Secondary Metabolites from Rubiaceae Species

Revista Brasileira De Farmacognosia-brazilian Journal of Pharmacognosy, 2008

RESUMO: "Alcalóides indólicos monoterpênicos de Chimarrhis turbinata DC. Prodr.: uma contribuição para os estudos de quimiotaxonomia da família Rubiaceae". A utilização de parâmetros apenas morfológicos para posicionar taxonomicamente diversas espécies em subfamílias e tribos na família Rubiaceae é bastante problemática devido à falta de informações sobre a distribuição geográfi ca e de características morfoanatômicas nos níveis hierárquicos mais baixos, como por exemplo, o gênero Chimarrhis. O perfi l micromolecular de diferentes espécies pode auxiliar na delimitação de tribos indicando tendências fi logenéticas mais completas entre as tribos das sub-famílias, já que os metabólitos secundários são expressões de adaptação, regulação e evolução de um determinado táxon. Nesse contexto, os alcalóides indólicos monoterpênicos isolados de Chimarrhis turbinata foram bastante úteis para embasar a classifi cação taxonômica feita por Robbrecht, em que posiciona Chimarrhis como um gênero da tribo Condamineae e subfamília Cinchonoideae.

Biochemical Systematics and Ecology, 2003

Biochemical Systematics and Ecology, 2004

Leaves of 15 Brazilian species of Psychotria, three of Rudgea and Palicourea rigida, were analyzed for their alkaloid and iridoid content. Alkaloids were found in three of Rudgea and 14 species of Psychotria, and iridoids were found in Psychotria leiocarpa, which produces asperuloside and deacetylasperuloside. Palicourea rigida yielded no alkaloids but loganin was isolated. The results illustrate the significance of the alkaloids in the chemotaxonomy of some taxa of Psychotrieae. The phytochemical data indicate that the American species of Psychotria with Palicourea could be joined to form the genus Heteropsychotria.

Chemistry & biodiversity, 2004

Pharmaceutical Biology, 2001

In an effort to study plants of the Rubiaceae from Panama, 299 herbarium samples, representing 133 species, were subjected to alkaloid screening. From this total, 234 samples (78%) afforded a positive test for alkaloids, and 99 samples (33%) gave a positive reaction for indole alkaloids; 109 species (82%) contain alkaloids and 58 (44%) produce indole alkaloids. This is the first time that 102 (94%) and 52 (90%) species are reported as alkaloid and indole alkaloid bearing, respectively. The results of 10 out of 15 species, that is 67%, corroborate earlier studies. The richest indole alkaloid species were: Hamelia patens,

Biochemical Systematics and Ecology, 2001

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ChemInform, 2005

The Uncaria genus is an important source of medicinal natural products, particularly alkaloids and triterpenes. The collected information is an attempt to cover the more recent developments in the ethnobotany, pharmacology and phytochemistry of this genus. During the past 20 years, alkaloids, terpenes, quinovic acid glycosides, flavonoids and coumarins have been isolated from Uncaria. Fifty-three novel structures are reported in this review. The species in which the largest number of compounds has been identified is the Peruvian Uncaria tomentosa or ÔcatÕs claw.Õ Pharmacological studies are described according to cytotoxicity, anti-inflammatory, antiviral, immunostimulation, antioxidant, CNS-related response, vascular, hypotensive, mutagenicity and antibacterial properties. The potential for development of leads from Uncaria continues to grow, particularly in the area of immunomodulatory, anti-inflammatory and vascular-related conditions. The information summarized here is intended to serve as a reference tool to practitioners in the fields of ethnopharmacology and natural products chemistry. (G.B. Hammond). www.elsevier.com/locate/phytochem Phytochemistry 66 (2005) 5-29 PHYTOCHEMISTRY 6 M.E. Heitzman et al. / Phytochemistry 66 (2005) 5-29

