Monarubins A-C from the Marine Shellfish-Associated Fungus Monascus ruber BB5

Three new compounds, monarubins A-C (1, 6 and 13), together with ten known compounds, including four alkaloids (2-5), two isocoumarins (7 and 8) and four polyketides (9-12), were isolated from marine shellfish-associated fungus Monascus ruber BB5. The structures were determined on the basis of the 1D and 2D NMR, MS, UV and IR data. The absolute configurations of compounds 3, 6 and 13 were determined by ECD calculations. The NMR data of compounds deoxyhydroxyaspergillic acid (3) and 2-hydroxy-6-(1-hydroxy-1-methylpropyl)-3-sec-buthylpyrazine (4) were first reported. All of the isolated compounds were evaluated for their cytotoxic activities against human nasopharyngeal carcinoma cell lines CNE1, CNE2, SUNE1 and HONE1 and hepatocellular carcinoma cell lines QGY7701 and HepG2. Monarubin B (6) displayed potent cytotoxicities against the cancer cell lines HepG2 and QGY7701 with IC₅₀ values of 1.72 and 0.71 μΜ, respectively; lunatinin (7) showed moderate cytotoxic activities against the cancer cell lines HepG2, QGY7701 and SUNE1 with the IC₅₀ values of 9.60, 7.12 and 28.12 μΜ, respectively.

Fermented Oyster Extract Prevents Ovariectomy-Induced Bone Loss and Suppresses Osteoclastogenesis

There is growing interest in bioactive substances from marine organisms for their potential use against diverse human diseases. Osteoporosis is a skeletal disorder associated with bone loss primarily occurring through enhanced osteoclast differentiation and resorption. Recently, we reported the anti-osteoclastogenic activity of fermented Pacific oyster (Crassostrea gigas) extract (FO) in vitro. The present study focused on investigating the anti-osteoporotic efficacy of FO in bone loss prevention in an experimental animal model of osteoporosis and elucidating the mechanism underlying its effects. Oral administration of FO significantly decreased ovariectomy-induced osteoclast formation and prevented bone loss, with reduced serum levels of bone turnover biomarkers including osteocalcin and C-terminal telopeptide fragment of type I collagen C-terminus (CTX). FO significantly suppressed receptor activator of nuclear factor-κB ligand (RANKL)-induced differentiation of bone marrow-derived macrophages (BMMs) into osteoclasts and attenuated the induction of osteoclast-specific genes required for osteoclastogenesis and bone resorption. Furthermore, FO inhibited RANKL-mediated IκBα and p65 phosphorylation in BMMs. Taken together, these results demonstrate that FO effectively suppresses osteoclastogenesis in vivo and in vitro, and that FO can be considered as a potential therapeutic option for the treatment of osteoporosis and osteoclast-mediated skeletal diseases.

Extraction, structural characterization, and thermal and biomedical properties of sulfated polysaccharides from razor clam Solen marginatus

In this study, the antioxidant, antibacterial and anticoagulant activities of sulfated polysaccharides extracted from Solen marginatus flesh were investigated via physicochemical characterization of the crude polysaccharide SM-CP and its deproteinized fraction (SM-DP); their total sugar contents were 47.15% and 66.01%. The results obtained via molecular weight evaluation showed that SM-CP mainly had a high molecular weight (1075 kDa), whereas SM-DP had a lower molecular weight (almost 237.9 kDa); in addition, thermal analysis (differential scanning calorimetry and thermogravimetry) was conducted; the results indicated that SM-CP was thermally more stable as its degradation temperature was 307 °C, whereas SM-DP was thermally less stable, with the degradation temperature of 288 °C. Moreover, the results obtained via the investigation of biological properties revealed that the extracted polysaccharides exhibited strong antioxidant and anticoagulant activities. Subsequently, SM-CP was fractionated using the DEAE-cellulose column. The peak (FII) eluted at high NaCl concentrations indicated highest anticoagulant activity as designated by the prolongation of the activated partial thromboplastin time (over 120 s), prothrombin time (28 s) and low level of fibrinogen (0.7 g l⁻¹). The overall data demonstrated the significant therapeutic potential of the polysaccharides extracted from razor clam flesh.

In this study, some biological activities of sulfated polysaccharides extracted from Solen marginatus flesh were investigated via physicochemical characterization of the crude polysaccharide SM-CP and its deproteinized fraction SM-DP.