Synthesis of the A/D/E-ring core compounds of maoecrystal V was achieved. The key Diels-Alder reactions between tricyclic α-methylene lactones and Kitahara-Danishefsky dienes afforded the spirocyclic core compounds in a regioselective and stereoselective manner.

Maoecrystal V is a highly oxidized and rearranged norterpenoid isolated from the Chinese herb, Isodon eriocalyx. A synthetic route for the C/D/E-ring core compound of maoecrystal V has been developed. Introduction of the C1 fragment to the D/E-ring compound was achieved by lithito dithiane attack, and the C-ring was formed by deprotective intramolecular hemiacetalization of the dithiane-alcohol precursor.

A series of serinol derivatives etherificated with a non-branched polyketide possessing a 6,8-dioxabicyclo[3.2.1]octane core was isolated from extracts of marine invertebrates, ascidian tunicates belongs to the family Didemnidae. Synthetic studies of these compounds, didemniserinolipids, cyclodidemniserinol trisulfate, and siladenoserinols, are described. The characteristics of each synthesis are in the construction of the bicyclic core from each precursor.

Olibanum (frankincense), used as a religious offering, has been one of the most valuable and respected substances since ancient times. Tea-tree, with a long history as a folk medicine for Australian aborigines, has been used in modern aromatherapy since the late 1970’s. In this paper, comparisons of olibanum and tea-tree in aromatherapy and their effects on the body and mind are discussed.

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.

Two tetranortriterpenoids with new skeletons, xylomexicanins I and J (1 and 2), were isolated during the investigation of chemical constituents from seeds of the Chinese mangrove, Xylocarpus granatum. Xylomexicanin I (1) is an unprecedented limonoid with bridged B- and C-rings. A biosynthesis pathway for 1 from xylomexicanin F is proposed.

AbstractTwo new taxane‐glycosides are isolated from the methanolic extract of the needles of T.canadensis.Their structures are evaluated by 1D and 2D NMR data analysis and high‐resolution fast atom bombardment mass spectroscopy.

Synthetic studies of enacyloxins (ENXs), a series of yellow-colored, polyene-polyol antibiotics produced by Frateuria sp. W-315, are described. The C1′-C8′ polyene fragments were prepared using successive Wittig reactions. The C9′-C15′ and C10′-C15′ fragments were constructed from ( S )-isopropylideneglyceraldehyde using Yamaguchi's nucleophilic substitution reaction of acetylide to epoxide, and/or Marshall's allenylindium mediated reaction as the key steps.

Torreyanoxane, a novel 3,4-secoglutinane triterpenoid, was isolated from the pulp of Torreya nucifera. The structure was determined on the basis of spectroscopic methods.

A novel germacrane sesquiterpenolide was isolated from the whole plant of Artemisia frigida. The structure was characterized as 1α,3α-dihydroxy-7β,11αH-germacra-4Z,10(14)-dien-12,6α-olide (1) on the basis of spectroscopic methods.

A new natural product, 8,8'-bi-3-O-methylquercetin (9), and eight known flavonoids were isolated from the flowers of Achillea millefolium. Their structures were established on the basis of spectral evidence. All the spectral data of these compounds were reassigned after interpretation of their 2D NMR spectroscopic data. Compounds 2, 5, and 7 exhibited antiproliferative activity against human breast cancer cell line MCF7WT. In addition, 2 and 5 showed antiproliferative activity against human prostatic cancer cell line PC-3, while the other compounds did not show inhibitory effects in two human tumor cell lines tested.

A novel isocomene sesquiterpenoid, 11-hydroxyisocom-2-en-5-one, was isolated from the roots of Echinops spinosissimus subsp. spinosus Greuter. The structure was characterized on the basis of NMR spectroscopic methods, including 1H–1H COSY, HMBC, HSQC, and NOESY experiments.

Arteminal, a novel eudesmane sesquiterpenoid, was isolated from the whole plant of Artemisia frigida. The structure was characterized on the basis of spectroscopic methods.

