Tsunematsu Takemoto

The moulting hormone activity of ecdysterone and inokosterone isolated from Achyranthis Radix

Abstract The moulting hormone activity of ecdysterone (iso-inokosterone) and inokosterone isolated from Achyranthis Radix has been examined using the housefly, Musca domestica , and the silkworm, Bombyx mori . These chemicals showed a high activity as the hormone, although pupal-adult mixtures were induced indirectly by injecting large doses.

Structure-activity relationship of ericaceous. Toxins on acute toxicity in mice

Abstract The acute toxicity of 36 samples of ericaceous toxins and their congeners has been determined using mice. Those whose LD50 values are low (

Detoxication mechanism of Bombyx mori against exogenous phytoecdysone ecdysterone

Abstract The absorption, distribution, catabolism, and excretion of ecdysterone in silkworm ( Bombyx mori ) larvae have been examined using 3 H-ecdysterone in order to obtain information about the defensive mechanism of insects against exogenous phytoecdysones. Thus, it has been found by means of scintillation counting and whole-body autoradiography that the absorption of the ingested ecdysterone into the body tissues is slow and limited and its excretion into the digestive tract is rapid and easy, this behaviour being fundamentally different from that of the ingested β-sitosterol, the essential nutrient, which is quite rapidly absorbed into the body tissues and excreted into the digestive tract very slowly. The absorbed acdysterone is rapidly catabolized into compounds A and B which have probably little or no moulting hormone activity as judged from the fact that the administered ecdysterone is rapidly inactivated. The combined mechanism is considered to play an important role in the defence of the insect against ingested phytoecdysones. The catabolic activity on ecdysterone of the silkworm has been found to change with the different growth period which is corresponding to the variation of the content of the endogenous ecdysones, suggesting that the hormone content in the insect is regulated by the rise and fall of the catabolic activity.

Structure and absolute configuration of α-rotunol and β-rotunol, sesquiterpenoids of Cyperus rotundus☆

Abstract Two novel sesquiterpenic keto-alcohols, α-rotunol and β-rotunol, have been isolated from nutgrass, Cyperus rotundus ;Cyperaceae). The stereostructure II of β-rotunol is based on spectral properties and by transformation to the dienone (V) which has also been derived from hinesol (VI). α-Rotunol has been given the stereostructure I based on its physico-chemical properties.

Sengosterone, an insect metamorphosing substance from Cyathula capitata: Structure

Abstract A novel C29 insect-metamorphosing substance, cyasterone, has been isolated from Cyathula capitata (Amaranthaceae). Chemical and physico-chemical studies of cyasterone and its derivatives (II–V), and in particular its transformation into 14α-hydroxy-2,3-seco-5β-pregn-7-ene-6,20-dione-2,3-dial (VI) and 2,4-dimethyl-3-(2-oxoethyl)-4-butanolide (VII) have established the structure of cyasterone as shown in formula I.

Inokosterone, an insect metamorphosing substance from Achyranthes fauriei : Absolute configuration and synthesis☆

Abstract Inokosterone, a phytoecdysone isolated from Achyranthes fauriei (Amaranthaceae), has been partially acetylated to give the 2,26-diacetate (4) which has been converted into methyl 5 - acetoxy - 4 - methylpentanoate (7), showing no apparent [α]D, and 2β - acetoxy - 3β,14α - dihydroxy - 5β - pregn - 7 - ene - 6,20 - dione (8). Chemical and physiochemical studies have shown the configurations at C-20 and C-22 to be R. Inokosterone has thus been concluded to be a mixture of C-25 epimers of (20R,22R) - 2β,3β,14α,20,22,26 - hexahydroxy - 5β - cholest - 7 - en - 6 - one (1). After the synthesis of the model compound, a C-25 epimeric mixture of (20R,22R) - 3β,20,22,26 - tetrahydroxy - 5α - cholestane (23), inokosterone has been synthesized via (20R) - 2β,3β,14α,20 - tetrahydroxy - 20 - formyl - 5β - pregn - 7 - en - 6 - one (25) by Grignard reaction with 4 - (tetrahydrofuran - 2 - yloxy) - 3 - methylbutynylmagnesium bromide (15) followed by hydrogenation and hydrolysis. The use of an NMR shift reagent with the inokosterone acetates (9, 29) and the optical activity measurement of α - methylglutaric acid (3) derived from inokosterone have established that inokosterone is a 1:2 mixture of the C-25 R and S epimers.

