Bysspectin A, an unusual octaketide dimer and the precursor derivatives from the endophytic fungus Byssochlamys spectabilis IMM0002 and their biological activities.

Bysspectin A (1), a polyketide-derived octaketide dimer with a novel carbon skeleton, and two new precursor derivatives, bysspectins B and C (2 and 3), were obtained from an organic extract of the endophytic fungus Byssochlamys spectabilis that had been isolated from a leaf tissue of the traditional Chinese medicinal plant Edgeworthia chrysantha, together with a known octaketide, paecilocin A (4). Their structures were determined by HRMS, 1D and 2D NMR spectroscopic analysis. A plausible route for their biosynthetic pathway is proposed. Compounds 1-3 were tested for their antimicrobial activities. Only compound 3 was weakly active against Escherichia coli and Staphyloccocus aureus with MIC values of 32 and 64 µg/mL, respectively. Further, the inhibitory effects on human carboxylesterases (hCE1, hCE2) of compounds 1 and 4 were evaluated. The results demonstrated that bysspectin A (1) was a novel and highly selective inhibitor against hCE2 with the IC50 value of 2.01 µM. Docking simulation also demonstrated that active compound 1 created interaction with the Ser-288 (the catalytic amino-acid in the catalytic cavity) of hCE2 via hydrogen bonding, revealing its highly selective inhibition toward hCE2.

Neuroprotective effect of piperine on primarily cultured hippocampal neurons.

It was previously reported that piperine (PIP) significantly blocks convulsions induced by intracerebroventricular injection of threshold doses of kainate, but had no or only slight effects on convulsions induced by L-glutamate, N-methyl-D-aspartate and guanidinosuccinate. In traditional Chinese medicine, black pepper has been used for epileptic treatment; however, the exact mechanism is still unclear. We reported here in that appropriate concentration of PIP effectively inhibites the synchronized oscillation of intracellular calcium in rat hippocampal neuronal networks and represses spontaneous synaptic activities in terms of spontaneous synaptic currents (SSC) and spontaneous excitatory postsynaptic currents (sEPSC). Moreover, pretreatment with PIP expects protective effect on glutamate-induced decrease of cell viability and apoptosis of hippocampal neurons. These data suggest that the neuroprotective effects of PIP might be associated with suppression of synchronization of neuronal networks, presynaptic glutamic acid release, and Ca(2+) overloading.

[The clinical observation on acupuncture at Xuanzhong (GB 39) and Ashi points for treatment of orthopedic postoperative pain].

OBJECTIVE: To compare the therapeutic effects between acupuncture and Bezoxazocine injection in treatment of orthopedic postoperative pain. METHODS: Sixty patients were randomly divided into an acupuncture group and a medication group, 30 cases in each group. The patients in the acupuncture group were treated by acupuncture at Xuanzhong (GB 39) as main point and Ashi points for 30 minutes; the medication group were treated by intramuscular injection of Bezoxazocine injection, 20 mg once, three times per day. Then the pain changes within 48 hours were observed and recorded in two groups. RESULTS: The good rates at 24 hours and 48 hours were 89.2% and 100.0% in the acupuncture group and 81.4% and 96.3% in the medication group, respectively. The analgesic effect of acupuncture was better than that of Bezoxazocine injection (P < 0.05). CONCLUSION: Analgesic effect of acupuncture at Xuanzhong (GB 39) on orthopedic postoperative pain and Ashi points is better than Bezoxazocine injection.