Search results for "Piper"

Secondary metabolites from polar fractions of Piper umbellatum.

2012

Seven known secondary metabolites were isolated from the methanol extract of the branches of Piper umbellatum. The identification of these compounds was mainly achieved by 2D NMR spectroscopic techniques and FAB-MS. Among them, the known cepharadiones A and B can be considered as chemotaxonomic markers of the genus Piper.

Prevention of the acute neurotoxic effects of phenytoin on rat peripheral nerve by H7, an inhibitor of protein kinase C.

1992

Abstract The neurotoxic effects of a single dose of phenytoin (150 mg/kg body weight) alone or 30 min after H7 (a protein kinase C inhibitor) injection (20 mg/kg body weight) were investigated in terms of peripheral neuromuscular function and Na + ,K + -ATPase activity of the sciatic nerve. This intraperitoneal injection of phenytoin induced complete blockade of muscle action potentials in the dorsal segmental muscles of the rat tail evoked by electric stimulation of the caudal nerve and a 40% decrease in the Na + ,K + -ATPase activity of the rat sciatic nerve when compared with control values, measured as the difference between total and ouabain-insensitive ATPase activity. Prior administr…

Photocatalytic synthesis of piperonal in aqueous TiO2 suspensions

2013

Glass-Forming Nonsymmetric DWKdyes with 5,5,5-Triphenylpentyl and Piparazine Moieties for Lightamplification Studies

2018

This work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/1/16/035). Financial support provided by A. Riekstins SIA “Mikrotīkls” donation, administered by the University of Latvia is greatly appreciated. There are no conflicts of interest to declare.

X-ray Crystal Structure and Hirshfeld Analysis of Gem-Aminals-Based Morpholine, Pyrrolidine, and Piperidine Moieties

2020

The gem-aminals of 1,2-dimorpholinoethane (1) and 1-morpholino-3-morpholinium bromide propane (2) were synthesized by reaction of two molar ratio of morpholine with the halogenating agents in the presence of basic condition (K2CO3) in acetone at room temperature (RT) overnight. The structures of the centro-symmetric compound 1 and the morpholinium salt derivative 2 were assigned unambiguous by single crystal X-ray diffraction analysis and compared with the 1,2-di(pyrrolidin-1-yl)ethane 3 and 1,2-di(piperidin-1-yl)ethane 4. The 1,2-dimorpholinoethane molecule has a center of symmetry at the midpoint of the C-C bond of the ethyl moiety leading to two equivalent halves. It crystallized in mono…

Effects of carboxyamidotriazole on in vitro models of imatinib-resistant chronic myeloid leukemia.

2008

Although imatinib mesylate (IM) has revolutionized the treatment of chronic myeloid leukemia (CML), some patients develop resistance with progression of leukemia. Alternative or additional targeting of signaling pathways deregulated in bcr-abl-driven CML cells may provide a feasible option for improving clinical response and overcoming resistance. In this study, we show that carboxyamidotriazole (CAI), an orally bioavailable calcium influx and signal transduction inhibitor, is equally effective in inhibiting the proliferation and bcr-abl dependent- and independent-signaling pathways in imatinib-resistant CML cells. CAI inhibits phosphorylation of cellular proteins including STAT5 and CrkL a…

Bioactivity of fractions and constituents of Piper capense fruits towards a broad panel of cancer cells.

2020

Abstract Ethnopharmacological relevance Piper capense is a medicinal spice whose fruits are traditionally used as aqueous decoction to heal several ailments such as trypanosomiasis, helminthic infections, and cancer. Aim of the study. (1) To perform phytochemical investigation of the methanol extract of Piper capense; (2) to evaluate the cytotoxicity of botanicals (PCF, fractions PCFa-e), isolated phytochemicals on a broad panel of animal and human cancer cell lines; (3) to evaluate the induction of apoptosis of the most active samples. Material and methods Resazurin reduction assay (RRA) was used to determine the cytotoxicity of the studied samples. Cell cycle distribution (PI staining), a…

Antileishmanial Activity of the Genus Piper: A Systematic Review

2021

Background: Leishmaniases are anthropozoonotic vector-borne diseases, caused by the protozoan Leishmania spp. These diseases have significant morbidity and mortality worldwide and, as there are currently no vaccines available for their treatment, chemotherapy remains the mainstay for anti-leishmanial therapeutics. However, the severe side effects, reduced bioavailability, high cost and chemoresistance, amongst other problems, limit the use of available drugs. In recent years, natural compounds have shown promise as anti-leishmanial agents, especially those extracted from medicinal plants. The genus Piper has been used in traditional medicine and widely explored for its biological properties…

Synthesis of two Conformationally Restricted Piperazine Scaffolds for Combinatorial Chemistry

2004

Piperazines are widely used as central elements in the construction of bioactive molecules. Herein, the short synthesis of two chiral 2,6-bridged piperazines possessing orthogonally stable protecting groups from readily available starting materials is described. It is suggested that these molecules may be used as conformationally restricted scaffolds for the combinatorial synthesis of drug-like compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Esterase inhibition by synergists in the western flower thrips Frankliniella occidentalis.

2010

BACKGROUND: Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is among the most important crop pests in the south-eastern region of Spain. Its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. Use of synergists to inhibit the enzymes involved in insecticide detoxification is widely used to determine their responsibility for insecticide resistance. However, they do not always act as intended or expected, and caution must be exercised when interpreting synergist results. RESULTS: Laboratory-selected strains of WFT were used to analyse the effects of the synergists piperonyl butoxide …