Dodecaborate anions of the type B12X122− and B12X11Y2− (X=H, Cl, Br, I and Y=OH, SH, NH3+, NR3+) form strong (Ka up to 106 L mol−1, for B12Br122−) inclusion complexes with γ-cyclodextrin (γ-CD). The micromolar affinities reached are the highest known for this native CD. The complexation exhibits highly negative enthalpies (up to −25 kcal mol−1) and entropies (TΔS up to −18.4 kcal mol−1, both for B12I122−), which position these guests at the bottom end of the well-known enthalpy-entropy correlation for CDs. The high driving force can be traced back to a chaotropic effect, according to which chaotropic anions have an intrinsic affinity to hydrophobic cavities in aqueous solution. In line with this argument, salting-in effects revealed dodecaborates as superchaotropic dianions.

In a new propolis type, red Brazilian propolis, 14 compounds were identified (six of them new for propolis), among them simple phenolics, triterepenoids, isoflavonoids, prenylated benzophenones and a naphthoquinone epoxide (isolated for the first time from a natural source). Three of the major components demonstrated significant antimicrobial activity, and two (obtained as inseparable mixture) possessed radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH).

Also, two minor isomers were detected 6 3.07 (dt, J = 10, 2.5 Hz) and 6 3.31 (dm, J = I O Hz) in a 95.1:2.6:2.3 ratio. (la,2cr,3a)-N-Methyl-6-isopropylidene-3-propy~-4-cyclohexen~l,2dicarboximide: 'H NMR (CDC13, 200 MHz) 6 0.95 (t, J = 7.2 Hz, 3 H), 1.43-1.89 (m, 4 H), 1.91 (s, 3 H), 2.00 (s, 3 H), 2.29 (m, 1 H), 2.79 ,925,905, 840,790,735 cm-l; MS, m / e 364, 320, 308, 211. (la,2cr,3a)-N-Methyl-S-( tert -butyldimethylsiloxy)-6-isopropylidene-3-propyl-4-cyclohexene-l,2-carboximide: IH NMR (CDC13, 200 MHz) 1.30-1.86 (m. 4 H), 1.96 (s, 3 H), 2.13 (m, 1 H), 2.86 (s, 3 H), 3.06 (dd,

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