ABSTRACT
A general and efficient strategy for the one-pot synthesis of isothiocoumarin-1-ones has been developed via the base-promoted 6-endo-dig thioannulation of o-alkynyl oxime ethers using the cheap and readily available Na2S as the sulfur source. Mechanistic studies disclosed that the reaction proceeded through two C-S bond formations, N-O bond cleavage and the final hydrolysis of imines.
ABSTRACT
Two new tetrahydrofuran-type lignans, (-)-gentioluteol 9-O-ß-d-glucopyranoside (1), (-)-berchemol 9-O-ß-d-apiofuranosyl-(1â6)-O-ß-d-glucopyranoside (2), along with sixteen known compounds 3 - 18 were isolated from the 95% EtOH extract of the stems of Periploca forrestii. The structures of the new tetrahydrofuran-type lignans were determined by HR-ESI-MS and various NMR techniques in combination with CD method. Then, their antioxidant abilities were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, and ferric-reducing antioxidant power (FRAP) assays. Meanwhile, a similar trend was obtained in tripartite antioxidant assays, which compounds 7 - 9 and 11 exhibited potent abilities. Subsequently, the evaluation of all compounds against the α-melanocyte-stimulating hormone (α-MSH) induced melanogenesis on the B16F10 cell line, compounds 5 - 11, 15, and 16 exhibited inhibitory effects with no or weak toxicity at low concentration. Of these, compound 8 exhibited the strongest inhibition melanogenesis ability. Furthermore, Western blot analysis suggested that compound 8 could inhibit melanogenesis by suppressing the protein expression of microphthalmia-associated transcription factor (MITF) and tyrosinase.
Subject(s)
Antioxidants/chemistry , Melanins/metabolism , Periploca/chemistry , Animals , Antioxidants/isolation & purification , Antioxidants/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Circular Dichroism , Lignans/analysis , Lignans/chemistry , Lignans/pharmacology , Magnetic Resonance Spectroscopy , Melanins/antagonists & inhibitors , Melanoma, Experimental/metabolism , Melanoma, Experimental/pathology , Mice , Microphthalmia-Associated Transcription Factor/metabolism , Molecular Conformation , Periploca/metabolism , Plant Stems/chemistry , Plant Stems/metabolism , Spectrometry, Mass, Electrospray Ionization , alpha-MSH/pharmacologyABSTRACT
OBJECTIVE: To compare therapeutic effects of acupuncture combined with TDP radiation and western medicine on restless legs syndrome. METHODS: One hundred and fifty-eight cases of restless legs syndrome were randomly divided into an observation group and a control group, 79 cases in each group. The treatment group were treated with acupuncture at Shenshu (BL 23), Dachangshu (BL 25), Guanyuanshu (BL 26), Zhibian (BL 54), Taixi (KI 3), etc., and TDP radiation. The control group were treated with L-Dopa. Clinical observation was made for 30 days. RESULTS: In the observation group, 42 cases were cured, 30 cases were effective and 7 cases were ineffective with a total effective rate of 91.1%; in the control group no case was cured, 24 cases were effective and 55 cases were ineffective with a total effective rate of 30.4%, with a significant difference between the two groups in the total effective rate. CONCLUSION: Acupuncture combined with TDP radiation has a better therapeutic effect on restless legs syndrome.