Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Toxins (Basel) ; 16(3)2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38535829

RESUMO

Alkaloids play an essential role in protecting plants against herbivores. Humans can also benefit from the pharmacological effects of these compounds. Plants produce an immense variety of structurally different alkaloids, including quinolizidine alkaloids, a group of bi-, tri-, and tetracyclic compounds produced by Lupinus species. Various lupin species produce different alkaloid profiles. To study the composition of quinolizidine alkaloids in lupin seeds, we collected 31 populations of two wild species native to Israel, L. pilosus and L. palaestinus, and analyzed their quinolizidine alkaloid contents. Our goal was to study the alkaloid profiles of these two wild species to better understand the challenges and prospective uses of wild lupins. We compared their profiles with those of other commercial and wild lupin species. To this end, a straightforward method for extracting alkaloids from seeds and determining the quinolizidine alkaloid profile by LC-MS/MS was developed and validated in-house. For the quantification of quinolizidine alkaloids, 15 analytical reference standards were used. We used GC-MS to verify and cross-reference the identity of certain alkaloids for which no analytical standards were available. The results enabled further exploration of quinolizidine alkaloid biosynthesis. We reviewed and re-analyzed the suggested quinolizidine alkaloid biosynthesis pathway, including the relationship between the amino acid precursor l-lysine and the different quinolizidine alkaloids occurring in seeds of lupin species. Revealing alkaloid compositions and highlighting some aspects of their formation pathway are important steps in evaluating the use of wild lupins as a novel legume crop.


Assuntos
Lupinus , Alcaloides Quinolizidínicos , Humanos , Cromatografia Líquida , Espectrometria de Massas em Tandem , Sementes
2.
Eur J Pharm Sci ; 132: 118-120, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30851400

RESUMO

Cannabis sativa is widely used for medical purposes. However, to date, aroma, popular strain name or the content of two phytocannabinoids-Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are mostly considered for therapeutic activity. This is despite the hundreds of compounds in this plant and their potential synergistic interactions in mixtures. New, specific and effective cannabis-based drugs must be developed to achieve adequate medical standards for the use of cannabis. To do this, the comprehensive molecular profile of cannabis-based drugs must be defined, and mixtures of compounds should be tested for superior therapeutic activity due to synergistic effects compared to individually isolated cannabis compounds. The biological pathways targeted by these new drugs should also be characterized more accurately. For drug development and design, absorption, distribution, metabolism and elimination versus toxicity (ADME/Tox) must be characterized, and therapeutic doses identified. Promoting the quality and therapeutic activity of herbal or synthetic cannabis products to pharma grade is a pressing need worldwide.


Assuntos
Canabidiol/farmacologia , Cannabis/química , Dronabinol/farmacologia , Descoberta de Drogas/métodos , Descoberta de Drogas/tendências , Maconha Medicinal/farmacologia , Canabidiol/isolamento & purificação , Dronabinol/isolamento & purificação , Maconha Medicinal/isolamento & purificação
3.
Cannabis Cannabinoid Res ; 3(1): 120-135, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29992185

RESUMO

Introduction: Colorectal cancer remains the third most common cancer diagnosis and fourth leading cause of cancer-related mortality worldwide. Purified cannabinoids have been reported to prevent proliferation, metastasis, and induce apoptosis in a variety of cancer cell types. However, the active compounds from Cannabis sativa flowers and their interactions remain elusive. Research Aim: This study was aimed to specify the cytotoxic effect of C. sativa-derived extracts on colon cancer cells and adenomatous polyps by identification of active compound(s) and characterization of their interaction. Materials and Methods: Ethanol extracts of C. sativa were analyzed by high-performance liquid chromatography and gas chromatograph/mass spectrometry and their cytotoxic activity was determined using alamarBlue-based assay (Resazurin) and tetrazolium dye-based assay (XTT) on cancer and normal colon cell lines and on dysplastic adenomatous polyp cells. Annexin V Assay and fluorescence-activated cell sorting (FACS) were used to determine apoptosis and cell cycle, and RNA sequencing was used to determine gene expression. Results: The unheated cannabis extracts (C2F), fraction 7 (F7), and fraction 3 (F3) had cytotoxic activity on colon cancer cells, but reduced activity on normal colon cell lines. Moreover, synergistic interaction was found between F7 and F3 and the latter contains mainly cannabigerolic acid. The F7 and F7+F3 cytotoxic activity involved cell apoptosis and cell cycle arrest in S or G0/G1 phases, respectively. RNA profiling identified 2283 differentially expressed genes in F7+F3 treatment, among them genes related to the Wnt signaling pathway and apoptosis-related genes. Moreover, F7, F3, and F7+F3 treatments induced cell death of polyp cells. Conclusions:C. sativa compounds interact synergistically for cytotoxic activity against colon cancer cells and induce cell cycle arrest, apoptotic cell death, and distinct gene expression. F3, F7, and F7+F3 are also active on adenomatous polyps, suggesting possible future therapeutic value.

4.
Appl Spectrosc ; 65(1): 43-51, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21211153

RESUMO

Bulk thermal alterations to chlorite schist occurring at temperatures above 450 °C are traditionally studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, or thermogravimetric analysis (TGA), but lower temperature changes that lead to structural and chemical alteration, including changes in oxidation state that are not followed by a crystalline modification, are not detectable using these techniques. In this paper we present the results of the first study to examine the application of fiber-optic reflection spectroscopy (FORS) for the detection and quantification of low-temperature thermal alterations in chlorite schist. Such changes have been observed during research on the thermal behavior of medieval (12th-13th centuries AD) chlorite cooking pots from the archaeological site of Merv, Turkmenistan. FORS was used to investigate these changes, testing the archaeological samples against a model data set of experimental reference specimens. The results demonstrate the potential of FORS for tracking low-temperature thermal alterations and offer the opportunity to examine temperatures attained by ancient chlorite vessels during their past use in cooking activities.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...