Masateru Ono

Onionin A from Allium cepa inhibits macrophage activation.

Onionin A (1), a new, stable, sulfur-containing compound, was isolated from acetone extracts of bulbs of onion (Allium cepa), and its structure was characterized as 3,4-dimethyl-5-(1E-propenyl)-tetrahydrothiophen-2-sulfoxide-S-oxide, on the basis of the results of spectroscopic analysis. This compound showed the potential to suppress tumor-cell proliferation by inhibiting the polarization of M2 alternatively activated macrophages.

Studies on the chemical constituents of green leaves of Eucommia ulmoides Oliv.

From the green leaves of Eucommia ulmoides Oliv., 12 compounds were isolated: asperuloside, asperulosidic acid, scandoside 10-O-acetate, deacetyl asperulosidic acid, geniposidic acid, aucubin, isoquercetin, quercetin 3-O-sambubioside, rutin, astragalin, kaempherol 3-O-rutinoside and chlorogenic acid. The structures were determined on the basis of spectral data.

The Tomato Saponin, Esculeoside A

Esculeoside A (2), a spirosolane steroidal glycoside, is a major constituent isolated from Solanum lycopersicum, a commercial strain of mini tomatoes. The content variability of esculeoside A (2) was examined in mini, midi, and Momotaro tomatoes and various processed tomato products. In the green immature tomato fruit, tomatine (1) is oxidized at C-23 and C-27 to produce esculeoside A (2) in the ripe fruit. Further, esculeoside A (2) is partly converted to 3β-hydroxy-5α-pregn-16-en-20-one 3-O-β-lycotetraoside (6), a pregnane glycoside, in the overripe fruit. Esculeogenin A (3), the sapogenol of 2, is easily converted into 3β,16β-dihydroxy-5α-pregn-20-one (17). Metabolic studies showed excretion of androstane derivatives in the urine of human volunteer subjects after tomato consumption. Esculeogenin A (3) inhibited the accumulation of cholesterol esters in macrophages through its effects on acyl-CoA:cholesterol acyl transferase (ACAT). Oral administration of esculeoside A (2) to apoE-deficient mice significantly reduced serum levels of cholesterol, triglycerides, and LDL-cholesterol and ameliorated the severity of atherosclerotic lesions.

A new lignan glucoside from the stems of Callicarpa japonica Thunb. var. luxurians Rehd.

A new lignan glucoside (1) was isolated from the stems of Callicarpa japonica Thunb. var. luxurians Rehd. (Verbenaceae), along with six known lignan glucosides and three known triterpenoids. The chemical structure of 1 was characterized as (+)-lyoniresinol 3α-O-(6″-3,5-dimethoxy-4-hydroxybenzoyl)-β-d-glucopyranoside on the basis of spectroscopic data. In addition, the radical-scavenging effect of four lignans on the stable free radical 1,1-diphenyl-2-picrylhydrazyl was examined. Among the tested compounds, three compounds, including 1, showed almost the same scavenging activity as that of α-tocopherol.

A new diterpenoid and a new triterpenoid glucosyl ester from the leaves of Callicarpa japonica Thunb. var. luxurians Rehd.

A new abietane-type diterpenoid and a new oleanane-type triterpenoid glucosyl ester were isolated from the leaves of Callicarpa japonica Thunb. var. luxurians Rehd. (Verbenaceae) along with 11 known compounds, comprising seven triterpenoids, two sterols, a flavonoid, and an aliphatic glycoside. Their chemical structures were determined on the basis of spectroscopic data.

Acyclic sulfides, garlicnins L-1-L-4, E, and F, from Allium sativum.

Six novel acyclic sulfides, named garlicnins L-1-L-4 (1-4), E (5), and F (6), were isolated from the acetone extracts, with the ability to suppress M2 macrophage activation, of the bulbs of garlic (Allium sativum L.), and their chemical structures were characterized.

Content variations of the tomato saponin esculeoside A in various processed tomatoes

A tomato saponin, esculeoside A, may be metabolized into various steroidal hormones such as pregnane derivatives that are expected to exhibit various bioactivities in the body, such as anti-osteoporosis, anti-menopausal disorder and anti-tumor actions. Therefore, we attempted to examine the esculeoside A contents of fresh tomatoes, tomatoes boiled in water, tomatoes heated using a microwave oven, freeze-dried tomatoes, and commercially available processed tomato products contained in plastic bottles and cans, in order to develop a health food.

Three new aromatic glycosides from the ripe fruit of cherry tomato

Three new aromatic glycosides were isolated from the ripe fruit of cherry tomato [Lycopersicon esculentum var. cerasiforme (Dunal) Alef. (Solanaceae)] along with six known aromatic glycosides and one known steroidal alkaloid glycoside. Their chemical structures were determined on the basis of spectroscopic data as well as chemical evidence.

Characterization of a Germination-Accelerating Factor From the Silkworm (Bombyx mori Linnaeus) of Entomopathogenic Fungus Nomuraea rileyi (Farlow) Samson

The conidium of the entomopathogenic fungus, Nomuraea rileyi, has been found to germinate rapidly in the presence of a host insect-derived extract. This extract therefore appears to contain an important factor involved in host recognition by N. rileyi, although the substance (germination-accelerating factor, GAF) responsible for such unique germination behavior has yet to be identified. Our previous study was extended to the isolation of GAF from pupae of the silkworm, a host insect of N. rileyi. This present work subjects GAF to a structural analysis. The chemical structure of GAF is characterized as 2S-amino-tetradeca-4-ene-1,3R-diol (D-erythro-C14-sphingosine) based on spectroscopic data. An examination of the structure-activity relationship shows that the activity of D-erythro-C14-sphingosine was superior to that of sphingosines with shorter and longer carbon chains. It is suggested that the molecular species with a 14-carbon chain of a sphingosine is important for host recognition.

Resin glycosides from the leaves and stems of Ipomoea digitata

Alkaline hydrolysis of the ether-soluble resin glycoside (jalapin) fraction of the leaves and stems of Ipomoea digitata L. (Convolvulaceae) gave six organic acids, isobutyric, (S)-2-methylbutyric, tiglic, n-decanoic, n-dodecanoic, and cinnamic acids, and two glycosidic acids, quamoclinic acid A and operculinic acid A. Further, a new genuine resin glycoside, named digitatajalapin I, was isolated from the jalapin fraction, along with three known resin glycosides. Their structures have been determined on the basis of chemical and spectroscopic data.