Kazuo Masuda

Bacopaside I and II: two pseudojujubogenin glycosides from Bacopa monniera.

Two saponins, designated as bacopaside I and II, have been isolated from Bacopa monniera Wettst. and their structures have been elucidated as 3-O-alpha-L-arabinofuranosyl-(1-->2)-[6-O-sulphonyl-beta-D-glucopyranosyl-(1-->3)]-alpha-L-arabinopyranosyl pseudojujubogenin (1) and 3-O-alpha-L-arabinofuranosyl-(1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl pseudojujubogenin (2) mainly on the basis of 2D NMR and other spectral analyses.

Identification of medicinal Dendrobium species by phylogenetic analyses using matK and rbcL sequences.

Species identification of five Dendrobium plants was conducted using phylogenetic analysis and the validity of the method was verified. Some Dendrobium plants (Orchidaceae) have been used as herbal medicines but the difficulty in identifying their botanical origin by traditional methods prevented their full modern utilization. Based on the emerging field of molecular systematics as a powerful classification tool, a phylogenetic analysis was conducted using sequences of two plastid genes, the maturase-coding gene (matK) and the large subunit of ribulose 1,5-bisphosphate carboxylase-coding gene (rbcL), as DNA barcodes for species identification of Dendrobium plants. We investigated five medicinal Dendrobium species, Dendrobium fimbriatum, D. moniliforme, D. nobile, D. pulchellum, and D. tosaense. The phylogenetic trees constructed from matK data successfully distinguished each species from each other. On the other hand, rbcL, as a single-locus barcode, offered less species discriminating power than matK, possibly due to its being present with little variation. When results using matK sequences of D. officinale that was deposited in the DNA database were combined, D. officinale and D. tosaense showed a close genetic relationship, which brought us closer to resolving the question of their taxonomic identity. Identification of the plant source as well as the uniformity of the chemical components is critical for the quality control of herbal medicines and it is important that the processed materials be validated. The methods presented here could be applied to the analysis of processed Dendrobium plants and be a promising tool for the identification of botanical origins of crude drugs.

Carbazole alkaloids from roots of Glycosmis arborea

Abstract A new carbazole alkaloid, designated as glycoborinine, was isolated from the roots of Glycosmis arborea , along with two other known carbazole alkaloids, viz. glycozoline and glycozolidine, and two known quinoline alkaloids, viz. skimianine and 3- (3′,3′-dimethylallyl)-4,8-dimethoxy- N -methylquinolin-2-one. Its structure was elucidated mainly on the basis of its 2D NMR spectral analyses.

A novel multifunctional triterpene synthase from Arabidopsis thaliana

The Arabidopsis thaliana genome sequencing project has identified several triterpene synthase homologues. One cDNA of these clones, YUP8H12R.43, was obtained and functionally expressed in yeast. At least nine triterpenes have been identified as its products based on NMR and LCMS analysis. The products include extensively migrated triterpenes, multiflorenol and bauerenol. Several chimeric clones were constructed between YUP8H12R.43 and A. thaliana lupeol synthase LUP1, to reveal that a C-terminal half and a part of N-terminus is important for such product multiplicity. The presence of such multifunctional triterpene synthase in plants is noteworthy from both a mechanistic and a physiological point of view.

Fern constituents: Polypodatetraenes, novel bicyclic triterpenoids, isolated from polypodiaceous and aspidiaceous plants

Abstract Two new oily triterpenoid hydrocarbons having a novel bicyclic carbon skeleton, named α- and γ-polypodatetraenes ( 1 and 2 , respectively), were isolated from the fresh leaves of Polypodium fauriei and Lemmaphyllum microphyllum ( 1 ), and Polystichum ovatopaleaceum and P. polyblephalum ( 2 ). Their structures were established to be polypoda-8(26), 13,17,21-tetraene ( 1 ) and polypoda-7,13,17,21-tetraene ( 2 ) by physico-chemical methods.

Screening of Nepalese crude drugs traditionally used to treat hyperpigmentation: in vitro tyrosinase inhibition.

