ABSTRACT
Using a bioactivity-guided fractionation method, two coumarins: minumicroline acetonide (1) and epimurpaniculol senecioate (2), were isolated from the leaves of Murraya omphalocarpa Hayata (Rutaceae). Compound 1 had been previously synthesized and was now isolated from natural sources for the first time, and compound 2, possessing a negative optical rotation value, is new. The structures and their stereochemistry were fully elucidated on the basis of spectroscopic and X-ray crystallographic techniques. Both compounds 1 and 2 are active in the antiplatelet aggregation assay. Interestingly, the possible acetonide artifact 1 displayed significant antiplatelet aggregation induced not only by AA and collagen but also by platelet activating factor (PAF).
Subject(s)
Coumarins/isolation & purification , Murraya/chemistry , Plant Leaves/chemistry , Platelet Aggregation Inhibitors/isolation & purification , Animals , Arachidonic Acid/pharmacology , Blood Platelets/drug effects , Collagen/pharmacology , Coumarins/chemistry , Models, Molecular , Murraya/drug effects , Plant Leaves/drug effects , Platelet Activating Factor/pharmacology , Platelet Aggregation/drug effects , Platelet Aggregation Inhibitors/chemistry , Rabbits , Thrombin/pharmacology , X-Ray DiffractionABSTRACT
Attachment to and proliferation on the substrate are deemed important considerations when Schwann cells (SCs) are to be seeded in synthetic nerve grafts. Good attachment is a prerequisite for the SCs to survive. Fast proliferation will yield large numbers of SCs in a short time, which appears to be promising for stimulating peripheral nerve regeneration. However, surface properties are the dominating factor in influencing the interactions between cells and synthetic nerve grafts. The aim of this study was to investigate the surface effects of laminin modified PLGA and chitosan membranes after chemical method and plasma treatment. Laminin, the extracellular matrix protein, is a permissive protein for SCs adhesion used in neural regeneration. The surface properties of laminin modified membranes were assayed by BCA, FTIR and XPS analysis. Results showed that laminin was covalently bonded onto the surface of both PLGA and chitosan membranes either by chemical method or by oxygen plasma treatment. The cell affinity of the laminin modified membranes was verified by Schwann cells culturing. Our results also indicate that oxygen plasma is indeed a better method to incorporate laminin onto the surface of membrane. Laminin-modified chitosan membrane significantly increases SCs attachment and affinity for directing peripheral nerve regeneration.
Subject(s)
Biocompatible Materials/chemistry , Chitosan/chemistry , Lactic Acid/chemistry , Laminin/chemistry , Nerve Regeneration/physiology , Polyglycolic Acid/chemistry , Polymers/chemistry , Animals , Cell Adhesion , Cell Proliferation , Cells, Cultured , Female , Materials Testing , Oxygen , Polylactic Acid-Polyglycolic Acid Copolymer , Rats , Rats, Wistar , Schwann Cells/cytology , Schwann Cells/physiology , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis , Surface Properties , Tissue Engineering , X-RaysABSTRACT
Forty-one isoquinoline alkaloids were tested for antiplatelet aggregation effects. Among them, (-)-discretamine (6), protopine (7), ochotensimine (18), O-methylarmepavinemethine (23), lindoldhamine (25), isotetrandrine (26), thalicarpine (27), papaverine (28), and D-(+)- N-norarmepavine (32) exhibited significant inhibitory activity towards adenosine 5'-diphosphate (ADP)-, arachidonic acid (AA)-, collagen-, and/or platelet-activating factor (PAF)-induced platelet aggregation. The results are discussed on the basis of structure-activity relationships.
Subject(s)
Alkaloids/pharmacology , Isoquinolines/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Alkaloids/chemistry , Alkaloids/isolation & purification , Animals , Blood Platelets/drug effects , Cells, Cultured , Isoquinolines/chemistry , Isoquinolines/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plants/chemistry , Platelet Aggregation Inhibitors/chemistry , Platelet Aggregation Inhibitors/isolation & purification , RabbitsABSTRACT
Six furanogermacrane sesquiterpenes, pseudoneolinderane (1), linderalactone (2), zeylanidine (3), zeylanicine (4), deacetylzeylanidine (5), and neolitrane (6), isolated from the stems of Neolitsea parvigemma, were tested for anti-inflammatory activities. Among them, 1 and 2 showed significant inhibitory effects on superoxide anion generation by human neutrophils in response to fMLP/CB. The IC50 of 1 and 2 were found to be 3.21 and 8.48 microg/mL, respectively.
Subject(s)
Anti-Inflammatory Agents/isolation & purification , Anti-Inflammatory Agents/pharmacology , Lauraceae/chemistry , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacology , Superoxides/analysisABSTRACT
Using antiplatelet aggregation as a guide to fractionation, eight coumarins, omphalocarpinol (1), 5,7-dimethoxy-8-(3'-methyl-2'-oxobutyl)coumarin (2), murralongin, murrayanone, omphamurin (5), murragleinin, mexoticin, and murrangatin, were isolated from the leaves of Murraya omphalocarpa. Compound 1 is new, and 5 is a new enantiomer of omphamurin. The structures of these compounds were elucidated on the basis of spectroscopic techniques, and the structure of compound 1 was confirmed by X-ray crystallographic analysis. Among them, compounds 1, 2 and 5 exhibited significant antiplatelet aggregation activity.