Masayuki Yoshikawa

Kyoto Pharmaceutical University

The methanol extract from the leaves of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae), popularly known as mate, maté, or yerba maté, inhibits the intracellular triglyceride accumulation in HepG2 cells and suppresses the plasma triglyceride elevation in olive oil-treated mice. Three new triterpene saponins, termed mateosides I (1), II (2), and III...

Zingiber cassumunar is widely distributed in Asia, and its rhizomes are used for asthma treatment in traditional medicine and as a spice. Five new phenylbutanoids, cassumunols I–M (1-5), were isolated from Z cassumunar rhizomes collected in Thailand, and their structures were characterized on the basis of physiochemical and chemical evidence.

A methanol extract from the underground part of Calanthe discolor Lindl. (Orchidaceae) demonstrated significant proliferative activity on human hair follicle dermal papilla cells (HFDPC, % of control: 120.8 ± 0.2%) at 100 µg/mL against HFDPC. Through bioassay-guided separation of the extract, a new indole glycoside named 6′-O-β-D-apiofuranosylindic...

During our studies characterizing functional substances from food resources for the prevention and treatment of lifestyle-related diseases, we isolated the active constituents, salacinol ( 1 ) and neokotalanol ( 4 ), and related thiosugar sulfoniums, from the roots and stems of the genus Salacia plants [Celastraceae (Hippocrateaceae)] such as Salac...

The number of diabetes mellitus and borderline diabetes cases is increasing and poses a serious problem worldwide. Plants of the genus Salacia are known to have α-glucosidase inhibitory activity and to lower postprandial hyperglycemia. Two randomized, double-blind, placebo-controlled clinical trials were conducted to evaluate the efficacy of Salaci...

The article Inhibition of melanin production by anthracenone dimer glycosides isolated from Cassia auriculata seeds, written by Weicheng Wang, Yi Zhang, Souichi Nakashima, Seikou Nakamura, Tao Wang, Masayuki Yoshikawa and Hisashi Matsuda.

Three new acylated phenylethanoid glycosides, kurroaosides A (14), B (15), and C (16), and a new acylated cucurbitane-type triterpene glycoside, kurroaoside D (17), were isolated from a methanol extract of the rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae) along with 29 known isolates including 10 acylated phenylethanoid glycosides...

Seven new acylated iridoid glycosides, picrorhizaosides A-G (1-7), were isolated from the methanol extract of the rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae), in addition to six known iridoid glycosides (8-13). The structures of these new iridoids, including their stereochemistry, were determined based on chemical and physicochem...

Dimeric sesquiterpene thioalkaloids from the rhizomes of Nuphar pumilum exhibited immunosuppressive effects using a sheep erythrocyte plaque forming cell (PFC) assay, as well as an anti-metastasis effect, and rapid apoptosis-inducing effects in tumor cell lines. In particular, dimeric sesquiterpene thioalkaloids with a hydroxy group (6-hydroxythiob...

An Orobanchaceae plant Cistanche tubulosa (SCHENK) WIGHT (Kanka-nikujuyou in Japanese), which is one of the authorized plant resources as Cistanches Herba in both Japanese and Chinese Pharmacopoeias, is a perennial parasitic plant growing on roots of sand-fixing plants. The stems of C. tubulosa have traditionally been used for treatment of impotenc...

Using a recently developed analytical protocol, distributions of 5 aporphine alkaloids, nuciferine (1), nornuciferine (2), N-methylasimilobine (3), asimilobine (4), and pronuciferine (5), and 5 benzylisoquinoline alkaloids, armepavine (6), norarmepavine (7), N-methylcoclaurine (8), coclaurine (9), and norjuziphine (10), in lotus flowers (the flower...

The methanol extract of Cassia auriculata seeds was found to inhibit melanogenesis in B16 melanoma 4A5 cells under conditions of theophylline stimulation. Two new phlegmacin-type anthracenone dimer glycosides, auriculataosides A and B, were isolated from the active methanol fraction, and their inhibitory effects were observed in the concentration r...

The antidiabetic effects of a hot water extract of the stems of Salacia chinensis (SCE) were evaluated in vivo in ob/ob mice (genetically obese hyperglycemic mice). Administration of dietary feed containing 0.20 and 0.50% of SCE for 23 days to ob/ob mice significantly suppressed the elevation of both blood glucose and HbA1c levels, without signific...

