Matsumi Doe

Khayanolides, rearranged phragmalin limonoid antifeedants from Khaya senegalensis

Abstract Three new rearranged phragmalin-type limonoids, named khayanolides A, B and C, were isolated as insect antifeedant together with four known rings B,D-seco compounds, seneganolide, methyl angolensate and its 6-hydroxy and 6-acetoxy derivatives from the ether extract of the stem bark of Khaya senegalensis. The structure of new compounds was elucidated by spectroscopic means and the absolute structure of khayanolide A was established by X-ray analysis and CD study. The antifeedant activity of the isolated compounds was also reported.

Unprecedented sugar-dependent in vivo antitumor activity of carbohydrate-pendant cis-diamminedichloroplatinum(II) complexes.

Eight carbohydrate-pendant platinum(II) complexes have been synthesized from carbohydrate-diamine conjugates. D-Glucose, D-mannose, D-galactose, D-xylose, and L-glucose are attached to the dichloroplatinum(II) moiety by 1,3- or 1,2-diaminopropane chelates through with an O-glycoside bond. All the carbohydrate moieties reduced the toxicity inherent with platinum(II) complexes.

A Novel Sphingoglycolipid Containing Galacturonic Acid and 2-Hydroxy Fatty Acid in Cellular Lipids of Sphingomonas yanoikuyae

A novel sphingoglycolipid was isolated from Sphingomonas yanoikuyae, and its structure was identified as a galacturonosyl-beta (1-->1)-ceramide. This was a characteristic sphingoglycolipid present in S. yanoikuyae and certain other species of Sphingomonas, such as Sphingomonas mali, Sphingomonas terrae, and Sphingomonas macrogoltabidus, but not in the type species of Sphingomonas, Sphingomonas paucimobilis.

Three novel bis(indole) alkaloids from a stony coral, Tubastraea sp.

Three novel bis(indole) alkaloids with an unprecedented skeleton have been isolated from a stony coral, Tubastraea sp. These indoles could biogenetically be derived from two molecules of aplysinopsin via a Diels–Alder reaction.

Limonoids from the stem bark of Cedrela odorata

Four nomilin/obacunol derivatives and a swietenolide derivative, together with seven known limonoids, were isolated from stem bark of Cedrela odorata and their structures established by spectroscopic methods. Antifeedant activity of the isolated compounds was also tested.

Khayanolides A and B, new rearranged phragmalin limonoid antifeedants from Khaya senegalensis

Abstract Khayanolides A and B, two new rearranged phragmalin limonoids, were isolated as insect antifeedants together with two known rings B,D-seco compounds, methyl angolensate and its 6-hydroxy derivative from the ether extract of the stem bark of Khaya senegalensis. The structure of the new compounds was elucidated by spectroscopic means and the absolute structure of khayanolide A was established by X-ray analysis and CD study. The antifeedant activity is also reported.

Aplysinopsin dimers from a stony coral: Tubastraea aurea

- Five novel bis(indole) alkaloids, which were composed of two molecules of aplysinopsin have been isolated from a stony coral, Tubastraea aurea. Their structures were elucidated on the basis of spectroscopic methods.

Diterpenoids from Euphorbia paralias

Two segatane diterpenoids containing a bicyclic [4,3,1] ring system were isolated, together with 11 known diterpenoids, four segetanes, five jatrophanes and two paralianes, from the aerial parts of Euphorbia paralias. The structures of the new compounds were established by spectroscopic means, including by 2D NMR and CD spectroscopic analyses. The antifeedant and antiviral activities of the isolated compounds are also described.

Cytotoxic Isomalabaricane Derivatives and a Monocyclic Triterpene Glycoside from the Sponge Rhabdastrella globostellata

Seven new isomalabaricane derivatives, rhabdastins A-G (1-7), and a new monocyclic triterpene glycoside, rhabdastoside A (8), have been isolated from the methanol extract of the sponge Rhabdastrella globostellata, collected at Amami-oshima, Japan. Three of them were isolated as their corresponding methyl esters, rhabdastins A-D (1-3). Their structures were determined on the basis of spectroscopic and X-ray diffraction analyses. The isolated compounds were evaluated for their cytotoxicity against the proliferation of promyelocytic leukemia HL-60 cells. Compounds 4, 5, 7, and 11, possessing a cyclopentane side chain, exhibited weak activity, with IC(50) values of 21, 29, 44, and 11 μM, respectively, while compounds 1, 2, and 3, with a 2-substituted-propanoate side chain, were inactive at 100 μM. In addition, the mechanism of cytotoxicity of compounds 4 and 5 was investigated.

Cytotoxic Biscembranes from the Soft Coral Sarcophyton glaucum

Seven new tetracyclic biscembranes (1-7) have been isolated from the soft coral Sarcophyton glaucum. Four (1-4) may be formed biogenetically by a Diels-Alder reaction of Delta(4(5)) and Delta(8(9)) geometrical isomers of methyl sarcoate and Delta(21(34), 35(36)) dienes, including two with a tetrahydrofuran ring between C-27 and C-30 (3, 4), and three biscembranes (5-7) are probably derived from methyl sarcoate isomers with Delta(1(14), 4(5), 8(9)) and a cembrane diene. Their structures were established on the basis of spectroscopic methods. Six of them (1-5, 7) exhibited weak cytotoxic activity against proliferation of human promyelocytic leukemia cells (HL-60).