Structural characterization and intestinal protection activity of polysaccharides from Sea buckthorn (Hippophae rhamnoides L.) berries.

The sea buckthorn (Hippophae rhamnoides L.) berries are rich in various bioactive components and widely used as fruit and traditional medicine. In this study, a novel heteropolysaccharide fraction (SP0.1-1) was isolated from Sea buckthorn berries. SP0.1-1 is composed of mannose, glucose, galactose, and arabinose in the molar ratio of 1:2.3:1.9:11.2 with a core structure containing 1,4-linked-α-d-Glcp, 1,4,6-linked-α-d-Glcp and 1,4-linked-α-d-Manp residues as the backbone. And the side-chains comprised of 1,3,5-linked-α-l-Araf, 1,5-linked-α-l-Araf, terminal α-Araf and 1,4-linked-ß-d-Galp. Furthermore, a diet supplemented with SP0.1-1 extended the mean lifespan, enhanced antioxidant enzyme (superoxide dismutase, SOD; glutathione peroxidase, GSH-Px; and catalase, CAT) activities, and decreased the malondialdehyde (MDA) level and hydrogen peroxide (H2O2)-induced mortality rate in fruit flies (Drosophila melanogaster). To summarize, the study's findings will provide evidence for the development of sea buckthorn polysaccharide products.

Structure and immunostimulating activity of a galactofuranose-rich polysaccharide from the bamboo parasite medicinal fungus Shiraia bambusicola.

ETHNOPHARMACOLOGICAL RELEVANCE: Shiraia bambusicola is a parasitic fungus on the twigs of bamboos. Its relatively large stroma has high medicinal value and can treat a variety of diseases such as rheumatoid arthritis, cold stomach pain, sciatica, injuries, chronic bronchitis, and infantile. It is widely distributed in many provinces in Southern China and also is also found in Japan. AIM OF THE STUDY: Medicinal fungi were important resources for bioactive polysaccharides. To explore bioactive polysaccharides from Shiraia bambusicola, a heteropolysaccharide SB2-1 was purified and obtained from S. bambusicola and its immunostimulating activity was researched. MATERIALS AND METHODS: The polysaccharide from S. bambusicola was extracted and purified using enzyme assisted extraction, ethanol precipitation, anion-exchange and size-exclusion chromatography. Molecular weight of polysaccharide was estimated by high performance gel permeation chromatography. Monosaccharide compositions were determined by high performance liquid chromatography after pre-column derivatization and UV detection. Structure information was elucidated by IR spectrum, GC-MS analysis after methylation and gradual acid hydrolysis of the polysaccharide. The RAW264.7 cells were used to study the immunostimulating activity in vitro. RESULTS: Physicochemical and structural analyses showed that SB2-1 was a neutral heteropolysaccharide with molecular weight at 22.2 kDa and consisted of glucose, galactose and mannose at a ratio of 2.0:1.5:1.0. The structure of SB2-1 was a branched polysaccharides composed of a mannan core and side chains consisted of glucose and galactose. The mannan core was composed of (1→2)-Manp as the main chain. Glucose with (1→4)-D-Glcp, (1→2)-D-Glcp and (1→6)-D-Glcp at different degrees of polymerization were linked at C-6 and C-3 of the (1→2)-Manp as the side chains. The galactose with the linages of (1→6)-D-Galf, →2)-D-Galf(1→ and terminal D-Galf(1→ also existed in the side chain. The study on the immunostimulating activities of SB2-1 and its core structure P-2 were investigated on RAW264.7 macrophages. The results showed that SB2-1 could activate RAW264.7 macrophage and significantly improve its phagocytic ability by neutral red uptake experiment. Meanwhile, SB2-1 increased significantly higher inducible nitric oxide synthase (iNOS) production and the productions of IL-1, IL-6, IL-12 and TNF-α. The effect of SB2-1 was better than its core structure P-2 produced by gradual acid hydrolysis, which meant the side chains played an important role in the immunostimulating activities. CONCLUSIONS: The investigation demonstrated that the galactofuranose-containing mannogalactoglucan was characteristic polysaccharides in S. bambusicola and could enhance the activation of macrophages.

Bioactive Exopolysaccharides Reveal Camellia oleifera Infected by the Fungus Exobasidium gracile Could Have a Functional Use.

Camellia oleifera is an important Chinese commercial crop. Camellia oleifera can display abnormal leaves due to infection by the parasitic fungus Exobasidium gracile. Exobasidium gracile was isolated from infected leaves and used in fermentation, and exopolysaccharides EP0-1 and EP0.5-1 were purified from the fermentation broth. EP0-1 was an alkaline polysaccharide consisting mainly of the linkages α-d-Manp(1→, →2)-α-d-Manp(1→ and →6)-α-d-Manp(1→, →3)-α-d-Glcp(1→ and→4)-α-d-Glcp(1→, terminal ß-d-Galf, (1→5)-ß-d-Galf, and terminal ß-D-GlcN(1→. EP0.5-1 was an acidic galactofuranose-containing polysaccharide. It contained the linkages of α-d-Manp(1→, →2)-α-d-Manp(1→, →6)-α-d-Manp(1→,→2, 6)-α-d-Manp(1→, →4)-α-d-Glcp(1→, and →4)-α-d-GlcUA(1→. Galactofuranose linkages were composed of terminal ß-d-Galf, (1→6)-ß-d-Galf and (1→2)-ß-d-Galf. Exobasidium gracile exopolysaccharides displayed significant immunoregulatory activity by activating macrophages. This research indicates that infected leaves from Camellia oleifera including the exopolysaccharides produced by the parasitic fungus Exobasidium gracile by are worth further investigation as a functional product.

Bioactive Pimarane Diterpenes from the Arctic Fungus Eutypella sp. D-1.

Two new pimarane diterpenes, libertellenone M (1) and libertellenone N (2), together with five known compounds were isolated from the culture extract of Eutypella sp. D-1 derived from high-latitude soil of the Arctic. The structures of these compounds were determined by spectroscopic data as well as experimental and calculated electronic circular dichroism (ECD) analysis. Antimicrobial and cytotoxic activities of the isolated compounds were evaluated. Compound 3 exhibited weak antibacterial activity against Escherichia coli, Bacillus subtilis, and Vibrio vulnificus, each with MIC values of 16 µg/mL. Compounds 2 and 3 showed moderate cytotoxic activity against K562 and MCF-7 cell lines with IC50 values of 7.67 and 9.57 µm, respectively.