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Three new glucosidic constituents (1–3) were isolated from the methanolie extract of Perilla frutescens. Two of these compounds (t and 2) were jasmonoid glucosides and were determined to be 5’-β-D-glueopyranosyloxyjasmonic acid and 3-β-D-glucopyranosyl-3-epi-2-isocucurbic acid, respectively. The other one (3) was a new glucoside of phenylvaleric acid that was elucidated to be 3-β-D-glucopyranosyloxy-5-phenylvaleric acid. Its aglycone was also found for the first time in nature.

In the course of our study on the antioxidative mechanism of (+)-catechin (1), we have examined the reaction products of 1 in the dark with radical initiator. Compound (2) was isolated as a major product by chromatographic methods and was identified as a known dehydro-dicatechin A on the basis of spectroscopic and chemical evidences. It was an oxidative dimeric flavan-3-ol, in which two units of 1 and the oxidative derivatives of 1 are linked each other. It can therefore be presumed that in the radical reaction in the dark, the A ring as well as the B ring of 1 could possess the H-atom donating ability, thus the chain radical reaction was terminated. Compound 2 was different from the reaction products under photoirradiation of 1. This is the first report on 2 derived from 1 without enzyme.

It is generally known that specimens of Carex species plants are resistant to insects and contain a variety of stilbene compounds. Some stilbene oligomers obtained from four kinds of Carex plants were analyzed by mass spectrometry. The electron impact mass spectra, secondary ionization mass spectra, and B/E linked scan spectra were measured to investigate their fragmentations.

Nisamycin, a new manumycin group antibiotic, was isolated from the culture broth of Streptomyces sp. K106. This strain was designated to genus Streptomyces by the taxonomic features. Nisamycin was purified by ethyl acetate extraction, silica gel column chromatography, preparative silica gel TLC, and Sephadex LH-20 column chromatography as a pale yellow powder. Nisamycin is active against Gram-positive bacteria and fungi, and exhibits a cytotoxic activity.

Monodemethylation of fenitrothion catalyzed by any of five purified glutathione S-transferases from rat liver predominantly produced the (S P ) -(-)-enantiomer of desmethyl fenitrothion. Mouse liver cytosolic fraction demethylated fenitrothion in the presence of glutathione to produce predominantly the (R) P -(+)-isomer. The absolute configuration of the (+)-desmethyl fenitrothion was determined as (R) P by X-ray crystallography of its brucine salt

It is known that several kinds of pyrrolidine alkaloids with a bis-amide structure are isolated from extracts from leaves and roots of Meliaceae family plants. A fragment ion m/z 85 was found in common in mass spectra of all these compounds. The structure and fragmentation mechanism of the ion were elucidated through high-resolution mass spectra and B/E as well as B2/E linked scan spectra. The fragment ion was also found useful as an index for searching compounds having similar structures.

A novel quinone antibiotic named malbranicin was isolated from the culture filtrate and mycelium of Malbranchea cinnamomea TAIM 13T54, a thermophilic fungus. The antibiotic was elucidated to be 6-(1-acetylethyl)-2-methoxy-2,5-cyclohexadiene-1,4-dione by spectral analysis. Malbranicin exhibited antimicrobial and cytotoxic activities against Gram-positive bacteria and mammalian cell lines, respectively.

A new antifungal antibiotic, S-632-C, was extracted with ethyl acetate from the culture filtrate of Streptomyces hygroscopicus S-632 and isolated through a combination of column and preparative thin-layer chromatographies on silica gel. The structure of S-632-C was determined by analysis of 1H and 13C-NMR, MS, UV and IR spectra in comparison with those of S-632-A2 (9-methylstreptimidone). The signals were assigned on the basis of 2D NMR experiments, which involved 1H-1H DQF COSY, HMQC and HMBC spectral analysis. From these results, the chemical structure of S-632-C was elucidated as 6-(3,5-dimethyl-2-oxo-4,6-octadienyl)-4-carbamoylmethyl-3,4, 5,6-tetrahydro-2- pyrone. The antibiotic exhibited exclusively weak in vitro antifungal activity against Saccharomyces spp. and similar cytotoxic activity against KB carcinoma cells, as compared with the glutarimide antibiotic S-632-A2. In addition, this antibiotic had the ability to change the morphology of ras(ts)-transformed NRK cells to that of normal cells, also a characteristic S-632-A2 and B1.