South‐East Asian population is daily exposed to strong sunlight. As a result, the majority of population will have darker, ethnic skin. Moreover, many people suffer from dark spots, hyperpigmentation, which is considered to be a skin disorder and causes psychological disturbance. To treat dark spots, most of the population will still rely on traditionally used crude drugs, knowledge about which is transferred from generation to generation. Fifty‐two crude drugs were selected based on the survey performed among local healers and beauticians of different ethnic origin. These crude drugs were screened for mushroom tyrosinase inhibitory activity, as tyrosinase inhibitors are becoming increasingly important as cosmetic and medicinal products, primarily to control hyperpigmentation. Among the tested crude drugs, methanolic extracts of Glycyrrhiza glabra, Morus alba, Syzygium aromaticum, Citrus aurantifolia, Cypreae moneta, Punica granatum and Citrus aurantium, at the final concentration of 50 μg mL−1, showed mushroom tyrosinase inhibitory activity of 78.9%, 71.0%, 69.4%, 59.0%, 56.0%, 53.4 and 51.9%, respectively, with 91.4% inhibitory activity of kojic acid taken as positive control. To our knowledge, this is the first report that extracts of Cypreae moneta shell and Syzygium aromaticum flowering bud have tyrosinase inhibitory activity. These potent extracts were further evaluated at different concentration. The final concentration of the extracts in reaction mixtures was 50, 25 and 5 μg mL−1 for the initial concentration of 1000, 500 and 100 μg mL−1, respectively. They showed concentration‐dependant inhibition of mushroom tyrosinase. Those extracts expressing relatively weak tyrosinase inhibitory activity may act through different inhibition pathway which is not based on tyrosinase activity. Further evaluation of the most potent tyrosinase inhibitors in in vivo conditions would be recommended.

The “Prunus mume Sieb. et Zucc” (Ume) is a Rich Natural Source of Novel Anti-Cancer Substance

The apricot variety in Japan is “Prunus mume Sieb. et Zucc” (Ume). The Japanese have been growing Ume tree for more than 2000 years because of its health enhancing effects, and through cultivation, they have improved the Ume tree to produce healthier fruits. The purpose of this study was to investigate presence of anti-cancer substances in Ume. One kg Ume was squeezed to separate the soft fruit from the seed capsules. The soft Ume fraction was boiled at 90°C to 100°C to obtain 20 g of semi-solid Ume (misatol). The condensed fruit was dissolved in a water-diethylether. The fraction in diethylether was dried and further fractionated for experiments. The anti-cancer effects of the Ume were investigated on 2 established cancer cells—the Kato-III stomach cancer and the HL-60 promyelocytic leukaemia cell lines. Kato-III and HL-60 cells were grown in RPMI-1640 medium containing 10% foetal calf serum. The Ume extract in dimethyl sulphoxide was added to the cancer cell cultures at 1–10 μL/mL test (1 μL contained 20 μg extract). Without Ume, the cancer cells grew and formed colonies. When the Ume extract was added, cancer cells were dose dependently eliminated and at < 5 μL/mL, no cancer cell survived. Similarly, the condensed Ume showed strong anti-tumour effects on human pancreatic cancer and dog fibrosarcoma. The Ume preparation showed no toxic effect on normal human blood cells. In conclusion, this is the first study showing unequivocally presence of an anti-cancer agent in Ume fruit with both suppressive effect on the growth of cancer cells and lethal action on the already formed cancer cell colonies. As an abundant source of natural anti-cancer substance, Ume should have therapeutic benefit in tumour-bearing patients. Further, regular intake of Ume juice should suppress cancer initiation in healthy individuals.

Taraxastane glycosides from Eclipta alba

Abstract From the dried whole plants of Eclipta alba (Ecliptae Herba, Chinese name Mo Han Lian) purchased in China, four new taraxastane triterpene glycosides, named eclalbasaponins VII–X were isolated, along with eclalbasaponins I–VI. The structures of eclalbasaponins VII–X were characterized as 3β,20β,16β- and 3β,20β,28-trihydroxytaraxastane glycosides, and their sulphated saponins on the basis of spectral data.

Squalene cyclase and oxidosqualene cyclase from a fern

Ferns are the most primitive vascular plants. The phytosterols of ferns are the same as those of higher plants, but they produce characteristic triterpenes. The most distinct feature is the lack of oxygen functionality at C‐3, suggesting that the triterpenes of ferns may be biosynthesized by direct cyclization of squalene. To obtain some insights into the molecular bases for the biosynthesis of triterpenes in ferns, we cloned ACX, an oxidosqualene cyclase homologue, encoding a cycloartenol synthase (CAS) and ACH, a squalene cyclase homologue, encoding a 22‐hydroxyhopane synthase from Adiantum capillus‐veneris. Phylogenetic analysis revealed that ACH is located in the cluster of bacterial SCs, while ACX is in the cluster of higher plant CASs.

Dammarane triterpenoids from rhizomes of Pyrrosia lingua

Hexane extract of fresh rhizomes of Pyrrosia lingua (Thunb.) Farwell. yielded five new dammarane triterpenoids, designated as octanordammarane (1), (18S)-18-hydroxydammar-21-ene (3), (18S)-pyrrosialactone (5), (18S)-pyrrosialactol (7) and 3-deoxyocotillol (8), along with known dammara-18(28),21-diene (2). Structures of 1, 3, 5, 7 and 8 were elucidated by mainly 2D NMR and other spectroscopic analyses and chemical correlations.