Multi-drug resistance (MDR) is a fatal problem in cancer chemotherapy. MDR is caused the overexpression of ATPbinding cassette (ABC) transporters and mutations in tumor suppressor genes and oncogenes. We focused on Nuphar plants which have been traditionally used as foods. Sesquiterpene alkaloids (1–3) were isolated from N. japonicum, and dimeric s...

A new acylated oleanane-type triterpene oligoglycoside, floratheasaponin K (1), was isolated together with 11 known compounds including floratheasaponins D (2)–G (5), and I (6), chakasaponin V (7), and assamsaponin E (8) from the flower buds of Camellia sinensis cultivated in India. The chemical structure of floratheasaponin K (1) was elucidated on...

Frankincense and myrrh have been used as incense in religious and cultural ceremonies since the beginning of written history. Their common medicinal properties are used in the treatment for inflammatory conditions, some cancerous diseases, and wound healing. In the course of our characterization of the anti-inflammatory constituents from frankincen...

The methanolic extract [inhibition (%): 61.2±3.8 (p<0.01) at 100 μg/mL] and its EtOAc-soluble fraction [inhibition (%): 82.5±1.7 (p<0.01) at 100 μg/mL1 from the sclerotia of Inonotus obliquus collected in Japan significantly inhibited invasion of human fibrosarcoma HT1080 cells through matrigel-coated filters. In addition, the methanolic extract si...

Acylated oleanane-type triterpene saponins, namely chakasaponins I (1) and II (2), floratheasaponin A (3), and their analogs, together with catechins—including (–)-epigallocatechin 3-O-gallate (4), flavonoids, and caffeine—have been isolated as characteristic functional constituents from the extracts of “tea flower”, the flower buds of Camellia sin...

A quantitative analytical method for five aporphine alkaloids, nuciferine (1), nornuciferine (2), N-methylasimilobine (3), asimilobine (4), and pronuciferine (5), and five benzylisoquinoline alkaloids, armepavine (6), norarmepavine (7), N-methylcoclaurine (8), coclaurine (9), and norjuziphine (10), identified as the constituents responsible for the...

We review the biofunctional effects of the flower buds of Camellia sinensis and C. sinensis var. assamica, such as antihyperlipidemic, antihyperglycemic, antiobesity, and gastroprotective effects in vivo, and antiallergic, pancreatic lipase inhibitory, and amyloid β (Aβ) aggregation inhibitory activities in vitro. Although the biofunctional effects...

A new benzocoumarin glycoside, cassiaglycoside I (1), a new naphthol glycoside, cassiaglycoside II (2), a new chromon glycoside, cassiaglycoside III (3), a new phenylethyl glycoside, cassiaglycoside IV (4), were isolated from the seeds of Cassia auriculata, together with seven known constituents. The chemical structures of four new constituents wer...

Seven oleanane-type triterpene saponin bisdesmosides, perennisaponins N–T (1–7), were newly isolated from a methanol extract of daisy, the flowers of Bellis perennis L. (Asteraceae). The structures were determined based on chemical and physicochemical data and confirmed using previously isolated related compounds as references. The isolates, includ...

Two new dammarane-type triterpene oligoglycosides, bacomosaponins A and B, and three new phenylethanoid glycosides, bacomosides A, B1, and B2, were isolated from the whole plant of Bacopa monniera Wettst. The chemical structures of the new constituents were characterized on the basis of chemical and physicochemical evidence. In the present study, b...

Four new alkaloids, hemerocallisamines IV-VII, were isolated from the methanol extract of flower buds of daylily. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The absolute stereochemistry of the hemerocallisamines IV-VI was elucidated by the application of the modified Mosher's...

Mast cells and basophils play important roles in both immediate- and late-phase reactions of type 1 allergy. Histamine, which is released from mast cells and basophils stimulated by an antigen or degranulation inducers, is usually determined as a degranulation marker in experiments on immediate allergic reactions in vitro. β-Hexosaminidase is also...

A methanol extract of the flowers of Narcissus tazetta var. chinensis Roem. (Amaryllidaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, four new phenylethanoid glycosides, tazettosides A-D (1-4), and a new phenylpropanoid glycoside, tazettoside E (5), were isolated al...

