Vol 11, Issue 5, 2018 Online - 2455-3891 Print - 0974-2441 A REVIEW ON TABERNAEMONTANA SPP.: MULTIPOTENTIAL MEDICINAL PLANT ANAN ATHIPORNCHAI* Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Burapha University, Bangsaen, Chonburi 20131 Thailand. Email: anana@buu.ac.th Received: 01 March 2016, Revised and Accepted: 29 January 2018 ABSTRACT Plants in the genus Tabernaemontana have been using in Thai and Chinese traditional medicine for the treatment several diseases. The great majority constituents of Tabernaemontana species have already been subjected to isolation and identification of monoterpene indole alkaloids present in their several parts. Many of monoterpene indole alkaloids exhibited a wide array of several activities. The biogenesis, classification, and biological activities of these alkaloids which found in Tabernaemontana plants were discussed in this review and its brings the research up-to-date on the bioactive compounds produced by Tabernaemontana species, directly or indirectly related to human health. Keywords: Tabernaemontana plants, Phytochemistry, Biogenesis, Terpene indole alkaloids, Biological activities. INTRODUCTION Several already drugs were discovered from the natural products. Especially, the treatments of infectious diseases and oncology have benefited from numerous drugs which were found in natural product sources. Some of new and interesting natural compounds with biological activities have been published in the past few years. The potent biological activities, no side effects, and economic viability of medicinal properties from natural products have been investigated in the recent scientific developments worldwide. Bioactive compounds from medicinal plants showed pharmacological or toxicological effects in man and animals. The typical bioactive compounds are secondary metabolites including steroids, glycosides, phenolics, tannins, anthocyanins, flavonoids, and alkaloids. The basic structural of alkaloids are nitrogen-containing compounds. The several properties of alkaloids are bitter taste and usually with potent biological activities. Moreover, these secondary metabolites have diverse clinical biological properties [1-3]. Name of the genus Tabernaemontana is the birthplace (Tabermaemontanus) of J. Th. Miiller, a German physician and botanist who was born in Bergzabern and died in Heidelberg in the Pfalz in 1590. The genus of Tabernaemontana belonging to the Apocynaceae family and composing about 100 species distributed throughout the tropical and some subtropical parts of the world. Many of plants in the Tabernaemontana species are used in traditional medicine and for other purposes for the treatment of sore throat, hypertension, and abdominal pain [4-6]. Plants of Tabernaemontana genus are a prolific source of the monoterpene indole alkaloids and they have been shown to produce many skeletal types such as secotabersonine alkaloids, bis- vobtusine-type alkaloids, and bis-vobasinyl-ibogan indole alkaloids [7- 9]. These alkaloids are a diverse class of natural products, comprising over 2000 members and possess a range of chemical structures and a wealth of biological activities such as anticancer, antimalarial, and anti- arrhythmic agents [10]. Therefore, the biogenesis, classification, and biological activities of the indole alkaloids found in Tabernaemontana species were discussed in this review and its bring the research up- to-date on the bioactive compounds produced by Tabernaemontana species, directly or indirectly related to human health. Classification and biogenesis of monoterpene indole alkaloids Many skeletal types of monoterpene indole alkaloids from Tabernaemontana plants were exhibited a wide array of biological activities. Then, the biosynthetic pathways of some classes of these alkaloids are investigated. All monoterpene indole alkaloids are derived from aromatic amino acid tryptophan and the iridoid terpene secologanin (Scheme 1). Tryptophan converts to tryptamine using tryptophan decarboxylase which is a pyridoxal-dependent enzyme. The specific iridoid precursor was subsequently identified as secologanin. After that, tryptamine was reacted with the secologanin using the enzyme strictosidine synthase catalyzes a stereoselective Pictet-Spengler condensation to yield strictosidine (iso-vincoside) (S stereochemistry at C5, Scheme 1), and this step is utilized in the first committed step of monoterpene indole alkaloid biosynthesis. The Rubiaceae, Nyssaceae, Loganiaceae, and Apocynaceae families of medicinal plants each produce monoterpene indole alkaloids with dramatically diverse structures. The mechanisms and control of the processes by which strictosidine rearranges into these diverse families of products remain one of the most fascinating problems in secondary metabolism [10]. The biosynthesis pathway of strictosidine rearranges also use as a basis for the classification of the monoterpene indole alkaloids occurring in the genus Tabernaemontana. Eleven classes of these alkaloids were reported to the structural characteristics of their skeletons including (1) vincosan, (2) corynanthean, (3) vallesiachotaman, (4) strychnan, (5) aspidospermatan, (6) plumeran, (7) eburnan, (8) ibogan, (9) tacaman, (10) bis-indole alkaloids, and (11) miscellaneous. The classification of the monoterpene indole alkaloids occurring in the genus Tabernaemontana were shown in Table 1 and Scheme 2 [4,10]. Bioactive compounds from the genus Tabernaemontana The plants of genus Tabernaemontana have been used in traditional medicine for the treatment of sore throat, hypertension, and abdominal pain [6]. The chemical constituents from several parts of the Tabernaemontana species were reported as monoterpene indole alkaloid compounds, and these compounds were shown to exhibit a wide array of biological activities including anticancer, antimalarial, and anti-arrhythmic agents [10]. This review brings the research up- to-date on the bioactive compounds produced by Tabernaemontana species, directly, or indirectly related to human health. Tabernaemontana australis (Müell. Arg) Miers Andrade et al. reported the isolation and identification of ten indole alkaloids including coronaridine (1), voacangine (2), voacangine hydroxyindolenine (3), rupicoline (4), ibogamine (5), © 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2018.v11i5.11478 Review Article