Simeon Popov

Chemical composition and antibacterial activity of Brazilian propolis.

Four samples of Brazilian propolis were investigated by GC/MS of different fractions. 32 volatile compounds, (10 of them new for propolis), as well as 12 more polar compounds (one of them new for propolis) were identified. Antibacterial activity was found in some propolis fractions.

Immunomodulatory action of propolis. IV: Prophylactic activity against gram-negative infections and adjuvant effect of the water-soluble derivative

The efficacy of the water-soluble derivative (WSD) of natural propolis (bee glue) was examined for augmentation of host resistance against experimental infections caused by Gram-negative pathogens (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa). The substance was found to induce significant non-specific protection, but did not inhibit the in vitro growth of the same strains. Pretreatment with WSD prior to the standard scheme for tumour necrosis factor (TNF) induction (BCG and two weeks later lipopolysaccharide (LPS)) provoked an interval-dependent reduction in the lytic capacity of serum against L 929 target cells. The replacement of the triggering or priming signal with WSD markedly increased TNF production. In vivo administration of WSD led to a rapid and route-dependent change in the alternative complement pathway haemolysis. The alteration in C1q complement component and total protein synthesis, and also in nitroblue tetrazolium reduction, suggests that macrophage activation makes a major contribution to the capacity of WSD to prevent infections.

Phytochemical Evidence for the Plant Origin of Brazilian Propolis from São Paulo State

Abstract Propolis and plant secretions from three species, most frequently mentioned as botanical sources of the bee glue in Brazil (Baccharis dracunculifolia, Araucaria angustifolia and Eucalyptus citriodora) have been investigated using GC-MS. Based on chemical evidence, B. dracunculifolia was shown to be the main propolis source in São Paulo state. The antibacterial and antifungal activities of all four materials were also tested, the most active being propolis and Baccharis leaf exudate.

ANTIBACTERIAL DITERPENIC ACIDS FROM BRAZILIAN PROPOLIS

Abstract Four labdane-type diterpenic acids and syringaldehyde were isolated and identified from Brazilian propolis. A ll the compounds exhibit antibacterial activity. The diterpenes, found for the first time in propolis, are typical for some Araucaria species and thus indicate a possible plant source of Brazilian propolis.

Phospholipid studies of marine organisms: V1 new α-methoxy acids fromHigginsia tethyoides

The phospholipids of the demospongeHigginsia tethyoides are shown to have at least 16 long-chain α-methoxy acids, which represent a new class of fatty acids. Among them are the saturated α-methoxy acids containing 19–24 carbon atoms. The monounsaturated compounds are 2-OMe-Δ17-24:1, 2-OMe-Δ18-25:1, 2-OMeΔ19-26:1 and 2-OMe-Δ21-28:1. The major diunsatured ones were shown to be 2-OMe-Δ5, 19-26:2 and 2-OMe-Δ7, 21-28:2. Small amounts of 2-OMe-23∶1, 2-OMe-26∶3; 2-OMe-27∶1 and 2-OMe-28∶3 were also encountered. Structures of the minor monounsaturated compounds were tentatively assigned as 2-methoxy-16-tricosenoic acid and 2-methoxy-20-heptacosenoic acids. The double bonds of the fatty acids show all-cis configuration. Circular dichroism measurements indicate an R-configuration for the α-methoxy acids. The major component of the total phospholipid acid mixture is 5,9,23-triacontatrienoic acid. Possible biosynthetic routes to these unusual phospholipid acids are discussed. The major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine. The distribution of fatty acids among the phospholipids was also investigated.

High-performance liquid chromatographic analysis of flavonoids from propolis

Abstract A simple high-performance liquid chromatographic procedure using a reversed- phase column and an internal standard has been developed for the qualitative and quantitative analysis of flavonoids from the bee-hive product propolis. The method can be applied even to flavonoids that produce overlapping peaks.

Determination of phenolics from propolis by capillary gas chromatography

Abstract A procedure using capillary gas chromatography with an internal standard has been developed for the determination of the main biologically active phenolics of propolis (bee glue): the flavonoid aglycones pinocembrin and galangin, and caffeic acid and its β-phenyl-ethyl ester.

The fatty acids of the spongeDysidea fragilis from the black sea

The fatty acid composition of the sponge,Dysidea fragilis, from the Black Sea has been determined by analytical gas chromatography, silver ion high-performance liquid chromatography and gas chromatography/mass spectrometry. More than a hundred different fatty acids were identified, of which many were similar to those in sponges from tropical seas. On the other hand, some of the fatty acids identified have not been found previously in sponges or other marine sources and perhaps are new to science. These include 13-methyl-tetradec-4-enoic and 14-methyl-hexadec-6-enoic acids, together with demospongic acids,i.e. 5,9,17-tetracosatrienoic, 5,9,17-pentacosatrienoic and 5,9,19-pentacosatrienoic acids. From the elution behavior on silver nitrate chromatography, all the double bonds were of thecis-configuration.

Isopentenyl cinnamates from poplar buds and propolis

Abstract From Populus nigra buds, P. italica buds and propolis, two esters of caffeic acid and two esters of ferulic acid with isomeric pentenyl alcohols have been isolated and their structures elucidated.

Cyclic peptides from a Ruegeria strain of bacteria associated with the sponge Suberites domuncula.

Two new cyclic peptides, cyclo-(glycyl-L-seryl-L-prolyl-L-glutamyl) and cyclo-(glycyl-L-prolyl-L-glutamyl), have been isolated from the cell extract of a Ruegeria strain associated with cell cultures of Suberites domuncula. Three other cyclopeptides have been isolated for the first time from a natural source. Additionally, a new diastereoisomer of a known compound is reported. The structures of isolated compounds have been elucidated by means of spectroscopic data (1D-, 2D-NMR, HRESIMS) and chiral HPLC analysis. The new cyclopeptides exhibited moderate antimicrobial activity against Bacillus subtilis.