10 resultados
Four new stilbene derivatives, hypargystilbenes B-E (1-4), together with seven known compounds (5-11), were isolated from the stems of Artocarpus nanchuanensis S.S. Chang. Their structures were elucidated on the basis of spectral data. Hypargystilbene B, hypargystilbene D, and hypargystilbene E
The effect of chemical modification on an anti T-like lectin, artocarpin isolated from Artocarpus lakoocha seeds was investigated in order to identify the type of amino acids involved in its agglutinating activity. Modification of carboxyl groups, arginine and lysine residues, did not affect the
In an effort to identify agents from natural products that inhibit protein tyrosine phosphatase 1B (PTP1B), 5 new prenylated stilbenes, (±)-styrastilbene A (1: ), styrastilbene B (2: ), and (±)-styrastilbenes C - E (3, 4: , and 7: ), along with 4 known structurally related compounds (5, 6, 8: , and
Mast cells are connective tissue resident cells with morphological and functional characteristics that contribute to their role in allergic and inflammatory processes, host defense and maintenance of tissue homeostasis. Mast cell activation results in the release of pro-inflammatory mediators which
It has been well established that CD45 is a key receptor-type protein tyrosine phosphatase (PTPase) regulating Src-family protein tyrosine kinase (Src-PTK) in T and B lymphocytes. However, precisely how CD45 exerts its effect in these lymphocytes remains controversial. We recently reported that
Jacalin, an alpha-O-glycoside of the disaccharide Thomsen-Friedenreich antigen (galactose beta1-3 N-acetylgalactosamine, T-antigen)-specific lectin from jackfruit seeds, has been shown to induce mitogenic responses and to block infection by HIV-1 in CD4+ T lymphocytes. The molecular mechanism
The hemagglutinin from the seeds of Artocarpus hirsuta was purified to homogeneity by ion-exchange chromatography on DEAE-cellulose and CM-sephadex. The native protein of molecular mass 60,000 (gel filtration) is made up of two pairs of unidentical subunits, alpha and beta with molecular masses of
The Maclura pomifera agglutinin (MPA) was purified by affinity chromatography from a seed extract and its properties were compared with those of the Artocarpus integrifolia lectin, jacalin. Reverse-phase high-performance liquid chromatography showed both proteins had multiple forms of a small
The KM+ lectin exhibits a novel and unusual circular dichroism (CD) spectrum that could be explained by a high proline content that would be inducing deformation of the beta-structure and/or unusual turns. KM+ was shown to be a very rigid lectin, which was very stable under a broad variety of
The recognition of cell surface glycans by lectins may be critical for the innate and adaptive immune responses. ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus, activates antigen-presenting cells by recognizing TLR2 N-glycans and induces Th1 immunity. We recently demonstrated that