Itsuo Nishioka's research while affiliated with University of North Carolina at Chapel Hill and other places
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Publications (319)
A new ellagitannin, jolkinin (2), was isolated from the fresh whole plant of Euphorbia jolkinii, and its structure, including absolute configuration, was determined on the basis of spectroscopic and chemical evidence. A highly oxygenated acyl group with unique hexacyclic structure is attached to the 2,4-positions of 1-O-galloyl-3,6-(R)-hexahydroxyd...
Nine tannins, including gallo- and ellagitannins, were evaluated as potential inhibitors of HIV replication. 1,3,4-Tri-O-galloylquinic acid [1], 3,5-di-O-galloyl-shikimic acid [2], 3,4,5-tri-O-galloylshikimic acid [3], punicalin [6], and punicalagin [7] inhibited HIV replication in infected H9 lymphocytes with little cytotoxicity. Two compounds, pu...
A chemical examination of Turkish galls (Quercus lustitanica) has led to the isolation of four C-glycosidic hydrolyzable tannins, among which three were found to be identical with the known compounds pterocarinin A [1], castalagin [2], and castavaloninic acid [4]. The structure of the new tannin, isocastavaloninic acid [5], was established on the b...
Forty-three polyphenols from tea leaves were evaluated for their anti-oxidative effect against lipid peroxidation by the ferric thiocyanate method in vitro. Among these, 1,4,6-tri-O-galloyl-beta-D-glucose (hydrolyzable tannin) showed the highest anti-oxidative activity against lipid peroxidation, even stronger than that of 3-tert.-butyl-4-hydroxyan...
The structure of cercidinin A, an ellagitannin isolated from the bark of Cercidiphyllum japonicum, was revised to 1,2,6-tri-O-galloyl-3,4-(R)-hexahydroxydiphenoyl-beta-D-glucose by two-dimensional NMR spectral analysis. Cercidinin A represents the first ellagitannin possessing a hexahydroxydiphenoyl group at the 3,4-positions of a modified 4C1-gluc...
Fifty-one tannins and forty-one flavonoids isolated from Oriental medicinal herbs were evaluated for their antioxidant ability with a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-generating system. The results showed that tannins and certain flavonoids are potential free-radical scavengers, and that their activity against the DPPH radical is closel...
Paraquat is a bipyridyl herbicide which is hardly absorbed into the body by inhalation, but causes serious injuries when ingested; death usually results within 2 days after a dose of 50 mg/kg. The cytotoxic action of paraquat is said to be mediated by the production of paraquat radicals through reduction of paraquat in cells and the subsequent indu...
A study was conducted to clarify whether magnesium lithospermate B ameliorates cisplatin-induced renal injury in terms of lactate dehydrogenase and malondialdehyde leakage from LLC-PK1 cells in culture. Magnesium lithospermate B was shown to suppress the cytotoxicity of cisplatin, the suppressive effect increasing with the dose of magnesium lithosp...
Subtotally nephrectomized rats were found to have decreased activities of superoxide dismutase (SOD) and catalase, and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that the amount of hydroxyl radical in the residual kidney tissue was greater than that in normal rat kidney. This indicated both direct and indirect involvement of...
Two new ellagitannins, named syzyginins A and B, were isolated from the leaves of clove (Syzygium aromaticum.). Syzyginin A was characterized as 1,2,3-tri-O-galloyl-4,6-(S)-tergalloyl-beta-D-glucopyranose. Syzyginin B was a novel hydrolysable tannin possessing a new aromatic acyl group, syzygyl, which has a dibenzo-1,4-dioxin structure probably der...
Thirty-eight tea polyphenols were evaluated for their inhibitory effect against HIV replication in H9 lymphocyte cells. 8-C-Ascorbyl (−)-epigallocatechin (13) and theasinensin-D (32) demonstrated relatively potent anti-HIV activity with EC50 values of 4 and 8 μg/mL and therapeutic indexes of 9.5 and 5, respectively.
