13C NMR spectra of pentacyclic triterpenoids--a compilation and some salient features

Chem. Pharm. Bull.(オピニオン)

Complementary and alternative medicines such as tea tree (melaleuca) oil have become increasingly popular in recent decades. This essential oil has been used for almost 100 years in Australia but is now available worldwide both as neat oil and as an active component in an array of products. The primary uses of tea tree oil have historically capitalized on the antiseptic and anti-inflammatory actions of the oil. This review summarizes recent developments in our understanding of the antimicrobial and anti-inflammatory activities of the oil and its components, as well as clinical efficacy. Specific mechanisms of antimicrobial and anti-inflammatory action are reviewed, and the toxicity of the oil is briefly discussed.

/pdf/melaleuca-alternifolia-tea-tree-oil-a-review-of-3ghwwlak43.pdf

Melaleuca alternifolia (Tea Tree) Oil: a Review of Antimicrobial and Other Medicinal Properties

Saponins, classification and occurrence in the plant kingdom

Molecular activities, biosynthesis and evolution of triterpenoid saponins.

Ursane type triterpene is one of the most widespread triterpene aglycones found in plants, together with oleanane type, and these two types often occur together in the same plant. Pisum sativum is known to produce both types of triterpenes. Homology based PCRs with degenerate primers designed from the conserved sequences found in the known beta-amyrin synthases have resulted in cloning of two triterpene synthase cDNAs from immature seeds of P. sativum. They show high sequence identities to each other (78%) and also to the known beta-amyrin synthases (70-90%). ORFs of the full-length clones named as PSY (2277 bp, codes for 759 amino acids) and PSM (2295 bp, codes for 765 amino acids) were ligated into the yeast expression vector pYES2 under the control of GAL1 promoter. Heterologous expression in yeast revealed PSY to be a P. sativum beta-amyrin synthase. Surprisingly, however, PSM turned out to be a novel mixed amyrin synthase producing both alpha- and beta-amyrin. Several minor triterpenes were also identified as the PSM byproducts. The presence of such multifunctional triterpene synthase would account for the co-occurence of ursane and oleanane type triterpenes in plants.

Molecular cloning and functional expression of triterpene synthases from pea (Pisum sativum): new α-amyrin-producing enzyme is a multifunctional triterpene synthase.

https://www.jstage.jst.go.jp/article/cpb1958/40/7/40_7_1683/_pdf

Mass spectra of pentacyclic triterpenoids

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.

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

A novel multifunctional triterpene synthase from Arabidopsis thaliana

Synopsis

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.

Resume

La population du Sud Est asiatique est exposee journellement a un fort ensoleillement. Il en decoule que la majorite de la population possede une peau ethnique plus foncee. De plus, de nombreuses personnes souffrent de taches brunes, hyperpigmentation consideree comme un desordre cutane qui provoque des troubles psychologiques. Dans le but de traiter les taches brunes, la plupart de la population fait encore appel aux remedes traditionnels dont la connaissance est transmise de generation a generation. Cinquante deux remedes ont ete selectionnes sur la base d’une enquete realisee parmi les guerisseurs locaux et estheticiens de differentes origines ethniques. Puisque les inhibiteurs de tyrosinase deviennent de plus en plus importants en tant que produits cosmetique et medicinaux, en particulier pour controler l’hyperpigmentation, ces remedes ont eteetudies au travers l’activite inhibitrice de la Tyrosinase de champignon. Parmi les remedes testes, des extraits de Glycyrrhiza glabra, Morus alba, Syzygium aromaticum, Citrus aurantifolia, Cypreae moneta, Punica granatum, and Citrus aurantiuma la concentration finale de 50 μg mL−1 ont montre une activite inhibitrice de la tyrosinase de champignons respectivement de 78.9%, 71.0%, 69.4%, 59.0%, 56.0%, 53.4 et 51.9%, alors que l’activite de l’acide kojique prise en tant que controle positif montrait une activite inhibitrice de 91.4%. A notre connaissance, c’est la premiere fois que des extraits de coquille de Cypreae moneta et de bouton floral de Syzygium aromaticum ont montre une activite inhibitrice de la tyrosinase. Ces puissants extraits ont de plus eteevalues a differentes concentrations. La concentration finale de ces extraits dans les melanges reactionnels etait de 50, 25 et 5 μg mL−1 pour une concentration initiale respectivement de 1000, 500 et 100 μg mL−1. Ils ont montre une inhibition de la tyrosinase de champignons dependante de la concentration. Les extraits exprimant une activite inhibitrice de la tyrosinase assez faible peuvent agir au travers un chemin d’inhibition different, non base sur l’activite tyrosinase. Une evaluation complementaire des inhibiteurs de tyrosinase les plus puissants dans des conditions in vivo est conseillee.

Kazuo Masuda

Papers

Molecular cloning and functional expression of triterpene synthases from pea (Pisum sativum): new α-amyrin-producing enzyme is a multifunctional triterpene synthase.

Mass spectra of pentacyclic triterpenoids

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

A novel multifunctional triterpene synthase from Arabidopsis thaliana

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