Evaluation of antibacterial activity of macrocyclic metal complexes derived from dihydrazone and diketone.

Synthesis of macrocyclic metal complexes of Cr(III) and Fe(III) by the condensation of benzil dihydrazone with 1H-indole-2, 3-dione.The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, thermal analysis, ESR, infrared, 1H NMR and UV-visible spectroscopy. On the bases of these studies, a five-coordinate square pyramidal geometry is proposed for all the metal complexes. In vitro antibacterial activity of macrocyclic metal complexes exhibited good results.

Piperazine constituents in fruits of Physalis alkekengi var. francheti / 中草药

Objective: To study the chemical constituents in the fruits of Physalis alkekengi var francheti. Methods: The piperazine constituents were isolated and purified with repeated silica gel column chromatography and RP-preparative HPLC. Their structures were determined by NMR spectroscopy. Results: Thirteen compounds were isolated and elucidated as (3S, 6R)-3-isopropyl-6-(2- methyl propyl)-2, 5-piperazine diketone (1), (3S, 6S)-3-isobutyl-6-isopropyl-2, 5-piperazine diketone (2), (3S, 6S)-3, 6-two(2-methyl propyl)-2, 5-piperazine diketone (3), (3S, 6S)-3, 6-di-isopropyl-2, 5-piperazine di-ketone (4), (3S, 6R)-3-(2-methyl propyl)-6-benzyl- 2, 5-piperazine diketone (5), (3S, 6S)-3-isobutyl-6-benzyl-2, 5-piperazine diketone (6), (3S, 6S)-3-isopropyl-6-(p-hydroxy benzyl)-2, 5-piperazine diketone (7), (3S, 6R)-3-isopropyl-6-(p-hydroxy benzyl)-2, 5-piperazine diketone (8), (3S, 6R)-3-(2-methyl propyl)-6- (p-hydroxy benzyl)-2, 5-piperazine diketone 9), (3S, 6S)-3-isobutyl-6-(p-hydroxy benzyl)-2, 5-piperazine diketone (10), (3S, 6S)-3- isopropyl-6-benzyl-2, 5-piperazine diketone (11), (3S, 6R)-3-isobutyl-6-(2-methyl propyl)-2, 5-piperazine diketone (12), and (3S, 6S)-3-benzyl-6-(p-hydroxy benzyl)-2, 5-piperazine diketone (13). Conclusion: Compounds 1-13 are firstly obtained from this plant.

Diketopinic acid-a novel reagent for the modification of arginine§.

Diketopinic acid has been synthesized and shown to be a reagent of choice for specific, reversible modification of the guanidine groups of arginine residues. Diketopinic acid is a yellow crystalline substance and the carboxyl group of the reagent is a convenient handle for attachment to other molecules. The adducts of diketopinoyl derivatives with the guanidine group are cleaved by 0·2 M o-phenylenediamine at pH 8–9. The modification and regeneration of arginine and of arginyl residues in soyabean trypsin inhibitor and insulin are presented as demonstrations of the use of the reagent. The use of diketopinoyl resin in the separation of oxidized A and B chains of insulin has been discussed.