The first total synthesis of the 7,7-dimethylaporphinoid, 4,5-didehydroguadiscine (6), originally isolated from the stems and roots of Hornschuchia oblique (Annonaceae), was achieved by the condensation of homopiperonylamine (7) with an α,α-dimethylphenylacetic acid derivative (8) and subsequent Pschorr reaction of the resulting benzylisoquinoline...

Five new diterpene glycosides, auricuosides I (1), II (2), III (3), IV (4), and V (5), a new flavonol glycoside, auricuoflavonoside I (6), and a new megastigmane glycoside, auricuomegastigmane I (7), were isolated from the seeds of Cassia auriculata, together with 11 known constituents. The chemical structures of seven new constituents were charact...

The methanol extract from Bellis perennis (Asteraceae) flowers was found to promote collagen synthesis in normal human dermal fibroblasts (NHDFs). Seven oleanane-type triterpene saponins, perennisosides XIII-XIX, and two known saponins, bellissaponins BS5 and BS9, were isolated from the methanol extract. The structures were determined based on chem...

A methanol extract of everlasting flowers of Helichrysum arenarium L. Moench (Asteraceae) was found to inhibit the increase in blood glucose elevation in sucrose-loaded mice at 500 mg/kg p.o. The methanol extract also inhibited the enzymatic activity against dipeptidyl peptidase-IV (DPP-IV, IC50 = 41.2 μg/ml), but did not show intestinal α-glucosid...

The methanolic extract of Lawsonia inermis L. (henna) showed significant inhibitory activity toward melanogenesis in B16 melanoma 4A5 cells. Among the constituents isolated from the methanolic extract, luteolin, quercetin, and (±)-eriodictyol showed stronger inhibitory activity than the reference compound, arbutin. Several structure-activity relati...

A new monoterpene glycoside, floralalbiflorin I (1), and a new flavonol glycoside, lactifloraoside I (2), were isolated from the flowers of Paeonia suffruticosa and Paeonia lactiflora (Paeoniaceae) together with 28 known compounds. The chemical structures of the isolated compounds were elucidated on the basis of chemical and physicochemical evidenc...

The antidiabetic effect of a hot water extract of stems of Salacia chinensis (SCE) was evaluated in vivo in KK-Ay mice, a typical type 2 diabetes mellitus mice model. Administration of CE-2 dietary feed containing 0.25 and/or 0.50% of SCE for three weeks to KK-Ay mice significantly suppressed the elevation of both blood glucose and HbA1c levels wit...

Eight new acylated oleanane-type triterpene oligoglycosides, floraassamsaponins I, II, III, IV, V, VI, VII, and VIII, were isolated from the flower buds of Camellia sinensis var. assamica. The chemical structures of new constituents were characterized on the basis of chemical and physicochemical evidence. In the present study, floraassamsaponins I...

IntroductionStems and roots of Salacia genus plants have been used in Ayurveda as a specific remedy for early stage diabetes. Previous investigations identified four sulphonium sulphates, that is, salacinol (1), kotalanol (3), ponkoranol (5) and salaprinol (7), as the compounds responsible for the anti-diabetic activity. Their desulphonates (2, 4,...

Three new megastigmane glycosides named floraosmanosides I-III and a new γ-decalactone named floraosmanolactone I together with 16 known constituents were isolated from the flowers of Osmanthus fragrans var. aurantiacus cultivated in Guangxi Zhuang Autonomous Region, China. The chemical structures of the new compounds were elucidated on the basis o...

The methanolic extract from the dried rhizomes of Curcuma comosa cultivated in Thailand was found to inhibit the release of β-hexosaminidase as a maker of degranulation from rat basophil leukemia (RBL-2H3) cells. Two new diarylheptanoids, diarylcomosols IV and V, were isolated from the methanolic extract. The chemical structures of the new compound...

An 80% aqueous acetone extract of Cassia auriculata leaves was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the 80% aqueous acetone extract, we isolated a new benzocoumarin glycoside, avaraoside I (1), and a new flavanol dimer, avaraol I (2), together with 29 known constituent...

Phytochemical investigations of the CH2Cl2/MeOH (1:1) extract of air-dried aerial parts of Chiliadenus montanus afforded metabolites (1–8), in addition to eight previously reported compounds, two of which were isolated for the first time as free acids. Structures were established by spectroscopic methods, including HREIMS, 1H, 13C, DEPT, 1H–1H COSY...