The levels of urea nitrogen, creatinine, methylguanidine and guanidinosuccinic acid, which accumulate in blood in parallel with the progress of renal failure after adenine administration, were decreased significantly in rats given Galla Rhois, Moutan Cortex or Paeoniae Radix extract. Administration of Galla Rhois extract was found to be more effect...
The levels of urea nitrogen, creatinine, methylguanidine and guanidinosuccinic acid, which accumulate in the blood in parallel with the progress of renal failure after adenine administration, were decreased markedly and significantly in rats given Ephedrae Herba extract. Administration of the fraction III of Ephedrae Herba extract was found to be m...
Magnesium lithospermate B, a compound newly isolated from Dan Shen, was given orally to rats for 70 days after excision of five-sixths of their kidney volume. As a result, mesangial proliferation, tubulo-interstitial lesions and glomerular sclerotic lesions, which were conspicuous in rats that were not given magnesium lithospermate B after nephrect...
Previously we have isolated the quaternary base alkaloids, magnoflorine and phellodendrine, from Phellodendri Cortex (cortex of Phellodendron amurense Rupr., Rutaceae) as the biologically active principles to suppress local graft-versus-host (GvH) reactions in mice. In this paper, we focus on phellodendrine. Phellodendrine suppressed local semisyng...
Nine crude drugs containing tannins were selected in order to examine their actions on rats with renal failure. The levels of urea nitrogen, creatinine (Cr), methylguanidine (MG) and guanidinosuccinic acid (GSA) were decreased markedly and significantly in rats given Ephedrae Herba. Chebulae Fructus and Geranii Herba produced the same effect on ura...
A new dimeric ellagitannin, bischofianin, was isolated from the leaves of Bischofia javanica, together with five known tannins. The structure was elucidated on the basis of spectroscopic and chemical evidence.
We previously reported that Wen-Qing-Yin (Unsei-in), a traditional Chinese blended medicine, inhibited the induction phase of various kinds of delayed type hypersensitivity (DTH) and local graft-versus-host (GvH) reactions, but did not affect humoral immune responses or the effector phase of DTH in experimental animals. In another report, we demons...
The antihypertensive effect of magnesium lithospermate B isolated from Salviae Miltiorrhizae Radix was evaluated using spontaneously hypertensive rats (SHR). Oral administration of magnesium lithospermate B lowered the systolic, mean and diastolic blood pressures in SHR, in comparison with the progressive hypertensive observed in untreated control...
We have screened several chinese medicinal herbs for the presence of antifibrotic agents. An aqueous extract of Salviae miltorrhizae Radix was found to inhibit collagen secretion by human skin fibroblasts without affecting DNA or noncollagen protein synthesis. We have subsequently purified the material exhibiting the inhibitory activity and identif...
Callus was induced from the fruit galls of Actinidia polygama and the regenerated plants from the callus tissue were cultured. The formation of triterpenoids in the callus was confirmed. Eight triterpenoids containing two new ones were isolated from the callus. The triterpenoid composition found in the callus tissue was compared with those in the r...
Chemical examination of the leaves of Rubus lambertianus Seringe (Rosaceae) has led to the isolation of four new ellagitannins, which were characterized on the basis of chemical and spectroscopic evidence to be dimers [lambertianins A (6) and B (7)], a trimer [lambertianin C (8)] and a tetramer [lambertianin D (10)], all having sanguisorbic acid es...
We examined the effects of purified tannins and related compounds (33 species) on NADH-ubiquinone-1 oxidoreductase activity in four kinds of organism (Paracoccus denitrificans, Bacillus subtilis, Photobacterium phosphoreum, and Thermus thermophilus HB-8) and rat liver mitochondria. In addition to pentagalloylglucose, which was reported as a potent...
A study was conducted to investigate the effects of magnesium lithospermate B on the uraemic symptoms and development of hypertension in rats with adenine-induced renal failure. Chronic administration of 10 mg/kg body weight/day magnesium lithospermate B significantly reduced serum urea nitrogen, creatinine, methylguanidine, guanidinosuccinic acid...
