Julie Banerji

Lewis-acid-induced electrophilic substitution in indoles with acetone. Part 2

The electrophilic substitution reaction of indole with acetone in the presence of boron trifluoride has been followed and the structures of two of the three products isolated have been established. The structure of compound (1), dimer II, was determined by X-ray diffraction methods as crystals from methanol were monoclinic, space group Cc, and had cell parameters a= 13.383(2), b= 14.064(2), c= 11.638(4)A, β= 114.74(2)°, Z= 4. The structure was refined to a final R value of 0.068.

Antidiarrhoeal activity of carbazole alkaloids from Murraya koenigii Spreng (Rutaceae) seeds

The bioassay guided fractionation of the n-hexane extract of the seeds of Murraya koenigii Spreng (Rutaceae) resulted in the isolation of three bioactive carbazole alkaloids, kurryam (I), koenimbine (II) and koenine (III). The structures of the compounds were confirmed from their (1)H-, (13)C-, and 2D-NMR spectral data. Of the three compounds (I) and (II) exhibited significant inhibitory activity against castor oil-induced diarrhoea and PGE(2)-induced enteropooling in rats. The compounds also produced a significant reduction in gastrointestinal motility in the charcoal meal test in Wistar rats.

Leishmanicidal and Anticandidal Activity of Constituents of Indian Edible Mushroom Astraeus hygrometricus

Two new lanostane‐type triterpenes, 1 and 2, were isolated from Astraeus hygrometricus. The structures were established by IR, 1H‐ and 13C‐NMR, MS, and X‐ray crystallographic experiments. The triterpenes exhibited excellent in vitro toxicities against Candida albicans, comparable to standard antifungal antibiotics. The triterpene 2 significantly inhibited the growth of Leishmania donovani promastigotes in vitro. The triterpene skeleton may be considered a template structure in search for new compounds with anticandidal and leishmanicidal activity.

Saradaferin, a new sesquiterpenoid coumarin from Ferula assafoetida

Phytochemical investigation of the gum resin of Ferula assafoetida resulted in the isolation and characterization of a new sesquiterpenoid coumarin, Saradaferin (1) named as [Decahydro-(3-α-hydroxy-4,4,10-trimethyl-8-methylene-9-naphthenyl)-α-hydroxymethyl] ether of umbelliferone.

1,3-Dipolar Cycloadditions VI (1). Structure and Conformation of Cycloadducts from Reactions of C-Aryl-N-phenylnitrones with Substituted Cinnamic Acid Amides

Summary. Studies on cycloadditions of C,N-diarylnitrones to cinnamic acid amides were carried out. The diastereoisomeric (I, II) and (in some cases) regioisomeric (III) cycloadducts obtained were characterized by spectroscopic and X-ray data. Conformational studies were carried out by molecular modelling.

synthesis of sempervirine, a pentacyclic anhydronium indole alkaloid

SummarySempervirine (2,3,4,13-tetrahydro-1H-benz[g]indolo[2,3-a]quinolizin-6-ium,1) the pentacyclic anhydronium indole alkaloid ofGelsemium sempervirens Ait. f. (Loganiaceae), has been synthesized in three steps from hexahydroisochroman-3-one (6) and N-2-(3-indolyl)-ethylamine (tryptamine,7). The condensation product, N-2-(3-indolyl)-ethyl-2-(hydroxymethyl)-trans-hexahydrophenylacetamide (8) arising from6 and7 on double cyclization with phosphoryl chloride yielded the 3,4-dehydroyohimbane derivative9. Aromatization of rings C and D of compound9 with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in glacial acetic acid, followed by basification, generated sempervirine (1).ZusammenfassungSempervirin (2,3,4,13-Tetrahydro-1H-benz[g]indolo[2,3-a]chinolizin-6-ium,1), das pentacyclische Anhydronium-Indolalkaloid vonGelsemium sempervirens Ait f. (Loganiceae) wurde ausgehend von Hexahydroisochroman-3-on (6) und N-2-(3-Indolyl)-ethylamin (Tryptamin,7) in 3 Stufen synthetisiert. Das durch doppelte Cyclisierung von6 und7 mit Phosphorylchlorid entstehende Kondensationsprodukt N-2-(3-Indolyl)-ethyl-2-(hydroxymethyl)-trans-hexahydrophenylacetamid (8) ergab das 3,4-Dehydroyohimbanderivat9. Aromatisierung der Ringe C und D von9 mit 2,3-Dichlor-5,6-dicyanobenzochinon (DDQ) in Eisessig und anschließende Einstellung eines basischenpH-Werts lieferte Sempervirin (1).

Use of ninhydrin for detection of silylated amino acids

Protein structure elucidation is very dependent on the detection of its constituent amino acids, because these are the structural units of proteins. They are also found in the free state in a different natural products. Several specific and non-specific reagents have been reported for detection of amino acids [1–6]; of these, ninhydrin is a widely accepted non-specific reagent with high sensitivity. The formation of an identical color (purple/violet) with all amino acids except proline and hydroxy proline is, however, a problem if specific detection of the amino acids is required.

Electrophilic substitution reaction of Indole: Part XXII-synthesis of a novel spiro heterocyclic system

The reaction of indole with acetone in the presence of mineral/Lewis acid continues to be a fascinating area for investigation since 1913, specially due to the instability of the indolyl carbinol being generated in situ. We report here the synthesis of a novel spiro heterocyclic system obtained during the study of this reaction using BF 3 .Et 2 0.

Electrophilic Substitution of Indoles. Part 9. Reaction of Indoles with Iminium Systems.

Reactions of indole (II) or 2-methylindole (VII) with the benzylideneanilines (I) yield the products shown in the scheme.