Nisamycin, a novel manumycin group antibiotic, was isolated from the culture broth of Streptomyces sp. K106. Structural elucidation of nisamycin was achieved by detailed NMR spectral analyses and comparison of the NMR data of nisamycin with those of other manumycin group antibiotics. The structure was confirmed by chromic acid oxidation. The absolute stereochemistry of nisamycin was determined to be 4R, 5S and 6R from the CD spectra of nisamycin and chromic oxidation of nisamycin. In addition, some structure activity-relationships were examined.

The cleavage reaction of cyclopropane ring is one of the useful method in organic synthesis. Especially, the sequence of cyclopropanation-homoconjugate addition is one of the accessible methods for the synthesis of natural products possessing ring- and side-chain contiguous chiral centers. This report deals with the synthetic studies of biologically active natural products possessing such chiral centers by using the opening reaction of double activated cyclopropanes.Cyclopropane derivatives have been synthesized from methyl acetoacetate by alkylation, diazo transfer followed by copper-mediated cyclopropanation. The various adducts were obtained by homoconjugate addition of nucleophiles (Gilmann reagents, Grignard reagents, cyanide anion, methanol etc.) to cyclopropanes. The opening reaction proceed with inversion of absolute configuration at the apical carbon of the cyclopropane. The adducts were converted effectively into several biologically active natural products and/or known synthetic intermediates.

(±)-1′-Epiinvictolide [(3RS,5RS,6SR,1′SR)-3,5-dimethyl-6-(1′-methylbutyl)-tetrahydro-2H-pyran-2-one] was synthesized in 11 steps from methyl 2-oxo-6-exo-methylbicyclo[3.1.0]hexane-1-carboxylate, using a cuprous iodide-mediated homoconjugate addition of Grignard reagent as the key step.

Penicillium sp. NTC-47, which had been isolated from a soil sample, produced novel dihydroquinolinones when cultured with okara (the insoluble residue of whole soybean). These metabolites, 1 and 2, were crystalline products with molecular formulas of C17H17NO5 and C17H17NO4, respectively. The structure of 1 was established to be 3-methoxy-4,5-dihydroxy-4-(4'-methoxyphenyl)-quinolinone by spectroscopic evidence and by an X-ray crystal-lographic analysis. Spectral data indicated the structure of 2 to be 5-deoxy-l. Compound 1 demonstrated toxicity against brine shrimp with an LC50 value of 20μg/ml, but 2 exhibited no activity at a dose of 100 μg/ml.

A new oleanane triterpene was isolated from okara fermented with Penicillium simplicissimum ATCC 90288. Its structure was established to be 7β, 15α, 24-trihydroxyolean-12-en-3, 11, 22-trione by spectroscopic techniques and an X-ray crystallographic analysis.

The homoconjugate addition of various organocopper reagents to doubly activated cyclopropane (1) was investigated. The otpimized yield (81 %) was obtained when using higher-order cyano cuprate in the presence of trimethylsilyl cyanide, and the reaction was applied to synthesize (±)-juvabione intermediate 9.

Three glucosides (1-3), together with known phenylpropanoids and polyacetylenes were isolated from Oenanthe javanica Blume (DC.). Glucoside 1, named oenanthoside A, is a new phenylpropanoid glucoside and was determined to be 2,3-methylenedioxy-5-allylphenyl beta-D-glucopyranoside, mainly by NMR techniques. Glucosides 2 and 3 were identified as eugenyl beta-D-glucopyranoside and pinoresinol beta-D-glucopyranoside, respectively. These were found for the first time in this plant.

Fungitoxic sesquiterpenoid chokols A, B, C, F, and K, chokolic acid B, and chokolal A were synthesized from chokol G by modifying the side chain.

The fungitoxic sesquiterpene (±)-chokolic acid A (1) was synthesized stereoselectively by starting from 2-methoxycarbonyl-(3-isopropenyl)cyclopentanone (2) in a 9% overall yield from 10 steps.

(±)-Homosarkomycin (2) and (±)-rosaprostol (3) were synthesized from (±)-methyl 2-oxo-bicyclo[3.1.0]hexane-1-carboxylate (1) by using the nucleophilic ring opening reaction on the double-activated cyclopropane ring as the key step.