Chemical and Pharmaceutical Bulletin, 2007

Iridoids are secondary metabolites of terrestrial and marine flora and fauna and are found in a large number of plant families usually as glycosides. Structurally they are cyclopentano [c] pyran monoterpenoids and biogenetically and chemotaxonomically they provide a structural link between terpenes and alkaloids. 1) A bicyclic H-5/H-9b, b-cis-fused cyclopentanopyran ring system 1a is the most common structural feature of these compounds, however several enantiomeric iridoids also exist in nature. 2,3) Cleavage of cyclopentane ring of iridoids produces seco-iridoids 1b, while cleavage of pyran ring produces iridoid derivatives 1c and hence cyclopentane ring is known as basic skeletal ring of iridoids. In plant kingdom, these are derived from 9-hydroxy nerol by phosphorylation followed by cyclisation, oxidation and glycosidation in several steps. 11) Possibly iridodial 1e or 8-epi-iridodial 1f is the predecessor of iridoids in many plant families. 81,200,201) Iridoids are present in a number of folk medicinal plants used as bitter tonics, sedatives, antipyretics, cough medicines, remedies for wounds, skin disorders and as hypotensives. This fact encouraged to investigate the bioactivities of these phytochemicals. Intensive study of their bioactivity revealed that these compounds exhibit a wide range of bioactivity: cardiovascular, antihepatotoxic, choleretic, hypoglycemic and hypolipidemic, antiinflammatory, antispasmodic, antitumor, antiviral, immunomodulator and purgative activities. 4) Chemotaxonomically they are useful as markers of several genus in various plant families, such as, aucubin 2 of Plantago (Plantaginaceae), 5,6) asperuloside 3 of Galium (Rubiaceae) 7) and aucuboside (aucubin) 2 and harpagide 4 of Scrophularia (Scrophulariaceae). 8) Several review articles on different aspects of iridoids are available elsewhere. The compilation of iridoids are provided in four review articles, namely of El-Naggar and Beal, 9) which covered the new iridoids reported in the literature upto January, 1980; of Boros and Stermitz, 3,10) which covered the new iridoids reported during 1980-1989 and of Hazimi and Alkhathlan, 12) which covered the new iridoids reported during 1990-1993. Among these four the former three review articles presented the iridoids with structures and available

Journal of Natural Products

From the aerial parts of Pentas lanceolata, belonging to the family Rubiaceae, a series of iridoid glucosides was isolated by preparative HPLC. Seven iridoid glucosides were identified. Besides asperuloside and asperulosidic acid, characteristic iridoids for Rubiaceae, five new iridoids were isolated, namely, tudoside (1), 13R-epi-gaertneroside (2), 13R-epiepoxygaertneroside (3), and a mixture of E-uenfoside (4) and Z-uenfoside (5). Further, it was shown that the compound reported as citrifolinin B (6) is in fact the same as tudoside and should be revised. Also, the configuration of the previously reported iridoids gaertneroside and epoxygaertneroside has been elucidated.

Revista Brasileira de Farmacognosia, 2008

RESUMO: "Constituintes químicos de Richardia grandifl ora (Cham. & Schltdl.) Steud. (Rubiaceae)". Dentre as diversas formas de terapia para a prevenção e cura de doenças, as plantas foram, indubitavelmente, as mais amplamente utilizadas desde o início da humanidade. O Brasil tem grande diversidade de plantas com potenciais medicinais, ainda não pesquisados, e que são promissoras fontes de inovações terapêuticas e farmacológicas. A família Rubiaceae, considerada a maior da ordem Gentianales, possui cerca de 637 gêneros e 10.700 espécies. Richardia grandifl ora (Cham. & Schltdl.) Steud., conhecida popularmente como ervanço, poaia ou ipeca-mirim, tem indicações etnofarmacológicas para uso contra hemorróidas e como vermífugo na forma de decocto. Visando a contribuir com o estudo quimiotaxonômico da família Rubiaceae e tendo em vista a ausência de dados na literatura acerca da constituição química de Richardia grandifl ora, esta foi submetida a um estudo fi toquímico para o isolamento de seus constituintes químicos, através dos métodos cromatográfi cos usuais, e posterior identifi cação estrutural dos mesmos, utilizando-se os métodos espectroscópicos de RMN 1 H e 13 C uni e bidimensionais, além de comparações com modelos da literatura. Deste estudo pioneiro com R. grandifl ora foram isolados e identifi cados cinco constituintes: uma mistura dos esteróides-sitosterol e estigmasterol, o ácido o-hidroxibenzóico, o ácido m-metoxi-p-hidroxi-benzóico e a feofi tina A, todos inéditos no gênero Richardia.