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  • Author: Yu-Cheng Gu x
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A new taxoid metabolite with an unusual double bond between C-13 and C-14 was isolated from the methanol extract of the hard wood of Taxus cuspidata. The structure was established as 2α,5α,7β ,9α,10β ,13β -hexaacetoxy-11β -hydroxyl-19β -benzoxytaxa-4(20),13-dien- 12,16-epoxide (1), named 5,13-diacetyltaxinine M-13-enol, on the basis of spectral analysis including 1H NMR, 13C NMR, HMQC, HMBC, NOESY and confirmed by HR-FAB-MS.

Abstract

Structural modifications were performed on isoalantolactone in an effort to find compounds with potential anticancer activity. Seven previously unknown adducts of active methylene compounds with isoalantolactone were synthesized by the Michael reaction. Moreover, four derivatives of aryl-substituted isoalantolactone were prepared by the Heck reaction. All synthetic products were evaluated for toxic activities against three different hepatoma cell lines, Bel-7402, SMMC-7721, and Hep G2. Products prepared through the Heck reaction and 3a,b show potential antiproliferative activity against the Hep G2 cell.

Abstract

The genus Neolitsea (Lauraceae) contains over 85 species distributed around the world. These plants have been found to be rich in sesquiterpenes, triterpenes, steroids, and alkaloids. This review summarizes the phytochemical progress and list of all the constituents isolated from the genus Neolitsea over the past few decades. Some biological activities of compounds isolated from this genus are also included.

Abstract

Ordered mesoporous U3O8 has been synthesized by a nanocasting route using mesoporous silica (KIT-6 and SBA-15) as templates and characterized by using XRD, SEM and nitrogen adsorption/desorption techniques.

Diabietane ether (1), a new abietane dimer connected by an ether linkage, and two known abietane diterpenoids (2 and 3) were isolated from the needles of Taxus cuspidata.

Sinenxan H [2α,14β -diacetoxytaxa-4(20),11-diene-5α, 10β -diol, 1] was isolated from the heartwood of Taxus cuspidata, for the first time from natural sources. Compound 1 was found to be readily converted into 2α-acetoxytaxa-4(20),10,12(18),13-tetraen-5α-ol (2), the first example of a taxane with 10,11- and/or 13,14-double bond(s) and a conjugated triene system, in CDCl3.

Abstract

Valproic acid (VPA) has been suggested to be a histone deacetylase inhibitor (HDACI). Our present study revealed that VPA at 1 mm, which had no effect on cell proliferation, can significantly increase the sensitivity of non-small cell lung cancer (NSCLC) cells to cisplatin (DDP). VPA treatment markedly decreased the mRNA and protein levels of ABCA1, while had no significant effect on ABCA3, ABCA7 or ABCB10. Luciferase reporter assays showed that VPA can decrease the ABCA1 promoter activity in both A549 and H358 cells. VPA treatment also decreased the phosphorylation of SP1, which can bind to −100 and −166 bp in the promoter of ABCA1. While the phosphorylation of c-Fos and c-Jun were not changed in VPA treated NSCLC cells. Over expression of HDAC2 attenuated VPA induced down regulation of ABCA1 mRNA expression and promoter activities. Over expression of HDAC2 also attenuated VPA induced DDP sensitivity of NSCLC cells. These data revealed that VPA can increase the DDP sensitivity of NSCLC cells via down regulation of ABCA1 through HDAC2/SP1 signals. It suggested that combination of VPA and anticancer drugs such as DDP might be great helpful for treatment of NSCLC patients.

Abstract

The genus Ajuga, a member of the Lamiaceae family, is comprised of more than 300 species of annual and perennial herbaceous flowering plants mainly distributed throughout the temperate regions of Asia, Europe, Australia, North America and Africa. These plants are used as folk medicines effective for rheumatic fevers, dysentery, malaria, hypertension, diabetes and gastrointestinal disorders, as well as anthelmintic, astringent, febrifuge diuretic, antifungal and anti-inflammatory agents. A variety of constituents has been isolated from these plants. This review summarizes the phytochemical progress of the genus Ajuga and lists the compounds isolated up to 2014.

Abstract

A novel 6/12-membered bicyclic taxane with a 13,17-ether bridge, named canataxpyran A, was isolated from the needles of Taxus canadensis. The structures were characterized as 7β,9,10β,20-tetracetoxy-13β,17-epoxy-3,8-secotaxa-3E,8E,11-triene-2α,5α-diol (designated as canataxpyran A, 1). This bicyclic taxane gradually decomposed in CDCl3to give the corresponding enones, 10β,20-diacetoxy-13β,17-epoxy-4α,5α-dihydroxy-3,8-secotaxa-2E,7E,11-trien-9-one (canataxpyran B, 2) and 5α,10β,20-triacetoxy-13β,17-epoxy-4α-hydroxy- 3,8-secotaxa-2E,7E,11-trien-9-one (canataxpyran C, 3). Compound 1 is the first example of a natural 3,8-secotaxane with 13,17-oxygen bridge.