Ivan Vučković

Diarylheptanoids from the bark of black alder inhibit the growth of sensitive and multi-drug resistant non-small cell lung carcinoma cells.

An extended study of minor diarylheptanoids from the bark of black alder has resulted in the isolation of twenty diarylheptanoids, ten of which have not previously been reported (14-18, 20-24). The structures and configurations of all compounds were elucidated by NMR, HRESIMS, UV, IR, and CD. The anti-cancer potency of twenty diarylheptanoids and four previously isolated compounds (7, 10, 12, 13) was investigated in human non-small cell lung carcinoma cell lines (sensitive and multi-drug resistant variants) as well as in normal human keratinocytes. Diarylheptanoids with a p-coumaroyl group, 14 and 18, platyphylloside (1), platyphyllonol-5-O-β-D-xylopyranoside (2), alnuside B (4) and hirsutenone (9) exhibited strong anti-cancer activity, considerably higher than diarylheptanoid curcumin, which served as a positive control. Compounds 4, 9, 14, and 18 displayed significant selectivity towards the cancer cells. Structure/activity analysis of twenty-four closely related diarylheptanoids revealed a high dependence of cytotoxic action on the presence of a carbonyl group at C-3. Substitution of a heptane chain on C-5 and a number of hydroxyl groups in the aromatic rings also emerged as a significant structural feature that influenced their cytotoxic potential.

New anti-cancer characteristics of jatrophane diterpenes from Euphorbia dendroides.

Jatrophane diterpenes were shown to be inhibitors of P-glycoprotein (P-gp). There are also evidences on their microtubule-interacting activity in cancer cells. We evaluated new anti-cancer characteristics of two jatrophane type compounds from Euphorbia dendroides. For that purpose, the model system of sensitive non-small cell lung cancer cell line (NCI-H460) and its resistant counterpart (NCI-H460/R) was used. Although both jatrophanes showed inhibitory effect on cancer cell growth, they were non-toxic for peripheral blood mononuclear cells (PBMC). We examined their effects in combination with paclitaxel (PTX), a well-known mitotic spindle interacting chemotherapeutic. Jatrophanes overcome PTX resistance in concentration-dependent manner in MDR cancer cell line (NCI-H460/R). We observed that this synergistic effect is not caused merely by P-gp inhibition. In combination with PTX, jatrophanes induce cell killing and change cell cycle distribution leading to G2/M arrest. Furthermore, they exert an anti-angiogenic effect by decreasing the vascular endothelial growth factor (VEGF) secretion. The reduction of the level of mdr1 mRNA expression in sensitive cells, suggests that these compounds could not contribute to the development of resistance. In conclusion, present study provides a rational basis for the new cancer treatment approach with jatrophanes that are non-toxic to normal cells and have new favorable anti-cancer characteristics.

Diarylheptanoids from Alnus glutinosa Bark and Their Chemoprotective Effect on Human Lymphocytes DNA

A study of secondary metabolites from the bark of Alnus glutinosa led to the isolation of fourteen diarylheptanoids: oregonin (1), platyphylloside (2), rubranoside A (3), rubranoside B (4), hirsutanonol (5), hirsutenone (6), hirsutanonol-5-O-β-D-glucopyranoside (7), platyphyllonol-5-O-β-D-xylopyranoside (8), aceroside VII (9), alnuside A (10), alnuside B (11), 1,7-bis-(3,4-dihydoxyphenyl)-5-hydroxy-heptane-3-O-β-D-xylopyranoside (12), (5S)-1-(4-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)-5-O-β-D-glucopyranosyl-heptan-3-one (13), and (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-O-β-D-[6-(3,4-dimethoxycinnamoylglucopyranosyl)]-heptan-3-one (14). All of the diarylheptanoids, except 1 and 5, were found in A. glutinosa for the first time, while 13 and 14 were new compounds. The structures were determined by spectroscopic techniques: 1D and 2D NMR, HR-ESI-MS, FTIR, UV, and CD. All isolated compounds were analyzed for an in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using the cytokinesis-block micronucleus assay. The majority of them, including the new compounds 13 and 14, exerted a pronounced effect in decreasing DNA damage in human lymphocytes. Diarylheptanoids 1, 2, 5, 13, and 14 at a concentration of 1 µg/mL decreased the frequency of micronuclei by 52.8 %, 43.8 %, 63.6 %, 44.4 %, and 56.0 %, respectively, exerting a much stronger effect than the synthetic protector amifostine (17.2 %, c = 1 µg/mL).

Composition of the Defensive Secretion in Three Species of European Millipedes

Three European julid species, Cylindroiulus boleti, Leptoiulus trilineatus, and Megaphyllum bosniense, secrete mixtures of up to 12 different quinones. The major components in these species are 2-methoxy-3-methyl-1,4-benzoquinone and 2-methyl-1,4-benzoquinone. 2-Methoxy-5-methylhydroquinone is detected for the first time in the Class Diplopoda. 2-Hydroxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxyhydroquinone, 2-methyl-3,4-methylendioxyphenol, and 2,3-dimethoxy-5-methylhydroquinone are registered for the first time in representatives of the family Julidae. The similar chemical composition of defense secretions in all analyzed European julids and Pacific spirobolids supports the idea of the chemical consistency of defensive compounds in juliform millipedes.

