The title compound, C(27)H(34)O(5), a beyerane-type diterpenoid prepared by peroxidation and benzoyl-ation of isosteviol, contains a fused six-membered ring system. The O atoms of the benzoic ester and the lactone are disordered with occupancy ratios of 0.6 (4):0.4 (4) and 0.6 (2):0.4 (2), respectively. Three cyclo-hexane rings have chair conformations, whereas the remaining lactone ring adopts...

The systematic investigation on the roots of Taxus wallichiana has resulted in the isolation of nine taxoids-taxol 1 baccatin III 2, baccatin IV 3, taxusin 4, a C-14 oxygenated taxoid 5, I~-hydroxybaccatin 16, pentaacetoxy taxadiene 7, a dibenzoylated rearranged taxoid 8, 7-xylosyl-1 O-deacetyl-taxol C 9 and three phenolic compounds (-) seco-isolariciresinol 11, taxiresinol 12 and isotaxiresino...

Brønsted acid promoted nucleophilation of propargylic alcohols during the Meyer-Schuster rearrangement (M-S) has been introduced. A novel concept of reverse polarization of the M-S intermediate allenyl cation has been realized by employing a cis-enoate assisted strategy. This idea is well demonstrated by the metal free synthesis of complex, highly functionalized cyclic as well as acyclic α-aryl...

Eight limonoids (1-8) including three A, B and D-seco-16-nor-type ones, 5,6-dehydrodesepoxyharperforin C2 (1), harrpernoid B (2), and its C-9S epimer, harrpernoid C (3), along with six known compounds (9-14), were isolated from fruits of Harrisonia perforata. Extensive spectroscopic analysis was used to elucidate their structures and stereochemistries. Further confirmation of structures of 1 an...

We describe several novel analogs of the seco-steroid 1,25(0H),-vitamin D,[1.25(OH),D3] and their effects on differentiation and proliferation of HL-60 human myeloid leukemic cells in vitro as well as their effects on calcium metabolism in vivo. The la-25(OH),-16ene-23yne-26,27Fo-vitamin D, is the most potent analog reported to date, having about 80-fold more activity than the reference 1,25(OH...

David W. Sukow,1 Taylor Gilfillan,1 Brenton Pope,1 Maria S. Torre,2 Athanasios Gavrielides,3 and Cristina Masoller4 1Department of Physics and Engineering, Washington and Lee University, Lexington, Virginia 24450, USA 2Instituto de Fı́sica ‘Arroyo Seco’, UNCPBA, Pinto 399 (7000) Tandil, Argentina 3Air Force Research Laboratory AFRL/EOARD, 86 Blenheim Crescent, Ruislip Middlesex HA4 7HB, United K...

6,8a-deoxy derivatives of avermectins produced by a mutant strain of Streptomyces avermitilis K20571} derived by mutation from strain K2038 producing avermectins B l a and B2a selectively2). The parent strain K2038 carries two types of mutations, C-5 0-methylation (aveD) and the selective incorporation of branched-chain fatty acid into the avermectin molecule (X). The mutant strain K2057 has an...

The data are a subsample from a data base generated for the evaluation of the Swiss active labour market policy together with Michael Gerfin. I am grateful to the Department of Economics of the Swiss Government (seco; Arbeitsmarktstatistik) for providing the data and to Michael Gerfin for his help in preparing them. The paper has been presented at the workshop Evaluation of Labour Market Polici...

A novel carbamate prodrug 2 containing a pentagastrin moiety was synthesized. 2 was designed as a detoxified analogue of the highly cytotoxic natural antibiotic duocarmycin SA (1) for the use in a targeted prodrug monotherapy of cancers expressing cholecystokinin (CCK-B)/gastrin receptors. The synthesis of prodrug 2 was performed using a palladium-catalyzed carbonylation of bromide 6, followed ...

A novel triterpenoid, holophyllane A (1), featuring a B-nor-3,4-seco-17,14-friedo-lanostane, along with its putative precursor, compound 2 were isolated from the methanol extract of the trunks of Abies holophylla. The 2D structure and relative configuration of 1 were initially determined via analysis of 1D and 2D NMR spectroscopic data and the assignment was confirmed by quantum mechanics-based...