Fifty-two out of 60 tannins, including gallo-, ellagi-, condensed, and complex tannins, are inhibitors of human DNA topoisomerase II in vitro. Thirty-six compounds that completely inhibited enzyme activity at a concentration of 500 nM or less, as assessed by ATP-dependent unknotting of P4 phage DNA, were at least 100-fold more potent than the clini...
A study was conducted to examine the effect of magnesium lithospermate B on both the urinary and renal total and active kallikrein and prokallikrein in rats with adenine-induced renal failure. In rats given magnesium lithospermate B at a dose of 10 mg/kg body weight/day for 12 days, significant increases of urinary total and active kallikrein were...
Two Dan Shen preparations commercially available in China were given intraperitoneally to rats with renal failure in order to investigate their effects on blood and urine components. In rats given an injection of compound Dan Shen composed of Dan Shen and Jiang Xiang, effects similar to those found after administration of magnesium lithospermate B...
From the dried leaves of Syzygium aromaticum MERR. et PERRY (Myrtaceae), eleven new compounds, i.e., eugenol 4-O-β-D-(6'-O-galloyl)glucopyranoside (17), 2-methyl-5,7-dihydroxychromone 8-C-β-D-glucopyranoside (18) and its 6'-O-gallate (19), 2,4,6-trihydroxyacetophenone 3-C-β-D-glucopyranoside (20) and its 2'-O- (21), 6'-O- (22), 2',3'-di-O- (23), 2'...
The homogeneity of a population of clonally propagated Aconitum carmichaelii Debx. was confirmed by quantitative analysis of aconitine-type alkaloids by HPLC. Quantitative fluctuation of aconitine-type alkaloids occurs in relation to the harvest time of tubers. Cultivation temperature greatly affected the growth of the plant. The number of leaves a...
Five new ellagitannins, platycaryanins A (27), B (26), C (30), and D (25), and platycariin (31), and a new complex tannin, strobilanin (32), have been isolated from the fruits and bark of Platycarya strobilacea SIEB, et ZUCC, (Juglandaceae), together with twenty-six known compounds. On the basis of spectroscopic and chemical evidence, platycaryanin...
Fifty-six tannins were evaluated for their inhibitory effects against protein kinase C (PKC). Ellagitannins and complex tannins were found to be potent inhibitors of PKC, while gallotannins and condensed tannins, having a relatively large number of phenolic hydroxy groups, showed moderate inhibitory effects on PKC. Phorbol displacement assay sugges...
Further evaluation of tannins as anti-HIV agents indicates that these compounds inhibited HIV replication only slightly in the absence of toxicity (therapeutic index ≤ 5). In addition, no correlation was found between inhibition of reverse transcriptase and of HIV in cell culture.
Fifty-seven tannins and related compounds, including gallotannins, ellagitannins, and condensed and complex tannins, were evaluated for their cytotoxicities against human tumor cell lines, including malignant melanoma, lung carcinoma, ileocecal adenocarcinoma, epidermoid carcinoma, malignant melanoma, and medulloblastoma cell lines. Among them, che...
Two new hydrolysable tannins, alnusjaponins A and B, were isolated from the leaves of Alnus japonica, along with 12 known hydrolysable tannins and related compounds, namely 5-O-galloyl-(−)-shikimic acid, 2,3-(S)-hexahydroxydiphenoyl-d-glucose, 4,6-di-O-galloyl-d-glucose, 1,4-di-O-galloyl-β-d-glucose, 4,6-(S)-valoneoyl-d-glucose, strictinin, gemin D...
A study was performed to investigate the haemodynamic effects of magnesium lithospermate B in rats with renal failure. Urinary excretion of sodium and potassium was significantly increased by administration of magnesium lithospermate B. Blood pressure was significantly lower in the magnesium lithospermate B-treated group, compared with the control...
Chemical examination of the leaves of Pithecellobium lobatum has led to the isolation and characterization of five flavan-3-ol derivatives including new flavan-3-ol gallates, gallocatechin 3′- and 4′-O-gallates and gallocatechin 7,3′- and 7,4′-di-O-gallates (almost racemic), which occur as equilibrium mixtures. Examination of the pods afforded thre...
