Shinsaku Natori

Carcinogenicity examination of quercetin and rutin in ACI rats

Carcinogenicity of quercetin and rutin were examined in inbred ACI strain rats. Rats were given a diet containing 1% or 5% quercetin or 5% rutin for 540 days, or 10% quercetin and 10% rutin for 850 days. Rats in control groups were fed a normal basal diet. Most tumors found in experimental groups were also found in the corresponding control groups. Furthermore, there was no significant difference between the incidence of tumors in the experimental or control groups (P greater than 0.05). Thus, quercetin and rutin tested were not shown to be carcinogenic to ACI rats.

Mutagenicity of anthraquinones in the Salmonella preincubation test

The mutagenicities of 15 naturally occurring anthraquinones were examined in Salmonella typhimurium strains TA98, TA100 and TA2637 by the preincubation method. 7 of the 15 compounds tested, i.e., chrysazin, emodin, islandicin, alizarin, chrysophanol, 2-hydroxyanthraquinone and emodic acid, were strong mutagens in strain TA2637 with metabolic activation. All of these compounds contain 1-3 hydroxyl groups, and some also have methyl groups. Cynodontin, an anthraquinone with 4 hydroxyl groups and 1 methyl group, was only slightly mutagenic in strain TA2637. 2-Hydroxyanthraquinone, alizarin, emodin, islandicin and chrysazin were also mutagenic in strain TA100 with S9 mix. All the bisanthraquinones tested, i.e., skyrin, (+)rugulosin, (-)luteoskyrin, (-)rubroskyrin and sennoside A, were non-mutagenic in this test system with or without metabolic activation. Unsubstituted anthraquinone and anthrone were also non-mutagenic. These results show that hydroxyl substituents are necessary for the mutagenicity of anthraquinones, the optimal substitutions being 1-3 hydroxyl groups per molecule. The 4th hydroxyl group, in the compound cynodontin reduces the mutagenicity considerably.

The structures of arundoin, cylindrin and fernenol : Triterpenoids of fernane and arborane groups of imperata cylindrica var. koenigii☆

Abstract Five triterpenoids, arundoin (Ia), cylindrin (IIa), fernenol (Ib), isoarborinol (IIb) and simiarenol (IVa), have been isolated and the structures of Ia, IIa and Ib determined. The biogenetical relationship of these compounds, based on the established structures is discussed.

3β-p-Hydroxybenzoyldehydrotumulosic acid from Poria cocos, and its anti-inflammatory effect

The structure of a new triterpene derivative isolated from Poria cocos was determined to be 3β-p-hydroxybenzoyldehydrotumulosic acid by spectral and chemical methods. 3β-p-hydroxybenzoyldehydrotumulosic acid showed marked inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)- and arachidonic acid (AA)-induced ear inflammation in mice. The 50% inhibitory doses of 3β-p-hydroxybenzoyldehydrotumulosic acid were 0.27 and 1.25 mg per ear on TPA- and AA-induced inflammation, respectively.

Mutagenicity of natural naphthoquinones and benzoquinones in the Salmonella/microsome test

The mutagenicities of naturally occurring naphthoquinones and benzoquinones were tested by the pre-incubation method with Salmonella typhimurium strains TA98, TA100 and TA2637, which all contain plasmid pKM101. 6 of the 16 naphthoquinones tested, i.e., plumbagin, naphthazarin, 2-hydroxy-naphthoquinone, vitamin K3 (menadione), juglone and 7-methyljuglone, were mutagenic to strain TA2637 with metabolic activation. Except for juglone and 7-methyl-juglone, these compounds also had slight mutagenic effects on strain TA98 with S9 mix. All the mutagenic naphthoquinones contain one or two hydroxyl and/or methyl substituents. The naphthoquinone mompain, which has four hydroxyl groups, was not mutagenic. Unsubstituted beta-naphthoquinone, naphthoquinones with a prenyl side chain and all bi-naphthoquinone derivatives tested were non-mutagenic. None of the 13 benzoquinones examined was mutagenic to any of the strains used with or without metabolic activation. These results show that natural naphthoquinones are mutagenic when they have only one or two hydroxyl and/or methyl substituents.

Six new 10-pheynl-[11]cytochalasans, cytochalasins N - S from phomopsis SP.

Abstract From Phomopsis sp. (68-GO-164) six new cytochalasans named cytochalasins N, O, P, Q, R and S were isolated, together with the four known compounds, epoxycytochalasins H and J and cytochalasins H and J. The structures ( 5 – 10 ) of the new compounds as 10-phenyl-[11]cytochalasans were determined from spectral data, especially 1 H and 13 C NMR, and by chemical correlation with known compounds. Cytochalasins P, Q, R and S ( 7 – 10 ) have novel diol-type structures in the cyclohexane part of the molecules.

Distribution of tetracyclic triterpenoids of lanostane group and sterols in the higher fungi especially of the polyporaceae and related families

Abstract The fruit bodies of 97 species of wood-rotting fungi, mainly of Polyporaceae and related families, were examined for the distribution of triterpenes and sterols. Triterpene acids of lanostane group were detected exclusively from the fungi causing brown-rot of woods, while sterols were found to occur commonly in both brown-rot and white-rot fungi. The most abundant sterol was found to be ergosta-7,22-dien-3β-ol. The presence and absence of the triterpene acids is discussed from the point of view of fungal phylogeny.

The sesquiterpenoid carcinogen of bracken fern, and some analogues, from the pteridaceae

Abstract Ptaquiloside, the sesquiterpenoid carcinogen of Pteridium aquilinum, was isolated from Pteris cretica and Histiopteris incisa. Three new sesquiterpene glycosides of the illudane type, analogues of ptaquiloside, were isolated from Hypolepis punctata and Dennstaedtia hirsta. They are named hypolosides A, B and C, and characterized as compounds related to pterosin Z.

Cytotoxicity of new cytochalasans fromChaetomium globosum

Nachweis, dass CHCl3-Rohextrakte aus Myzelien und Filtraten der Zuchtmedien vonChaetomium globosum Kunze ex Fries einen akuten toxischen Effect auf HeLa-Zellen in vitro, sowie auf Mäuse zeigten. Chaetoglobosine die aus Mycelium-Rohextrakt isoliert wurden und chemisch zu den Cytochalasanen gehören, induzierten in HeLa-Zellen eine Polynukleierung und multipolare Kernverteilung. Auch beim Chaetogobosin wird eine Mikrofilament-Schädigung angenommen.

Mutagenicity of isoquinoline alkaloids, especially of the aporphine type

The mutagenicity of 44 isoquinoline alkaloids was tested in Salmonella typhimurium TA100 and TA98 in the presence or absence of S9 mix. The alkaloids tested included compounds from the isoquinoline, benzylisoquinoline, bisbenzylisoquinoline, monoterpene isoquinoline, berberine, morphinane, hasubanan, benzo[c]phenanthridine and aporphine groups. Among the alkaloids tested, liriodenine was the most potent mutagen for TA100 and roemerine was the most potent for TA98. A clear structure-mutagenicity relationship was observed in a series of aporphine alkaloids (aporphine, dehydroaporphine, 7-oxoaporphine and 4,5-dioxoaporphine), and 10,11-non-substituted aporphines were suggested to exert their mutagenicity through metabolic activation of the 10,11 positions, possibly as the 10,11-epoxides.