The present invention provides a fat metabolism improving agent comprising rose hips or an extract therefrom as an active ingredient. This fat metabolism improving agent is very safe and has a superior body weight reducing effect.

Potent ligands of peroxisome proliferator-activated receptor γ (PPARγ) such as thiazolidinediones (pioglitazone, troglitazone, etc.) improve insulin sensitivity by increasing the levels of adiponectin, an important adipocytokine associated with insulin sensitivity in adipose tissue. Several constituents from medicinal plants were recently reported...

A methanol extract from the tuberous roots of Potentilla anserina (Rosaceae) exhibited hepatoprotective effects against D-galactosamine (D-GalN)/lipopolysaccharide-induced liver injuries in mice. Six triterpene 28-O-monoglucopyranosyl esters, potentillanosides A-F, were isolated from the extract along with 32 known compounds, including 15 triterpen...

A rare glutamine derivative, hemerocallisamine I (1), was isolated from the methanolic extract of the flower buds of daylily, together with a new pyrrole alkaloid hemerocallisamine II (2) and a new γ-lactam derivative, hemerocallisamine III (3). The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemica...

Three new terpenoid derivatives, canangaterpenes IV-VI, were isolated from the flower buds of Cananga odorata, cultivated in Thailand, together with eight known flavonoids. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated compounds on aldose re...

Acylated phenylethanoid glycosides, echinacoside (1) and acteoside (2), principal constituents in stems of Cistanche tubulosa (Orobanchaceae), inhibited the increase in postprandial blood glucose levels in starch-loaded mice at doses of 250-500 mg/kg p.o. These compounds (1 and 2) also significantly improved glucose tolerance in starch-loaded mice...

A methanol extract of the flower buds of Chimonanthus praecox (L.) Link (Calycanthaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, five dimeric pyrrolidinoindoline alkaloids and four sesquiterpenes were isolated, together with 16 known compounds. Among them, (-)-chim...

The methanolic extract from the flower buds of Cananga odorata showed an inhibitory effect on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extract, two new lignan dicarboxylates, canangalignans I and II, three new terpenoids, canangaterpenes I, II, and III, and eight known compounds were isolated. The...

Seven new acylated sucroses, mumeoses P-V, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. Moreover, mumeoses C, D, and R, were shown to substantially inhibit aldose reductase.

Salacinol was isolated as the first naturally occurring sulfonium type α-glucosidase inhibitor from Salacia reticulata, a large woody, climbing plant widely distributed in Sri Lanka and South India, in 1997. This compound presents a quite unique zwitterionic sulfonium sulfate structure and its α-glucosidase inhibitory activity (in vitro) was reveal...

Using the recently developed two analytical protocols, distributions were analyzed of five catechins (1-5), ten flavonoids (6-15), caffeine (16), and nine saponins (17-25) in 12 samples of flower buds of Camellia sinensis (L.) O. Kuntze, collected at different points in Taiwan. Characteristic tendencies with respect to the distribution of these con...

A simultaneous quantitative analytical method for 15 major polyphenols, e.g. five catechins (1-5) and 10 flavonols (6-15), as functional constituents in the extracts of "tea flowers", the flower buds of Camellia sinensis (Theaceae), has been developed. The content of caffeine (16), which showed similar chromatographic behaviour under the analytical...

The methanolic extract from the dried rhizomes of Curcuma comosa cultivated in Thailand was found to inhibit melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extract, three new diarylheptanoids, diarylcomosols I-III, were isolated together with 12 known diarylheptanoids. Their chemical structures were eluc...

In a previous study, retrofractamide A from the fruit of Piper chaba was shown to promote adipogenesis in 3T3-L1 cells. In the present study, retrofractamide A and its derivatives were synthesized, and their adipogenetic effects in 3T3-L1 cells were examined. Among the tested compounds, an amide composed of 9-(3',4'-methylenedioxyphenyl)-nona-2E,4E...

Further investigation on the whole herbs of Sinocrassula indica (Crassulaceae) led to the isolation of four new acylated flavonol bisdesmosides, sinocrassosides A13 (1), B6 (2), B7 (3), and D4 (4), together with kaempferol 3-O-β-d-(6-O-acetyl)glucopyranosyl-7-O-α-l-rhamnopyranoside (5). Their structures were established by spectral and chemical met...

