.66. mm, respectively. Multivariate analysis (PCA, UPGMA) of morphological traits distinguished two continental Bosnian populations from the remaining populations. AFLP analysis separated the investigated populations into two groups based primarily on geographical distance. Essential oil analysis showed a total of 52 compounds, with two chemotypes distinguished based on the essential oil profile. The first was a sesquiterpene chemotype, with β-caryophyllene, germacrene D or caryophyllene oxide as the major compounds, while the second was an oxygenated monoterpene chemotype, with pulegone and piperitone oxide as the main components. The Mantel test showed a stronger correlation between the morphological traits and AFLP than between the essential oil profile and AFLP. The test also showed a stronger association between the essential oil profile and geographical position than between the morphological traits and geographical position. © 2015 Elsevier Ltd.


Kremer D.,University of Zagreb | Lukac G.,Public Institution Paklenica National Park | Brkljacic A.,Public Institution Velebit Nature Park | Brajkovic J.,Croatian Chamber of Commerce | And 2 more authors.
Natura Croatica | Year: 2015

New localities of two endemic, rare and floristically interesting species in the north-western Dinaric Mountains in Croatia are reported in the paper. Both species are statutorily strictly protected species in Croatia. Aquilegia kitaibelii Schott, as a rare, endemic species, is included in Appendix II of the Habitats Directive (NATURA 2000 Species) and in the IUCN list as a data deficient (DD) species. New localities of A. kitaibelii were found on Mt Obruč and the central and south sections of Mt Velebit, while new localities of Cardaminopsis croatica (Schott, Nyman et Kotschy) Jáv. were discovered on hills in the Gacka Region and the central section of Mt Velebit. In general, both species grow mainly from fissures on rocks together with other petrophilous plant species. It was also noted that A. kitaibelii grows on screes. In Gacka Region C. croatica grows in thermophilous habitats, that is, on rocks with different exposures, together with thermophilous sub-Mediterranean species and with some mountain species of common beech and silver fir forests. In the central section of Mt Velebit, C. croatica also grows in a thermophilous community of forest rocks as well as in anthropogenic habitats, like the edges of gravel roads. These observations suggest the ecological adaptability of this endemic species. © 2015, Croatian Natural History Museum. All rights reserved.


Grubesic R.J.,University of Zagreb | Kremer D.,University of Zagreb | Koncic M.Z.,University of Zagreb | Rodriguez J.V.,University of Zagreb | Randic M.,Public institution Priroda
Central European Journal of Biology | Year: 2012

The content of biologically active phenolic compounds (total polyphenols, tannins, flavonoids, and phenolic acids) were determined using spectrophotometry in four wild Croatian species of Daphne L. in the family Thymelaeaceae (Daphne alpina, D. cneorum, D. laureola, and D. mezereum). The concentration of total flavonoids (TF) was highest in the leaves of these Daphne species (0. 12-0. 51% dry herb weight, DW) whereas the content of other phenolic compounds analyzed were highest in the roots, including total polyphenols (TP; 2. 71-19. 03% DW), tannins (T; 1. 14-7. 39% DW), and total phenolic acids (TPA; 0. 12-0. 87% DW). D. alpina contained the highest amount of polyphenols, with the exception of flavonoids, where maximum concentrations were found in D. laureola. We also examined the antioxidant activity of leaf, stem, and root extracts. All extracts analyzed demonstrated high free radical scavenging activity with the highest concentration in the leaf extracts of D. alpina. Leaf extracts of D. cneorum showed the highest antioxidant activity in a β-carotene bleaching assay. © 2012 Versita Warsaw and Springer-Verlag Wien.


Kremer D.,University of Zagreb | Randic M.,Public institution Priroda | Kosalec I.,University of Zagreb | Brkljacic A.,Public institution Velebit Nature Park | And 5 more authors.
Acta Botanica Croatica | Year: 2011

New localities of three subendemic species (Berberis croatica, Teucrium arduini and Micromeria croatica) have been found in the Dinaric Alps. Berberis croatica was found at ten new locations, nine of them in Croatia and one in Bosnia and Herzegovina. Teucrium arduini was found on Mt U~ka, Mt Velebit, Mt Biokovo and Mt Sniježnica, at nine new locations while Micromeria croatica was found at four new locations, only on Mt Velebit. © 2011 by Acta Botanica Croatica, the Faculty of Science, University of Zagreb. All rights reserved.

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