Chittaranjan Das

Bio: Chittaranjan Das is an academic researcher from University of Calcutta. The author has contributed to research in topic(s): Piper & Piperaceae. The author has an hindex of 2, co-authored 2 publication(s) receiving 31 citation(s).

Two amides from Piper brachystachyum

Abstract: Two new unsaturated amides, brachystamides-A and B, were isolated from the total above-ground parts of Piper brachystachyum. Brachystamide-A was shown to be N-isobutyl-15 (3′,4′-methylenedioxyphenyl) 2E,4E-pentadecadienamide from spectroscopic and chemical investigations. Brachystamide-B was N-isobutyl-15 (3′,4′-methylenedioxyphenyl) 2E,4E,14E-pentadecatrienamide.

Synthetic and spectroscopic studies of structural analogues of piper amides — the 5-aryl-2e,4e-pentadienamides.

Abstract: The methyl esters and piperidides of fourteen 5-aryl-2E,4E-pentadienoic acids have been synthesized starting from the corresponding aryl aldehydes.

Phytochemistry of the genus Piper

Abstract: The secondary metabolites isolated from Piper species for the period 1907 to June 1996 have been reviewed. Nearly six hundred chemical constituents belonging to different classes of bioactive compounds are listed together with their source(s) and references. © 1997 Elsevier Science Ltd

Constituents of Chinese Piper species and their inhibitory activity on prostaglandin and leukotriene biosynthesis in vitro.

Abstract: The n-hexane extracts of 19 Piper species, predominantly from China, were screened for their 5-lipoxygenase (5-LOX) and cyclooxygenase-1 (COX-1) inhibitory potential. Many of them showed considerable inhibitory activity against at least one of these two key enzymes of the arachidonic acid metabolism, especially against COX-1. The best results in inhibiting the formation of leukotrienes were obtained with the extract of Piper kadsura. In the terms of prostaglandin synthesis inhibition, the extract of Piper boehmeriifolium var. tonkinense was found to have the strongest activity. Furthermore, an analytical investigation by means of TLC, HPLC-DAD and GC-MS resulted in the identification of 20 constituents. Most of them were amides with an interesting variety of amine moieties. Among them were pellitorine, and four higher homologues, piperlonguminine, dihydropiperlonguminine, futoamide, chingchengenamide, the retrofractamides A, B and D, guineensine, brachystamide B, piperanine, piperine, piperdardine, sarmentine, pipataline and benzylbenzoate. In 96 cases, these constituents were new for the particular plant.

Chemical constituents and bioactivity of Piper sarmentosum.

Abstract: Eight amides, pellitorine (1), guineensine (2), brachystamide B (3), sarmentine (4), brachyamide B (5), 1-piperettyl pyrrolidine (6), 3',4',5'-trimethoxycinnamoyl pyrrolidine (7) and sarmentosine (8), two lignans, (+)-asarinin (9) and sesamin (10), and four other compounds, 1-(3,4-methylenedioxyphenyl)-1E-tetradecene (11), methyl piperate (12) and a mixture of beta-sitosterol (13) and stigmasterol (14), were isolated from the fruits of Piper sarmentosum (Piperaceae). This is the first reported isolation of compounds 2, 3, 5, 6, 7, 9, 10 and 12 from this plant species. Their structures were established from spectral data. These compounds were evaluated in antituberculosis and antiplasmodial tests. The results showed that compounds 4 and 6 exhibited both activities while compounds 1, 2, 5, 8 and 11 showed only antituberculosis activity. This is the first report of the antituberculosis and antiplasmodial activities for these compounds.

Protective effects of amide constituents from the fruit of Piper chaba on D-galactosamine/TNF-α-induced cell death in mouse hepatocytes

Abstract: The methanolic extract from the fruit of Piper chaba (Piperaceae) was found to have a hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. From the ethyl acetate-soluble fraction, a new amide constituent named piperchabamide E together with twenty known amide constituents (e.g., piperine, piperchabamides A-D, and piperanine) and two aromatic constituents were isolated as the hepatoprotective constituents. With regard to structure-activity relationships, the amide moiety and the 1,9-decadiene structure between the benzene ring and amide moiety were suggested to be important for strong inhibition of D-GalN/tumor necrosis factor-alpha (TNF-alpha)-induced death of hepatocytes. Furthermore, a principal amide constituent, piperine, dose-dependently inhibited increase in serum GPT and GOT levels at doses of 2.5-10 mg/kg (p.o.) in D-GalN/LPS-treated mice, and this inhibitory effect was suggested to depend on the reduced sensitivity of hepatocytes to TNF-alpha.