An ultra performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (QTOF/MS) method is established for the rapid analysis of isoflavones, saponins and flavones in 16 samples originated from the flowers of Pueraria lobata and P. thomsonii. A total of 25 isoflavones, 13 saponins and 3 flavones were identified b...

Six dihydroisocoumarin glycosides, florahydrosides I and II, thunberginol G 8-O-β-d-glucopyranoside, thunberginol C 8-O-β-d-glucopyranoside, 4-hydroxythunberginol G 3'-O-β-d-glucopyranoside, and thunberginol D 3'-O-β-d-glucopyranoside, have been isolated from the flowers of Hydrangea macrophylla Seringe var. thunbergii Makino (Saxifragaceae) togeth...

The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang Province, China, showed an inhibitory effect on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. From the methanolic extract, five acylated sucroses, mumeoses A-E, and three acylated quinic acid analogs, 5-O-(E)-p-coumaroylquinic acid ethyl ester, and...

Two new acylated dolabellane-type diterpenes, nigellamines B3 (9) and D (10), were isolated from Nigella sativa (Ranunculaceae) seeds using column chromatography and preparative HPLC. Their structures were determined based on chemical and physicochemical evidence, and confirmed using previously isolated related compounds as reference. Of the seed c...

In our previous study, piperlonguminine from the fruit of Piper chaba was reported to promote adipogenesis in 3T3-L1 cells like the peroxisome proliferator-activated receptor-γ (PPARγ) agonist, troglitazone. In the present study, the mode of action of piperlonguminine in cells was examined. Piperlonguminine increased mRNA levels of adiponectin, glu...

The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang province, China, showed an inhibitory effect on aldose reductase. From the methanolic extract, five new acylated sucroses, mumeoses F-J, were isolated together with 29 known compounds. The chemical structures of the new compounds were elucidated on the basis of chemi...

Five new acylated sucroses, mumeoses K-O, and a new acylated flavonol glycoside, mumeflavonoside A, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated acyl...

A methanolic extract and its ethyl acetate-soluble fraction from Sri Lankan curry-leaf, the leaves of Murraya koenigii, inhibited melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. Two new carbazole alkaloids, karapinchamines A and B, were isolated from the ethyl acetate-soluble fraction together with 12 known carbazole alkaloi...

Two novel secoiridoid glycosides with a pyridine ring named hydrangeamines A and B have been isolated from the flowers of Hydrangea macrophylla SERINGE var. thunbergii MAKINO (Saxifragaceae). The absolute stereostructures of the two hydrangeamines were characterized on the basis of chemical and physiochemical analyses, which included the applicatio...

Abstract Ceramides (Cer) and glucosylceramides (GlcCer) play an important role in moisturizing the epidermis. Dietary GlcCer has been reported to improve transepidermal water loss (TEWL). However, the effect of GlcCer on epidermal Cer and GlcCer has not been well established. Therefore, we prepared a GlcCer-rich fraction (GCFr) from rice and evalua...

A multi-component quantification fingerprint based on HPLC coupled with diode-array detector and electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI/MS) technique has been established for the analysis of phenolic compounds in twelve samples originated from five different cultivars of Chrysanthemum morifolium flowers in China. Four caffeo...

Methanolic extracts from the flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) were found to show inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extracts, a new alkaloid, N-methylasimilobine N-oxide, was isolated together with eleven benzylisoquinoline alkaloid...

Aims: Endoplasmic reticulum (ER) stress has been implicated as a cause of various neurodegenerative diseases. We evaluated the protective effects of purple rice (Oryza sativa L.) bran extract (PRE) and its constituents, namely cyanidin, peonidin, and a newly isolated compound 2-hydroxy-5-[(3S)-3-hydroxybutyl]phenyl-β-D-glucoside (HHPG), against tu...

The methanolic extract and its 1-butanol-soluble fraction from the flower buds of Camellia japonica, cultivated in Yunnan Province, China, showed inhibitory effects on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. From the 1-butanol-soluble fraction, a new 28-nor-oleanane-type and three new oleanane-type triterpene saponins, sanc...