The structures of the title compounds were determined by X-ray crystallographic analysis. The results lead to a revision of the previously proposed structure for photochemical cycloadduct of 9,9-ethylenedioxy-6-methoxycarbonyl-5-methyl-2-oxabicyclo[4.4.0]dec-4-en-3-one with acetylene.

To make clear which parts of the molecules contribute to the activity and how safe the oxidation products are, it is necessary to investigate the oxidation products of antioxidants from lipid peroxidation. This will also give information on the mechanism for the action of antioxidants

Etude du mecanisme d'oxydation. Isolement et identification du principal produit d'oxydation de l'epicatechine par le radical induit par le 2-methyl-propanenitrile

The reaction of bicyclo[3.1.0]hexane 1, possessing a doubly activated cyclopropane ring, with acetic acid and potassium acetate in DMSO proceeded smoothly to give the adduct 2 in good yield. A formal total synthesis of the potent anti-HIV agent (+/-)-carbovir (9) was done by converting 2 into a known precursor 8 in 8 steps via allyl alcohol 7 including the regioselective introduction of a double bond (4 to 5) and attachment of the nucleobase using the Mitsunobu reaction (7 to 8).

Monoterpene glucosides, perillosides A and C, obtained from the leaves of Perilla frutescens, were found to be inhibitors of aldose reductase (EC 1.1.1.21) which is considered to be a key enzyme in diabetic complications such as cataract. The apparent type of inhibition of rat lens aldose reductase by perillosides A and C was competitive with respect to glyceraldehyde and their K(i) values were 1.4 x 10(-4) and 2.3 x 10(-4) M, respectively. The type of inhibition by their tetraacetates was non-competitive with respect to the same substrate, although their inhibitory effects were increased by about one order of magnitude compared with those of the perilllosides and the K(i) values were 2.5 x 10(-5) and 7.1 x 10(-5) M, respectively. We also prepared related monoterpene glucosides and their tetraacetates and determined their inhibitory activities towards aldose reductase in order to elucidate the relationship between structure and inhibitory activity.

Nisamycin, a novel manumycin group antibiotic, was isolated from the culture broth of Streptomyces sp. K106. Structural elucidation of nisamycin was achieved by detailed NMR spectral analyses and comparison of the NMR data of nisamycin with those of other manumycin group antibiotics. The structure was confirmed by chromic acid oxidation. The absolute stereochemistry of nisamycin was determined to be 4R, 5S and 6R from the CD spectra of nisamycin and chromic oxidation of nisamycin. In addition, some structure activity-relationships were examined.

Alisamycin is a new manumycin group antibiotic. Manumycin group antibiotics have three asymmetric carbons at C4, C5, and C6 in their structures. The absolute structure of alisamycin was determined by the exciton chirality method and CD spectrum of the oxidative product of alisamycin. Configurations of C4, C5, and C6 were assigned to be 4R, 5S, and 6R.

(1992). Simple Synthesis of (±)-Chokol G. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 2, pp. 351-352.

A novel quasi-dimeric oxidation product of (+)-catechin, formed during the radical-scavenging reaction that prevents lipid peroxidation, was isolated by chromatography, and its structure was elucidated by infrared, ultraviolet and1H and13C nuclear magnetic resonance spectra and mass spectrometry. It was 5′-[3-[3,4-(3′,5′-dihydroxy) benzo-8-oxo-2,7-dioxabicyclo [4.4.0] deca-3,9-dien-10-yl]acryloyl]-(+)-catechin. It is an unusual type of dimer of flavan-3-ol derivatives, which is different from the naturally formed dimer, procyanidin.

(1991). Ankalactone, a New α,β-Unsaturated γ-Lactone from Monascus anka. Agricultural and Biological Chemistry: Vol. 55, No. 3, pp. 899-900.

Three isomers of 2H,8H-benzo[1,2-b: 3,4-b′]dipyran and 2H,8H-benzo[1,2-b: 5,4-b′]dipyran, were synthesized by dehydrogenation of the dihydrobenzodipyran derivatives using DDQ or NBS and by dehydration of the secondary alcohol prepared by reduction of 4-phenylcoumarin derivatives bearing dihydropyranone ring with sodium borohydride.