To evaluate the antihypertensive effect of magnesium lithospermate B isolated from Salviae miltiorrhizae radix, determinations of blood pressure and urinary excretions of sodium, potassium, prostaglandin E2 (PGE2) and kallikrein, which have been proposed to play an important role in the regulation of blood pressure, were made in rats with sodium-in...
From the fresh leaves of Carpinus laxiflora (Betulaceae), two new hydrolyzable tannins, carpinusin (2) and carpinusnin (3), have been isolated, together with thirteen known hydrolyzable tannins and related compounds, and their structures were elucidated on the basis of physico-chemical evidence.
A novel ellagitannin, hirsunin, was isolated from the leaves of Alnus hirsuta var. microphylla and the structure which consists of diarylheptanoid glycoside (oregonin) and ellagitannin (praecoxin A) moieties connected through an ester linkage has been elucidated. Furthermore, the occurrence of the seven known hydrolysable tannins, pedunculagin, pra...
The dehydroellagitannins having a dehydrohexahydroxydiphenoyl ester group in the molecule were found to undergo highly regio- and stereospecific condensation with acetone in the presence of ammonium ion under almost neutral conditions. This reaction was successfully applied to high-performance liquid chromatographic analysis to detect the dehydroel...
Four new tetragalloylquinic acids, 3,5-di-O-galloyl-4-O-digalloylquinic acid (2), 3,4-di-O-galloyl-5-O-digalloylquinic acid (3), 3-O-digalloyl-4,5-di-O-galloylquinic acid (4), and 1,3,4,5-tetra-O-galloylquinic acid (5), were isolated and characterized from a commercial tannic acid as a new class of human immunodeficiency virus (HIV) reverse transcr...
Reaction of dehydroellagitannins (e.g.1) with L-cysteine methyl ester (5) at room temperature yielded the condensation products (e.g.3 and 4), together with a partial hydrolysate (e.g.2), while heating the mixture at 80 °C afforded 4 and the hydrolysate(2) in fairly good yields. In addition, reduction of a dehydrohexahydroxydiphenoyl ester group to...
Continuing chemical examination of black tea has led to the isolation of three novel fermentation products, theogallinin (1), theaflavonin (10) and desgalloyl theaflavonin (11). The structure of 1 was established on the basis of physico-chemical evidence to be a condensation product linked through pyrogallol-pyrogallol rings in theogallin (2) and (...
Six new complex tannins, guajavins A (5) and B (1), psidinins A (9), B (11) and C (13), and psiguavin (15), together with a variety of condensed, hydrolyzable and complex tannins, have been isolated from the bark of Psidium guajava L. (Myrtaceae). On the basis of chemical and spectroscopic evidence, the structures of guajavins and psidinins were es...
Two proanthocyanidins named samarangenins A (1) and B (2) have been isolated, together with a variety of flavan-3-ols, proanthocyanidins and hydrolyzable and complex tannins, from the leaves of Syzygium samarangens (BLUME) MERR. et PERRY and S. aqueum (BURM F.) ALSTON (= Eugenia aquea BURM.) (Myrtaceae). Compounds 1 and 2 were characterized on the...
Lagerstannins A (6), B (11) and C (8), ellagitannins having a gluconic acid core, have been isolated from the fruits and leaves of Lagerstroemia speciosa (L.) Pers. (= L. flos-reginae Retz.) (Lythraceae). On the basis of chemical and spectroscopic evidence, their structures were established as 2,3;4,6-bis-O-(S)-hexahydroxydiphenoyl-D-gluconic acid...
A chemical investigation of the roots of Euphorbia fischeriana has led to the isolation of three novel gallotannins, 1,3,6-tri-O-, 1,2,6-tri-O- and 1,2,3,6-tetra-O-galloyl-β-d-allopyranoses, together with ellagitannins (corilagin, sanguiin H-5 and tercatain) and 3,4,6-tri-O-galloyl-d-glucose. The structures of these compounds were established from...
