Biswanath Das

Bio: Biswanath Das is an academic researcher. The author has contributed to research in topic(s): Piper & Piperaceae. The author has an hindex of 2, co-authored 2 publication(s) receiving 12 citation(s).

One New and Two Rare Alkamides from Two Samples of the Fruits of Piper longum

Abstract: Two samples of the fruits of Piper longum have been chemically investigated. From one sample a new alkamide, pergumidiene and from other sample two rare alkamides, brachystamide B and piperderdine have been isolated. The known compounds, piperine, piperlonguminine, pellitorine, (+)-sesamine and 3-(3', 4', 5'-trimethoxyphenyl)-propionic acid were the common constituents of both the samples.

Taxoids, Lignans, and Simple Phenolic Compounds from a Sample of the Needles of Himalayan Taxus baccata

Abstract: Chemical investigation on a sample of the needles of Himalayan Taxus baccata has resulted in the isolation of several taxoids including taxol (1) 10-deacetyl-baccatin III (2) and 2-deacetoxytaxinine J (3) along with different lignans (6 and 7) and simple phenolics (8, 9, 10, 11 and 12). The occurrence of 4-(4'-hydroxyphenyl)-butane-2-one and 4-(4'-hydroxyphenyl)-trans-but 3-ene-2-one (8) in Taxus species is reported for the first time. The spectral data of two rearranged taxiod constituents, brevifoliol (4) and 13-decinnamoyltaxchinin B (5) are presented. The acid-catalyzed decomposition of taxol has been discussed. The synthesis of other two constituents, rhododendrol (10) and hibalactone (7) has been described.

Antibacterial Activity of Isolates from Piper longum and Taxus baccata

Abstract: This study describes the antibacterial activity of the pure isolates from Piper longum (L.) (black pepper) and Taxus baccata (L.) (Yew). Three isolates of black pepper were active against Gram-posi...

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.

HPLC assisted chemobiological standardization of α-glucosidase-I enzyme inhibitory constituents from Piper longum Linn-An Indian medicinal plant

Abstract: Formulations of traditional medicines are usually made up of complex mixture of herbs. However, effective quality control methods in order to select right quality materials are lacking. Though Piper longum is a widely used herb in several Ayurvedic formulations prescribed for various diseases, there is no analytical method in the literature so far which can help in selecting the right quality material with proper proportions of the active ingredients (α-glucosidase-I enzyme inhibitory principles). We employed a systematic bioassay guided fractionation method and isolated pipataline, pellitorine, sesamin, brachystamide B and guineensine as active principles. A reversed-phase high-performance liquid chromatography method was developed to quantify these active principles in the plant material, which can serve as an effective quality control tool. The separation was carried out using a Discovery HS F5 C-18 (ODS) column and the solvent system used was a gradient comprising of (A) acetonitrile and (B) water with a flow rate of 1 ml/min. The detection was performed using a PDA detector. Regression equation pertaining to all the bioactive isolates revealed a linear relationship (r2 > 0.9995). The detection limits (S/N = 3) ranged from 0.005 to 0.001 μg/ml. Of all the active isolates, sesamin was identified to be present in maximum quantities (0.91%) where as brachystamide B was found in minimum quantity (0.01%).

Studies on a strain of Kitasatospora sp. paclitaxel producer

Abstract: The strain P&U 22869, which produces paclitaxel and related taxanes, discovered during the course of endophytic actinomycetes screening on Taxus baccata plants, was classified as Kitasatospora sp. on the basis of its morphological characteristics observed by light and scanning electron microscopy, the presence of the major constituents of its cell wall and the 16S rDNA sequence. The morphophysiological profile of the strain was compared with those of the valid and invalid species described for this genus. The paclitaxel production detected by means of monoclonal antibody assay (CIEA) was confirmed by LC-MS analysis and its concentration determined by HPLC. The de novo paclitaxel biosynthesis operated by strain P&U 22869 was demonstrated by biosynthesis experiments with labeled precursors.

Introduction, phytochemistry, traditional uses and biological activity of genus Piper: a review

Abstract: Piper, the pepper plants or pepper vines are an economically and ecologically important genus in the family Piperaceae. It contains about 1,000-2,000 species of shrubs, herbs, and lianas, many of which are keystone species in their native habitat. Piper species have a pan tropical distribution, and are most commonly found in the understory of lowland tropical rainforests, but can also occur in clearings and in higher elevation life zones such as cloud forests. Most Piper species are either herbaceous or vines; some grow as shrubs or almost as small trees. Many species of piper have been used for treating different diseases in many traditions. E.g P. cubeba has been used in folk medicine, herbalism as well as in the early 20th century, as a cigarette flavoring. P. darienense is used medically by the Kuna people of the Panama-Colombia border region, and elsewhere it is used to intoxicate fish which then can be easily caught. Black Pepper (P. nigrum) essential oil is sometimes used in herbalism, and Long Pepper (P. longum) is similarly employed in Ayurveda, where it was an ingredient of Triphala Guggulu and (together with Black Pepper) of Trikatu pills, used for rasayana (rejuvenating and detoxifying) purposes.