PubMed Health⌕ Search

Biomedical subjects

Slobodan Milosavljević

Publications and source records attributed to Slobodan Milosavljević.

5 recordsLinked to original sources

Cytotoxic constituents of Achillea clavennae from Montenegro.

Examination of the aerial parts of Achillea clavennae afforded eight guaianolides (1-8), three bisabolenes (9-11), four flavonols (12-15), sesamin (lignan) and isofraxidin (coumarin). The structures of the new compounds (2, 4, 5, 7 and 10) were determined by spectroscopic methods. The antiproliferative action of 2, 8, 9 and 12 were tested to HeLa, K562 and Fem-X human cancer cell lines. Guaianolides 2 (9alpha-acetoxyartecanin) and 8 (apressin) showed significant cytotoxic effects to all tested lines and inducumenone (9) exhibited a moderate activity. The most active was flavonol centaureidin (12), already known as cytotoxic compound.

Achillea↗

Gibberellic acid nitrite stimulates germination of two species of light-requiring seeds via the nitric oxide pathway.

We used two species of light-requiring seeds, Paulownia tomentosa, which have absolute light requirement (no germination in darkness), and Stellaria media seeds, which germinate in darkness to a certain extent because of presence of preformed active phytochrome, to obtain results strongly suggesting that gibberellic acid nitrite stimulates seed germination via its capability as a functional NO donor. Exogenous application of gibberellic acid nitrite stimulates gibberellin-insensitive Stellaria media seed germination in darkness as do a wide variety of NO donors. Pure gibberellic acid could replace the light requirement of P. tomentosa seeds, thus enabling them to germinate in darkness. Gibberellic acid nitrite did not have this effect. A stimulative effect from gibberellic acid nitrite could be detected only after exposure of these seeds to short, 10 min, pulse of red light. Taken together, these results suggest that gibberellic activity of gibberellic acid nitrite is lost after nitrosation but, regarding to the presence of -O-NO moiety in the molecule, gibberellic acid nitrite shares stimulative properties in seed germination with other compounds with NO-releasing properties.

Dose-Response Relationship, Drug↗

Guaianolides from two subspecies of Amphoricarpos neumayeri from Montenegro.

Quantitative (1)H NMR measurements revealed delta(11(13)) sesquiterpene gamma-lactones as the main constituents ( >or= 1% per weight of dried plant material) in the crude extracts of the aerial parts of Amphoricarpos neumayeri ssp. neumayeri and ssp. murbeckii from mountains Orjen and Visitor (Montenegro), respectively. Preparative silica gel chromatography afforded thirteen guai-11(13)-en-12,6alpha-olides, named amphoricarpolides (1-13), with the same relative (1alphaH,4betaH,5alphaH,7betaH) configuration of the basic skeleton. The common structural feature of lactones 2-13 was 3beta,15-dioxygenation pattern. The only exception was 1 (3-deoxyamphoricarpolide), containing a single oxygen substituent (15-OH). Eight of them exhibited an additional oxygen substituent, 9beta-OH (5 and 6), 2alpha-OH (8-12), or 2alpha-OAc (13). Compound 7 was epoxydated at 10alpha(14)-position, whereas the remaining lactones contained a 10(14) double bond.

Antifungal Agents↗

Hyperatomarin, an antibacterial prenylated phloroglucinol from Hypericumatomarium ssp. degenii.

As shown by quantitative (1)H NMR measurements, a lipophilic extract of the aerial parts of Hypericum atomarium ssp. degenii contained a high percentage (3.1% per weight of dried plant material) of a prenylated phloroglucinol (1). Compound 1, named hyperatomarin, occurring in two tautomeric forms (1a <==> 1b), was isolated by bioactivity-guided preparative TLC and was identified on the basis of spectral data interpretation. This isolated phloroglucinol exhibited activity against Gram-positive (Staphyloccocus aureus and Microccocus luteus) and Gram-positive spore-forming bacteria (Bacillus subtilis and B. IP 5832).

Anti-Infective Agents↗

Xanthones from Swertia punctata.

Isolation of 1-O-primeverosyl-3,8-dihydroxy-5-methoxyxanthone and 1-O-gentiobiosyl-3,7-dimethoxy-8-hydroxyxanthone, along with five known xanthones, isobellidifolin, methylbellidifolin, isoswertianin, methylswertianin and norswertianin-1-O-beta-D-glucoside, from the roots of Swertia punctata is reported. In the aerial parts four xanthones, bellidifolin, methylbellidifolin, swertianolin and mangiferin, and flavone-C-glucoside, isoorientin were identified. The chemotaxonomic and pharmacological significance of these results is discussed.

Molecular Structure↗