The renal responses of magnesium lithospermate B were investigated in the presence or absence of pretreatment with the converting enzyme (kininase II) inhibitor, captopril, in rats with adenine-induced renal failure. Magnesium lithospermate B (10 mg/kg body weight) caused a marked increase in the levels of the renal functional parameters (glomerula...
Magnesium lithospermate B and adenine were given simultaneously to rats p.o. in order to investigate their renal effects. In rats given magnesium lithospermate B at a dose of 5 mg/kg body weight/day for 12 or 24 days, glomerular filtration rate, renal plasma flow and renal blood flow were increased significantly. A significant increase in renal fun...
The effects of each of several tannins purified from Rhei Rhizoma on serum constituents were investigated in rats with adenine-induced renal failure. Blood levels of urea nitrogen, methylguanidine (MG), and guanidinosuccinic acid (GSA) were significantly decreased in rats given (-)-epicatechin 3-O-gallate at a dose of 2.5, 5 or 10 mg/kg body weight...
To avoid tautomerism in the hydrolyzable tannins which lack an acyl group at the glucose C-1 position, a new method for the protection fo the C-1 atom has been developed. That is reaction of the tannins with p-anisidine in the presence of acetic acid, followed by sodium cyanoborohydride reduction, afforded, without notable hydrolysis of ester bonds...
A chemical examination of Magnoliae Cortex produced in China (Magnolia officinalis REHD. et WIL S., Magnoliaceae) has led to the isolation of eighteen new lignans and related compounds [four monoterpenyl-lignans : piperitylmagnolol (3), dipiperitylmagnolol (4), piperitylhonokiol (5) and bornylmagnolol (6); seven lignans : magnaldehydes B(8), C(9),...
A chemical investigation of tannins in three Euphorbia species (E. helioscopia, E. jolkini and E. supina) has led to the isolation and characterization of four new hydrolyzable tannins, named supinanin (15), euphorscopin (16), euphorhelin (17) and jolkianin (18), together with fourteen known compounds (1-14). On the basis of chemical and spectrosco...
Further chemical work on tannins in the leaves of Lagerstroemia flos-reginae RETZ. (Lythraceae) has resulted in the isolation of new monomeric (flosin B) and dimeric ellagitannins (reginins C and D), together with pterocarinin A (1) and 5-desgalloylpterocarinin A (2). On the basis of chemical and spectroscopic evidence, the structure of flosin B wa...
When the axillary buds of Gentiana scabra BUNGE var. buergeri MAXIM. were cultured on Murashige-Skoog (MS)medium supplemented with a combination of gibberellin A3 (GA) and 6-benzylaminopurine (BAP) (1mg/l each) at 25°C under 16h light conditions for 60d, the direct multiple shoot formation (18.5 shoots per axillary bud) occurred. The MS medium cont...
Aconitum spp., aconite or monkshood, is a perennial herb of the family Ranun-culaceae. It is erect and grows to a height of about 1 m. The leaves are deep green and lustrous, and purple flowers bloom in the autumn. The aconite consists of both parent and daughter roots. Both are obconical in shape, dark brown in color, from 4 to 10 cm in length and...
Continuing chemical examinatino on tannins of Combretaceous Plants has led to the isolation of four new ellagitannins, calamansanin and calamanins A, B, and C, together with ten structurally known tannins and related compounds, from the leaves of Terminalia calamansanai (BLANCO) ROLFE. On the basis of chemical and spectroscopic evidence, the struct...
Three novel complex tannins (flavano-ellagitannins), anogeissinin (9) and anogeissuisins A (10) and B (11), have been isolated from the bark of Anogeissus acuminata (ROXB. ex DC.) GUILL. et PERR. var. lanceolata WALL. ex CLARKE (Combretaceae), together with eight known C-glycosidic hydrolyzable tannins. On the basis of spectroscopic and chemical ev...
