Preparation, structural characteristics and antioxidant activity of polysaccharide and its metal chelates from the peel of Dioscorea oppositifolia L.

Two metal chelates of Dioscorea oppositifolia L. peel polysaccharides (DTP) were prepared: iron chelate (DTP-Fe) and zinc chelate (DTP-Zn). The physicochemical properties of the polysaccharide and its metal chelates were assessed by UV-Vis absorption spectroscopy, Fourier-transform infra-red spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Antioxidant activities were evaluated by DPPH, ABTS + and hydroxyl radical scavenging assays. According to ICP-MS, the iron content of DTP-Fe was 9.47%, while the zinc content of DTP-Zn was 4.02%. The antioxidant capacity of DTP-Fe increased with the increase of concentration, and its overall activity was higher than that of DTP and DTP-Zn. This polysaccharide-iron chelate can be developed and utilised as an antioxidant and multifunctional iron supplement. DTP-Zn showed the potential to be a natural antioxidant and zinc supplement food.

Structure and Bioactivities of a Novel Polysaccharide Extracted From Dendrobium huoshanense by Subcritical Water.

In this study, the polysaccharide was extracted by subcritical water from Dendrobium huoshanense. A novel polysaccharide (DHPs-1) was obtained through several purification steps and its structure and bioactivity were investigated. Structural analysis indicated that the weight-average molecular weight of DHPs-1 was 5.0 × 104 Da and it was mainly composed of glucose (65.04%), mannose (14.23%), galactose (8.17%), galacturonic acid (6.41%), rhamnose (2.34%), and xylose (1.25%). 1,4-Glcp, and 1,4,6-Galp were existed in the backbone of DHPs-1. The residues of 1,3,4-Galp, 1,4-Manp, 1,4-Galp, and 1,3,4,6-Galp could be in the backbone or the side chains with the non-reducing terminal of α-Manp. Bioactivity tests indicated that DHPs-1 had immunomodulatory activity in that it significantly enhanced transcript levels of cytokines [Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1ß (IL-1ß), and Interleukin-10 (IL-10)]. DPPH and hydroxyl radical scavenging tests showed that it had good antioxidant activity. These results reveal that DHPs-1 could be developed as a safe immunomodulatory agent and antioxidant for pharmacological or functional food applications.

Prenylated Indole Diterpene Alkaloids from a Mine-Soil-Derived Tolypocladium sp.

Ten new prenylated indole diterpene alkaloids, tolypocladin A-J (1-10), including four chlorinated metabolites, have been isolated from a culture of a mine-soil-derived fungus, Tolypocladium sp. XL115. The structures and absolute configurations of 1-10 were determined by spectroscopic analysis, ECD calculations, and comparison with known compounds. Compounds 1 and 8 displayed significant antimicrobial activities. In addition, compound 1 also showed weak cytotoxic activity against all tested human cancer cell lines and suppressed the growth and viability of the patient-derived HCC cells T1224.

Egg white, a favourable solvent to extract the active ingredient of Mylabris phalerata.

To characterize the role of hen eggs used for analyzing the insect Mylabris phalerata a traditional Chinese medicine for curing liver cancer, egg white was separated from the whole egg and added to M. phalerata. The volatile compounds found in egg white when added to M. phalerata and therefore in M. phalerata itself were analyzed by GC. Cantharidin was detected both in egg white added to M. phalerata and M. phalerata itself. Egg white can be used as a favourable solvent for extracting the active ingredient of M. phalerata.

[Chemical study of nucleosides on Cordyceps militaris].

OBJECTIVE: To investigate the nucleosides of Cordyceps militaris. METHODS: The primary extract technique of nucleosides from Cordyceps militaris was founded, the nucleosides were isolated by chromatography. RESULTS: Four compounds were isolated from the mycelium of Cordyceps militaris. They were identified as uridine (1), adenosine (2), guanosine (3) and p-tyrosine (4), respectively. CONCLUSION: Compounds 1, 2 and 3 are the main nucleosides in Cordyceps militaris.

[Chemical study on fruiting bodies of Boletus vioaceo-fuscus].

OBJECTIVE: To investigate the chemical constituents of Boletus vioaceo-fuscus. METHOD: The compounds were isolated with column chromatography. The structures were determined by spectroscopic techniques. RESULT: Six compounds were isolated from the fruiting bodies of Boletus vioaceo-fiuscus. They were identified as ergosta-5, 7, 22-triene-3beta-ol (1), dihydrofuran-2, 5-dione (2), (22E, 24R)-5alpha, 6alpha-epoxyergosta-8, 22-diene-3beta, 7alpha-diol (3), (22E, 24R)-5alpha, 6alpha-epoxyergosta-8 (14), 22-diene-3beta, 7alphadiol (4), cerebroside B (5) and adenosine (6), respectively. CONCLUSION: All the Compounds were obtained from the fruiting bodies of Boletus vioaceo-fiscus for the first time.

Trametes versatillis, a fungus highly producing eburicoic acid.

Eburicoic acid was produced and isolated from the cultured mycelia of the fungus, Trametes versatillis. The weight rate of eburicoic acid in the dry weight of cultured mycelia of Trametes versatillis was about to 1%. Trametes versatillis can be expected as an important bioresource to supply eburicoic acid for its industrial exploitation.

Monitoring of BHT-quinone and BHT-CHO in the gas of capsules of Asclepias physocarpa.

Three volatile components, namely benzoic acid ethyl ester (1), 2,6-di-tert-butyl-p-benzoquinone (BHT-quinone) (2), and 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO) (3), were detected from the gas in the capsules of Asclepias physocarpa by means of GC/MS analysis. BHT-quinone and BHT-CHO as organic pollutants are the degradation products of the antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT). Ground water, lake water and/or rain water are a source of BHT metabolites in the plant Asclepias physocarpa.

A new bitter diterpenoid from Sarcodon scabrosus.

The new cyathane-type diterpenoid sarcodonin I was isolated from the fruiting bodies of the basidiomycete Sarcodon scabrosus. Its structure was determined on the basis of spectroscopic means, including 2D-NMR (HMBC, HMQC, ROESY, 1H, 1H-COSY).