Picrasins, simaroubolides of Japanese quassia tree Picrasma quassioides☆

Abstract From the Japanese quassia tree, Picrasma quassioides (Simaroubaceae), new bitter principles (simaroubolides), picrasin A, B, C, D, E, F and G have been isolated whose stereostructures have been elucidated on the basis of chemical and physical evidence. The relative bitterness of the picrasins and the related simaroubolides has been measured.

Effects of glutamic acid analogues on identifiable giant neurones, sensitive to β‐hydroxy‐L‐glutamic acid, of an African giant snail (Achatina fulica Férussac)

1 The effects of the seven glutamic acid analogues, α‐kainic acid, α‐allo‐kainic acid, domoic acid, erythro‐L‐tricholomic acid, DL‐ibotenic acid, L‐quisqualic acid and allo‐γ‐hydroxy‐L‐glutamic acid were examined on six identifiable giant neurones of an African giant snail (Achatina fulica Férussac). 2 The neurones studied were: PON (periodically oscillating neurone), d‐RPLN (dorsal‐right parietal large neurone), VIN (visceral intermittently firing neurone), RAPN (right anterior pallial neurone), FAN (frequently autoactive neurone) and v‐RCDN (ventral‐right cerebral distinct neurone). Of these, d‐RPLN and RAPN were excited by the two isomers (erythro‐ and threo‐) of β‐hydroxy‐L‐glutamic acid (L‐BHGA), whereas PON, VIN, FAN and v‐RCDN were inhibited. L‐Glutamic acid (L‐Glu) had virtually no effect on these neurones. 3 α‐Kainic acid and domoic acid showed marked excitatory effects, similar to those of L‐BHGA, on d‐RPLN and RAPN. Their effective potency quotients (EPQs), relative to the more effective isomer of L‐BHGA were: 0.3 for both substances on d‐RPLN, and 1 for α‐kainic acid and 3‐1 for domoic acid on RAPN. α‐Kainic acid also had excitatory effects on FAN and v‐RCDN (EPQ for both: 0.3), which were inhibited by L‐BHGA but excited by γ‐aminobutyric acid (GABA). 4 Erythro‐L‐tricholomic acid showed marked effects, similar to those of L‐BHGA, on VIN (EPQ: 0.3) and RAPN (EPQ: 3‐1), but produced weaker effects on PON and d‐RPLN (EPQ: 0.1). 5 DL‐Ibotenic acid produced marked effects, similar to those of L‐BHGA, on PON, VIN (EPQ for both: 1) and RAPN (EPQ: 1‐0.3), but had weak effects on d‐RPLN (EPQ: <0.1) and FAN (EPQ: 0.1). It had excitatory effects on v‐RCDN (EPQ: 0.1). This neurone was inhibited by L‐BHGA but excited by GABA. 6 L‐Quisqualic acid showed the same effects as L‐BHGA on all of the neurones examined (EPQ range 30–0.1). It was the most potent of the compounds tested on RAPN (EPQ: 30‐10), FAN (EPQ:30) and v‐RCDN (EPQ:3). 7 α‐Allo‐kainic acid and allo‐γ‐hydroxy‐L‐glutamic acid had no obvious effect on any of the neurones examined. 8 As described above, the responses of the neurones examined to these substances varied widely. However, L‐quisqualic acid generally had effects on the neurones similar to those of L‐BHGA; the L‐BHGA‐excited neurones were also excited by α‐kainic acid and domoic acid.

Rearrangement of 4,5-epoxy-eudesmanes with boron trifluoride

Abstract Three epoxides (IX, XIX and XX) prepared from the eudesm-4-enes (VIII and XVIII) on treatment with BF 3 -etherate have been found to undergo skeletal rearrangement resulting in the formation of a number of ketones; i.e. 5- epi faurinan-4-one (X), 1( R )-isopropyl-3-(1′-methyl-5-oxohexylidene)cyclopentane (XI) and 1( S ),7( S )-dimethyl-4( R )-isopropyl-bicyclo[5.3.0]decan-6-one (XII) from 4α,5α-epoxy-10- epi eudesmane (IX), 1( R ),7( S )-dimethyl-4( R )-isopropyl-bicyclo[5.3.0]decan-6-one (XXI) from 4α,5α-epoxy-eudesmane (XIX), and the unsaturated methyl ketone (XI) from 4β,5β-epoxy-eudesmane (XX).

Poststerone, a metabolite of insect metamorphosing substances from Cyathula capitata

Abstract A C 21 steroid, poststerone, has been first isolated from Cyathula capitata (Amaranthaceae), and identified as 2β,3β,14α-trihydroxy-5β-pregn-7-ene-6,20-dione (I).