Two novel hydrolyzable tannins, alienanins A (5) and B (13), have been isolated from the leaves of Quercus aliena Blume (Fagaceae), and their structures were elucidated on the basis of chemical and spectroscopic evidence to be dimeric C-glycosidic ellagitannins in which the hexahydroxydiphenoyl ester group is linked to the C-glycosidic C-1 atom thr...
A chemical examination of Chinese rhubarb has led to the isolation of two new chromone glucosides. On the basis of chemical and spectroscopic evidence, their structures were established as aloesone 7-O-β-d-glucopyranoside and 2-methyl-5-(2′-oxo-4′-hydroxypentyl)-7-hydroxychromone 7-O-β-d-glucopyranoside.
Two new anthocyanins, cyanidin and peonidin 3-gentiobioside acylated with sinapic acid, have been isolated from the tuber of Dioscorea alata L. ‘King yam’ originated from Sri Lanka. These structures are elucidated by spectroscopic methods.
A series of flavan-3-ols and procyanidins, possessing a carboxymethyl group, and a procyanidin tetramer have been isolated from the fern, Davallia divaricata. The structures were characterized on the basis of chemical and spectral evidence.
Four new gallotannins, 3,4-di-O-, 4,11-di-O- and 3,4,11-tri-O-galloylbergenins and 4-O-galloylnorbergenin, have been isolated from the bark and leaves of Mallotus japonicus, and their structures elucidated on the basis of chemical and spectroscopic evidence. In addition, the occurrence of 13 known gallotannins and related compounds was demonstrated...
Chemical investigation of Euphorbia thymifolia has led to the isolation and characterization of a new hydrolysable tannin named isomallotinic acid, in addition to 15 known tannins. The structure of isomallotinic acid was established on the basis of spectroscopic and chemical evidence.
— Renal responses to magnesium lithospermate B isolated from Salviae miltiorrhizae radix were examined in normal rats. Urinary sodium, potassium, prostaglandin E2 and kallikrein excretion was significantly increased after magnesium lithospermate B administration, whereas excretion of urinary 6-keto-prostaglandin F1α and thromboxane B2 was unchanged...
The effect of magnesium lithospermate B on the renal responses of rats with renal failure was investigated in the presence and absence of pretreatment with the kallikrein inhibitor, aprotinin. Magnesium lithospermate B caused a marked increase in the levels of the renal functional parameters (glomerular filtration rate, renal plasma flow and renal...
The unique hydrated biscyclohexenetrione structures (1)–(4) of carpinins A–D, the metabolites of hexahydroxydiphenic acid esters (ellagitannins) isolated from the leaves of Carpinus japonica, are described.
The effects of persimmon tannin on pathophysiological changes in stroke-prone spontaneously hypertensive rats (SHRSP) were investigated. When the persimmon tannin was chronically ingested by SHRSP, the life span was significantly prolonged, yet the effect on blood pressure was slight. The incidences of brain hemorrhage and infarction were also sign...
The anther segments of Paeonia suffruticosa Andrews were cultured for callus formation on MS medium supplemented with 2,4-D and BAP(each 1 mg/l) in the dark at 25°C for six weeks. Gallic acid, methyl gallate, ethyl gallate and 1,2,3,4,6-penta-O-galloyl-β-D-glucose were isolated from the ethanol extract of callus, and paeoniflorin was identified. A...
Urinary excretion of prostaglandin E2 showed a significant increase following administration of magnesium lithospermate B [1] in rats with renal failure. In contrast, that of thromboxane B2 showed a significant decrease, indicating the improvement of renal failure.
The clonal propagation of Atractylodes avata and A. japonica by tip tissue culture and the subsequent establishment of adult plants is described. The quantitative analysis of the major biologically active constituent in the rhizone of clonally propagated plants was performed, and atractylon was identified by GLC after 4 months of cultivation
The structures of the C-glycosidic ellagitannins, castalagin, vescalagin, casuarinin and stachyurin, have been revised to 1-4 respectively, on the basis of two-dimensional nuclear Overhauser effect (NOE) spectroscopy and NOE difference spectroscopy. Furthermore, the structures of some related C-glycosidic tannins were re-examined by using similar t...
