Kojiro Wada

Sterols in Laodelphax striatellus with special reference to the intracellular yeastlike symbiotes as a sterol source

Abstract Sterols were analysed to investigate the sterol source in Laodelphax striatellus and three other rice plant-sucking homopterous insects. In L. striatellus, cholesterol, 24-methylenecholesterol and β-sitosterol were detected. The host plant (rice) contained campesterol, stigmasterol and β-sitosterol. From the honeydew excreted by L. striatellus, cholesterol, β-sitosterol and negligible amounts of campesterol were recovered. Laodelphax striatellus possesses yeastlike symbiotes which can be destroyed by high temperature. Fifth instar nymphs, which have been exposed to 35°C for 3 days in their 1 st instar, showed lower cholesterol concentration and markedly reduced amounts of 24-methylenecholesterol. From the results it is concluded that L. striatellus has two sterol sources: one from the host plant and the other from the yeastlike symbiotes which appear to provide 24-methylenecholesterol.

Structure of sporogen-ao 1, a sporogenic substance of aspergillus oryzae

Abstract A sporogenic substance, sporogen-AO 1, isolated from the culture broth of Aspergillus oryzae (NOY-2) has been shown to have the structure 1. The structure was elucidated using spectroscopic methods, especially by long range selective proton decoupling in the gated decoupled 13 C nmr spectrum and with difference nuclear Overhauser effect techniques.

Insect Feeding Inhibitors in Plants:Part III. Feeding Inhibitory Activity of Terpenoids in Plants

The insect feeding inhibitory activity of terpenoids in plants was surveyed and it was found that two sesquiterpenoids, pinguison and absinthin have the activity against Spodoptera littoralis Boisd. and the effectiveness of absinthin vary with the age or the rearing conditions of the insect.

Structure determination and absolute configuration of pisiferdiol,a new phenolic diterpenoid with a rearranged abietane skeleton from Chamaecyparis pisifera End1

Abstract Pisiferdiol 1 , isolated from C. pisifera , was shown to be a new phenolic diterpenoid with a rearranged abietane skeleton. The structure was established by several degradation reactions and from spectral evidence including LSPD experiments and NOE difference spectra. The absolute configuration was determined by employing the dibenzoate exciton chirality method on the di-p-bromobenzoate 12 .

Total synthesis of (±)-diplodialide-A

The total synthesis of a ten-membered lactone, diplodialide-A (1)[(E)-3-oxodec-4-en-9-olide], is described, involving the lactonization of the seco-acid derivative (22a) and the γ-selenenylation of the dianion of the β-keto lactone (24), followed by selenoxide elimination.

Insect Feeding Inhibitors in Plants:Part I. Isolation of Three New Sesquiterpenoids in Parabenzoin trilobum Nakai

Three new sesquiterpenoids were isolated from Parabenzoin trilobum Nakai as feeding inhibitors against a polyphagous insect, Spodoptera littoralis Boisd and an oligophagous insect, Trimeresia miranda Butler. Host selection of polyphagous insects is also discussed.

A steroid hydroxylase inhibitor, diplodialide-A, and related metabolites from Diplodia pinea

The isolation and structural elucidation of four ten-membered lactones, diplodialide-A (a steroid hydroxylase inhibitor), -B, -C, and -D are reported.

A steroid hydroxylase inhibitor, diplodialide A from Diplodia pinea

The isolation and structural elucidation of three open-chain pentaketides, diplodialide A (a steroid hydroxylase inhibitor), diplodialide B and diplodialide C are reported.

Microbiological oxidation of sterols by Coriolus hirstus

Abstract Fermentation of cholesterol with a culture of Coriolus hirstus yielded a mixture containing 7-oxo-cholesterol and hydroxylated-cholesterol derivatives. Preparation of a possible precursor of antheridiol, 7-oxofucosterol, by this fungus was also examined.

Structures of Two New Sesquiterpenes from Aspergillus oryzae

Two new sesquiterpene alcohols, 1 and 2, were isolated from a culture filtrate of Aspergillus oryzae. The structures of these compounds were deduced on the basis of their spectral evidence and synthesis of one of them.