The influenza virus neuraminidase H274Y substitution is a highly prevalent amino acid substitution associated with resistance to the most heavily used influenza drug, oseltamivir. Previous structural studies suggest that the group specific 252 residue (Y252 in group 1 and T252 in group 2) might be a key factor underlying H274Y resistance. However, H274Y has only been reported in N1 subtypes, which indicates that there must be additional key residues that determine H274Y resistance. Furthermore, we found that members of NA serotype N3 also possess Y252, raising the key question as to whether or not H274Y resistance may also be possible for some group 2 NAs. Here, we demonstrate that the H274Y substitution results in mild oseltamivir resistance for N3. Comparative structural analysis of N3, N1, and their 274Y variants indicates that the interaction of residue 296 (H in N1 and nonaromatic for other serotypes) with conserved W295 is another important determinant of oseltamivir resistance.

Development of novel influenza neuraminidase inhibitors is critical for preparedness against influenza outbreaks. Knowledge of the neuraminidase enzymatic mechanism and transition-state analogue, 2-deoxy-2,3-didehydro- N -acetylneuraminic acid, contributed to the development of the first generation anti-neuraminidase drugs, zanamivir and oseltamivir. However, lack of evidence regarding influenza neuraminidase key catalytic residues has limited strategies for novel neuraminidase inhibitor design. Here, we confirm that influenza neuraminidase conserved Tyr406 is the key catalytic residue that may function as a nucleophile; thus, mechanism-based covalent inhibition of influenza neuraminidase was conceived. Crystallographic studies reveal that 2α,3ax-difluoro- N -acetylneuraminic acid forms a covalent bond with influenza neuraminidase Tyr406 and the compound was found to possess potent anti-influenza activity against both influenza A and B viruses. Our results address many unanswered questions about the influenza neuraminidase catalytic mechanism and demonstrate that covalent inhibition of influenza neuraminidase is a promising and novel strategy for the development of next-generation influenza drugs.

A new taxane, 2α,5α,10β-triacetoxy-4β,20-epoxytax-11-ene-1β,7β,9α,13α-tetraol (1), was isolated from the rooted cuttings of the Canadian yew, Taxus canadensis.

A concise synthesis of (-)-epicatechin 3-(3-O-methylgallate) (1; ECG3''Me), which is a minor constituent of tea, and (+)-catechin 3-(3-O-methylgallate) (2; CG3''Me) via condensation of equimolar amount of catechin and gallate derivatives has been achieved. The anti-inflammatory effect of the synthetic compounds on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears was examined. Compounds 1 and 2 suppressed the TPA-induced inflammation of mouse ears by 50 and 43%, respectively, at a dose of 200 microg. Their activities are stronger than those of indomethacin and glycyrrhetinic acid, the normally used anti-inflammatory agents.

A taxane with an amino-side chain on C-5 was identified for the first time from rooted cuttings of the Canadian yew, Taxus canadensis. The structure was characterized as 2α,10β,13α-triacetoxy-5α-[3'-(N-formyl-Nmethylamino)-3'-phenylpropanoyloxy]taxa-4(20),12-dien-9α-ol (1) on the basis of 1D and 2D NMR data and HR-FAB-MS analyses. The spectra revealed that in CDCl3 solution 1 was composed of two rotamers (1a and 1b) in a ratio of approximately 1:1.

We previously reported that 9-methylstreptimidone, a piperidine compound isolated from a culture filtrate of Streptomyces, induces apoptosis selectively in adult T-cell leukemia cells. It was screened for a compound that inhibits LPS-induced NF-kappaB and NO production in mouse macrophages. However, 9-methystreptimidone is poorly obtained from the producing microorganism and difficult to synthesize. Therefore, in the present research, we studied the structure-activity relationship to look for new selective inhibitors. We found that the structure of the unsaturated hydrophobic portion of 9-methylstreptimidone was essential for the inhibition of LPS-induced NO production. Among the 9-methylstreptimidone-related compounds tested, (+/-)-4,alpha-diepi-streptovitacin A inhibited NO production in macrophage-like cells as potently as 9-methylstreptimidone and without cellular toxicity. Moreover, this compound selectively induced apoptosis in adult T-cell leukemia MT-1 cells.