Together with eleven known compounds (1-11), seven new tannins, 3-desgalloylterchebin (12), macaranins A, B and C, and macarinins A, B and C, have been isolated from the leaves of Macaranga sinensis (BAILL.) MUELL.-ARG. (Euphorbiaceae). Macaranins A (14), B (13) and C (17) have been determined on the basis of chemical and spectroscopic evidence to...
A chemical examination of the tannin ingredients in the leaves of the wood oil tree, Aleurites fordii HEMSLEY (Euphorbiaceae), has led to the isolation of three new ellagitannins named aleurinins A (4), B(5) and C(6), together with corilagin (1), geraniin (2) and chebulagic acid (3). on the basis of chemical and spectroscpic evidence, the structure...
Together with ten hydolyzable tannins and related compounds (1-10), three novel dimeric ellagitannins, excoecarianin (11), and excoecarinins A (13) and B (16), possessing a dehydrohexahydroxydiphenoyl or an elaeocarpusinoyl group, have been isolated from the leaves of Excoecaria kawakamii HAYATA (Euphorbiaceae). The structures of these tannins were...
A chemical examination of polyphenols in Euphorbia helioscopia L. (Euphorbiaceae) has led to the isolation of four new hydrozable tannins named helioscopinins A (10) and B (9), and helioscopins A (11) and B (12), together with eight known tannins (1-8). On the basis of chemical and spectroscopic evidence, the structures of compounds 9-12 were estab...
Proanthocyanidins containing flavan-3-ol (epiafzelechin and epicatechin) units with an abnormal 2S-configuration have been isolated from the pods of Cassia fistula L. and the bark of C. javanica L. (Leguminosae), together with common flavan-3-ols and proanthocyanidins The structures of these compounds have been established on the basis of chemical...
Some novel reactions of dehydrohexahydroxydiphenic acid esters [e.g., geraniin (1)] with bases are presented. Namely, treatment of 1 with triethylamine or sodium benzenesulfinate in acetonitrile caused a benzylic acid-type rearrangement to yield a brevifolin carboxylic acid derivative (3). On the other hand, treatment of 1 with pyridine gave a tetr...
A chemical examination of mylobalans (the fruits of Terminalia chebula RETZ., Combretaceae) has led to the isolation and characterization of punicalagin (1), terflavin A (2) and a new ellagitannin named terchebulin (3), which possesses a anovel tetraphynylcarboxylic acid (terchebulic acid) moiety. Furthermore, from the leaves of T. chebula, a serie...
A chemical examination of the polyphenolic constituents of the fern, Dicranopteris pedata HOUTT., has led to the isolation of eight new proanthocyanidins possessing a doubly-linked (A-type) unit, together with known flavan-3-ols and proanthocyanidins. On the basis of chemical and spectroscopic evidence, they are characterized as epiafzelechin-(4β→8...
A chemical examination of the tannins in the leaves of Macaranga tanarius (L.) MUELL. et ARG. (Euphorbiaceae) has led to the isolation of seven new hydrolyzable tannins (22-28), together with twenty-one known tannins (1-21). On the basis of chemical and spectroscopic evidence, the structures of compounds 22-28 were established as 1, 4-di-O- galloyl...
A chemical investigation of the leaves of Cornus officinalis has led to the isolation and characterization of a novel gallotannin, 1,7-di-O-gallloyl-d-sedoheptulose, in addition to six galloylglucoses and five ellagitannins. The structure of the new compound was established on the basis of spectroscopic and chemical evidence. This is the first gall...
From tissue callus of Panax japonicus grown in South Kyushu, two ginseng dammarane saponins, ginsenosides Rg1 and Re, and an oleanane saponin (desglucosylchikusetsusaponin-IV) together with chikusetsusapon-in-IV were isolated.
