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A detailed NMR, CD, fluorometry, and molecular modeling study of a novel bradykinin antagonist B-9340, containing a novel amino acid d-Igl (α-(2-indanyl)glycine) at position 7, was carried out. The sequence of B-9340 is d-Arg⁰-Arg¹-Pro²-Hyp³-Gly⁴-Thi⁵-Ser⁶-d-Igl⁷-Oic⁸-Arg⁹, where Hyp is hydroxyproline, Thi is β-(2-thienyl)alanine, and Oic is (3aS,7aS)-octahydroindole-2-carboxylic acid. The CD results exhibit a striking effect of SDS on the spectrum of the BK antagonist, indicating that interaction with the surfactant induces a folded peptide structure. The interaction of this antagonist with phosphatidylinositol was monitored by fluorometry, indicating that the interaction of the peptide with the lipid is cooperative, and gives a Hill coefficient of 2.3. The two-dimensional proton NMR measurements indicate that B-9340 has no stable secondary structure in water solution and contains about 10−15% cis peptide bonds arising from Pro², Hyp³, and Oic⁸. In SDS micelles, NMR reveals the existence of two β-turns based on a number of medium-range connectivities that were useful for molecular modeling. The actual molecular modeling and dynamic runs were performed on B-9340 in an environment consisting of a layer of octyl sulfate anions and water. The results indicate that the structure of B-9340 in a micellar environment is characterized by a nonideal βII-turn comprising residues Pro² to Thi⁵, a nonideal βII‘-turn comprising residues Ser⁶−Arg⁹, and broad folding in the middle part of the molecule. The structure is stabilized by several hydrogen bonds and by a salt bridge between the guanidine moiety of Arg¹ and the carboxyl group of Arg⁹, whereas the middle part of the peptide is buried in the micelle. The structure is deposited as Brookhaven PDB file 1 BDK.

Since the hot pressing of ZrB2compacts has a number of limitations, the possibility of pressureless sintering by the addition of small amounts of various metals to provide a liquid phase has been investigated. Changes in microstructure and porosity of the compacts have been studied. Additions of up t0 3% of iron, nickel, cobalt, or high-melting-point metals enable satisfactory sintering at 2000°C in argon or in vacuum to be achieved in < 60 min. The effect is associated with an appreciable contraction of the ZrB2lattice.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The title reaction of the ketone (I) yields the products (IV)‐(VI) via Baeyer‐Villiger oxidation or the hydroxy ketone (VII) depending on the concentration of H2SO4.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The conformation of the title ketols, e.g. (II) (no yield given) and (III), of acetoxy ketones such as (V) and (X) and of diol acetates like (VIII) and (IX) is determined by 1H NMR and IR spectra.

The photolysis of the epoxyoleanol nitrite (I) affords the oximes (II) and (III) by functionalization of the 10β‐methyl group as well as of the rather distant 8β‐methyl group.

The title compound (II) is prepared by hydroxylation and reduction of the ketone (I) which in turn is synthesized from betulin by a sequence of known reactions.