The condensation of 6', 7-bis(benzoyloxy)-2', 4'-dimethoxyisolfavone (18) with 2-methyl-3-buten-2-ol, followed by hydrolysis of the resultant 6', 7-bis(benzoyloxy)-2', 4'-dimethoxy-3'-(3-methyl-2-butenyl)isoflavone (19) gave 6', 7-dihydroxy-2', 4'-dimethoxy-3'-(3-methyl-2-butenyl)-isoflavone (licoricone) (1). Its isomer, 6', 7-dihydroxy-2', 4'-dimethoxy-5'-(3-methyl-2-butenyl)-isoflavone (2), was also synthesized from 7-benzoyloxy-6'-hydroxy- or 6', 7-bis(benzoyloxy)-2', 4'-dimethoxy-5'-(3-methyl-2-butenyl)isoflavone (11 or 20).

(±)-Vitrenal (1), a sesquiterpene aldehyde with a novel vitrane skeleton, was synthesized from a monoterpene piperitenone (2) by 12-step reactions in ca. 7% overall yield. 2-Formyl-isocarane, derived from 2 via (±)-isocaran-2-one was allylated stereospecifically and, after protection of the formyl group, the allyl chain was modified to a 4-methoxy-3-butenyl group. Acid treatment of the masked dialdehydic intermediate yielded 1 by concomitant deprotection and aldol condensation.

2′,4′,5,7-Tetrahydroxyisoflavone was partially benzoylated with benzoyl chloride to give 7-benzoyloxy-2′, 4′,5-trihydroxyisoflavone. The condensation of the 7-(benzoyloxy)isoflavone with 2-methyl-3-buten-2-ol, followed by the hydrolysis of the resultant 3′-(3-methyl-2-butenyl)isoflavone gave licoisoflavone A. Its 5′-(3-methyl-2-butenyl) isomer was also synthesized from 5-benzoyloxy-2′,4′,7-trihydroxyisoflavone in a similar manner.

Ion kinetic energy spectroscopy(IKES)provides new and useful information on the structure of ions formed by mass spectrometer. This method was applied to the distinc tion of isomeric monoterpene pairs whose mass spectra are nearly identical. It is shown that the IKE spectra can be used for such isomers, which was exemplified by the case of borneol and iso-borneol.

A series of the enantiomeric sesquiterpenoids corresponding to the antipodos of those obtained from higher plants were isolated from the liverwort Riccardia jackii. This result is an additional example suggesting the special position taxonoinical of the liverworts in plant kingdom

The mass spectra of fifteen diterpenoids belonging to the new carbon skeletons of verrucosane, neoverrucosane and homoverrucosane are examined. From their spectra the relationship between fragmentation patterns and substituted modes of these diterpenoids is discussed.

Ammonia and isobutane chemical ionization mass spectra of the intact flavone glycosides are described. The protonated molecular ion(MH+) are peaks very weak and glycosidic bond cleavage is observed as the major fragmentation pathway. Consequently, the mass spectra exihibit the protonated aglycone ions as the base peak and the various sugar-derived ions.

Mass spectra of three naturally occurrig ent-15-ketokauranoids, (I), (III)and(IV), and their derivatives, (II)and(V), were measured and their characteristic fragmentations were discussed.

The structures and absolute configurations of the two sesquiterpene aldehydes, (–)-isobicyclogermacrenal (1) and (–)-lepidozenal (2), which were isolated from the liverwort Lepidozia vitrea, have been determined on the basis of chemical and spectroscopic evidence to be (6R,7S)-6,11-cyclogermacra-1(10)-E,4E-dien-14-al and (6R,7S)-lepidoza-1 (10)E,4E-dien-14-al, consisting of the cis- and trans-10,3-bicyclic ring systems. The structure of the former (1) has been confirmed by a single-crystal X-ray analysis of its hydroxy derivative (7). The molecular conformations, biogenetical features, and biological activity are also described.

The structure of a new antitumor antibiotic, myrocin C, from a strain of Myrothecium verrucaria was characterized as a pentacyclic pimarane diterpene composed of a gamma-lactol group and a unique cyclopropane ring on the basis of its physico-chemical properties and spectroscopic data as well as a single-crystal X-ray diffraction analysis of its monoacetyl derivative.

5,6-Dihydroxy-3,4′,8-trimethoxyflavone, which was the proposed structure of the pigment occuring in Conyza stricta, was synthesized from 2,3,5,6-tetramethoxyacetophenone in six steps. The natural pigment was identical not with the synthesized flavone, but with 5,7-dihydroxy-3,4′,8-trimethoxyflavone, an isomer of the former.