Five phenol glucoside gallates were isolated from Mallotus japonicus, and their structures characterized by chemical and spectroscopic means as 4-hydroxy-2-methoxyphenol 1-O-β-d-(6′-O-galloyl)glucoside, 4-hydroxy-3-methoxyphenol 1-O-β-d-(2′,6′-di-O-galloyl)glucoside, 4-hydroxy-3-methoxyphenol 1-O-β-d-2′,3′,6′-tri-O-galloyl)glucoside, 3,4,5-trimetho...
Two new ellagitannins, alnusnins A and B, have been isolated from the leaves of Alnus sieboldiana (Betulaceae) and characterized as 1-O-galloyl-2,3-(S)-hexahydroxydiphenoyl-4,6-(S)-tergalloyl-β-d-glucose and 2,3-(S)-hexahydroxydiphenoyl-4,6-(S)-tergalloyl-d-glucose, respectively, by chemical and spectral evidence. The occurrence of eight known tann...
Callus formation from leaf segments of Rehmannia glutinosa var. purpurea was obtained after the addition of 1 mg/1 2,4-D. When the calli were subcultured embryogenesis occurred. Mature somatic embryos developed normal shoots when transferred to 1/2 MS medium containing 1 mg/1 GA BAP. Root differentiation were cultured in a MS liquid medium suppleme...
Four flavan-3-ol glycosides and three proanthoeyanidin glycosides have been isolated from the fern, Davallia divaricata, together with procyanidins B-1 and B-2 and a trimeric procyanidin. All of these glycosides have been shown to possess an allopyranose moiety. The structures were elucidated on the basis of chemical and spectroscopic evidence.
An attempt was made to isolate the active component which exhibits an improving effect on renal function from Salviae Miltiorrhazae Radix (Chinese crude drug). Systematic isolation from aqueous extract of Salviae Miltiorrhizae Radix was carried out, and Compound 1 was found to be more effective than any of the other constituents in improving renal...
The effect of magnesium lithospermate B isolated from Salviae miltiorrhizae Radix on excretion of urinary arachidonate metabolites was examined in both normal rats and those given adenine. Urinary excretion of prostaglandin E2 (PGE2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) decreased while urinary thromboxane B2 (TXB2) excretion increa...
A chemical examination of the bark of Mallotus japonicus (Thunb.) Mueller-Arg. (Euphorbiaceae) has led to the isolation of five new hydrolyzable tannins (16-20), together with fourteen known tannins (1-14). On the basis of chemical and spectroscopic evidence, the structures of compounds 16 and 17 were established as 1,2-di-O-galloyl-3,6-(R)-hexahyd...
The involvement of prostanoids in the improvement of adenine-induced renal failure in rats by magnesium lithospermate B was studied. After intraperitoneal administration of magnesium lithospermate B to renal failure rats, the levels of glomerular filtration rate, renal plasma flow and renal blood flow were increased. Urinary excretions of prostagla...
Previously we reported the antitumor activity of 4 kinds of Chinese herbs: A. capillaris, S. doederleinii, A. macrocephala and S. subprostrata. Evidence has been also presented that A. capillaris shows the activity mainly through a direct tumoricidal action and the others display the activity through the enhancement of tumor-immune response. The pr...
DNA breakage by flavan-3-ols and procyanidins in the presence of cupric ion was investigated by gel electrophoretic and computer analysis. Flavan-3-ols and procyanidins cleaved λ-DNA in a concentration-dependent manner. The DNA-breaking activity was remarkably enhanced approximately in connection with the increase of the number of dihydroxy or trih...
Virus free plants of Rehmannia glutinosa Libosch. var. purpurea Makino were obtained through meristem tip tissue cultures from plants infected with a mixture of tabocco mosaic virus(TMV), a member of the carlavirus group, and an unknown spherical virus. The re-infection rate of the virus free plants by TMV in the field was determined by enzyme link...
A chemical examination of the polypenolic constituents in commercial oolong tea has led to the isolation of a new-flavan-3-ol, two novel dimeric flavan-3-ols named oolonghomobisflavans A and B eight new proanthocyanidins, together with twenty-one known polyphenols including proanthocyanidins, hydrolyzable tannins and red pigments. On the basis of c...