RP TLC-based lipophilicity assessment of some natural and synthetic coumarins

O carater lipofilico de doze cumarinas foi investigado por cromatografia de camada fina de fase reversa (RP TLC) em silica RP-18. Tres diferentes sistemas de solvente binario compostos por agua e o modificador orgânico (metanol, tetrahidrofurano ou acetonitrilo) foram utilizados para determinar o parâmetro de retencao (RM0) e o coeficiente de particao de octanol-agua (log POW) como medida de lipofilicidade dos compostos testados. O parâmetro de lipofilicidade (log POW) foi determinado experimentalmente usando-se oito padroes de soluto com valores de log POW conhecidos, que foram analisados sob as mesmas condicoes cromatograficas de substâncias alvos. Parâmetros de lipofilicidade junto com descritores moleculares 2D foram submetidos a analise estatistica multivariavel (analise de componentes principais (PCA) e regressao por minimos quadrados parciais (SLS)) para determinar os fatores mais importantes para retencao, ou seja, lipofilicidade dos compostos investigados. Os modelos quantitativos de relacao entre as propriedades de estrutura e retencao revelam a importância de descritores referentes ao tamanho e ao formato da molecula assim como suas propriedades polares.

Chemical defense in the cave-dwelling millipede Brachydesmus troglobius Daday, 1889 (Diplopoda, Polydesmidae)

10Faculty of Veterinary Medicine, University of Belgrade, Bulevar Oslobodjenja 18, 11000 Belgrade, Serbia (iris@vet.bg.ac.rs) Makarov S.E. , Vujisić L.V., Ćurčić B.P.M., Ilić B.S., Tešević V.V., Vajs V.E., Vučković I.M., Mitić B.M., Lučić L.R. and Đorđević I.Ž. 2012. Chemical defense in the cave-dwelling millipede Brachydesmus troglobius Daday, 1889 (Diplopoda, Polydesmidae). International Journal of Speleology, 41(1), 95-100. Tampa, FL (USA). ISSN 0392-6672. http://dx.doi.org/10.5038/1827-806X.41.1.10

Cytotoxic Guaianolide from Anthemis segetalis (Asteraceae)

Two epimeric guaianolides were isolated from the aerial parts of Anthemis segetalis. These compounds have not been detected in any Anthemis species so far. One of them was tested for cytotoxicity against human cervical cancer (HeLa) and murine melanoma (B16) cell lines showing appreciable activity. Copyright

Two structurally distinct chalcone dimers from Helichrysum zivojinii and their activities in cancer cell lines

Dimers tomoroside A (1) and tomoroside B (2) of the co-occuring known chalcone monomer (3), along with the seven known flavonoid glucosides (4-10), were isolated from the aerial parts of Helichrysum zivojinii Černjavski & Soška. The structures of the isolated compounds were elucidated by spectroscopic techniques. Compound 1 inhibited topo IIα and hif-1α expression and stimulated doxorubicin anticancer effect, while 2 increased the expression of hif-1α, probably acting as antioxidant and redox status modulator. Notably, 2 synergized with Tipifarnib showing potential to improve the action of this new chemotherapeutic involved in the modulation of mitogene activated protein (MAP) kinase signaling pathway.

Molecular Diversity of Compounds from Pygidial Gland Secretions of Cave-Dwelling Ground Beetles: The First Evidence

Three adult cave-dwelling ground beetle species were induced to discharge secretions of their pygidial glands into vials. Dichloromethane extraction was used to obtain the secretions. In total, 42 compounds were identified by GC/MS analysis. Pheggomisetes ninae contained 32 glandular compounds, Laemostenus (Pristonychus) punctatus 13, whereas Duvalius (Paraduvalius) milutini had nine compounds. Caproic, oleic, palmitic, and stearic acids were present in the samples of all analyzed species. Undecane was predominant in the extract of L. punctatus. Palmitic acid was the major component in the secretion of D. milutini. Finally, the most abundant compounds in P. ninae secretion were heptacosene and nonacosadienes. Herein, we present the first data on the identification of pygidial gland secretion components in both troglophilous and troglobite cave-dwelling ground beetles. Some compounds are reported for the first time in the secretions of ground beetles and other higher or lower taxa. The adaptation to underground life has not led to a reduction or changes in the chemical defense mechanism in the analyzed troglophilous and troglobitic Platyninae and Trechinae taxa.

A New Prenylated Flavanonol from Seseli annuum Roots Showing Protective Effect on Human Lymphocytes DNA

A new prenylated flavanonol named seselinonol (1) was isolated from the roots of Seseli annuum, together with the well‐known biologically active polyacetylenes falcarinol (2) and falcarindiol (3), and the prenylated furanocoumarin phellopterin (4). Its structure was elucidated by extensive spectroscopic analysis, including HR‐ESI‐MS, 1D‐ and 2D‐NMR. Seselinonol and phellopterin were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin‐B blocked micronucleus (CBMN) assay. The new compound exerted a beneficial effect by decreasing DNA damage of human lymphocytes.