Flavonoids from the flowers of Adenium obesum (Forssk.) Roem. & Schult., Mandevilla sanderi (Hemsl.) Woodson,and Nerium oleander L. (Apocynaceae)

Twenty-two ornamental flowers from different Adenium obesum, Mandevilla sanderi, and Nerium oleander cultivars/seedlings were analyzed for the presence of anthocyanins, flavonols, and chlorogenic acid using nuclear magnetic resonance (NMR) and mass spectrometry (MS). Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major and minor anthocyanins, respectively, in three A. obesum seedlings that had red and red-purple flowers.Cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the major anthocyanin, whereas cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the minor anthocyanins in 8 M. sanderi cultivars that had red and red-purple flowers. Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major anthocyanins, whereas cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the minor anthocyanin in 8 N. oleander cultivars with red and red-purple flowers. Low levels of anthocyanins were detected in the N. oleander and M. sanderi cultivars that had white flowers, and there were no anthocyanins detected in the N. oleander cultivars with yellow flowers. Chlorogenic acid and four flavonols, quercetin 3-O-[6-O-(rhamnosyl)-galactoside], quercetin 3-O-[6-O-(rhamnosyl)-glucoside], kaempferol 3-O-(galactoside), and kaempferol 3-O-[6-O-(rhamnosyl)-galactoside], were identified in the flowers from all 22 cultivars/seedlings investigated.     

Chemical constituents from Lagopsis supina (Steph.) Ik.-Gal. ex Knorr

Phytochemical investigation of the whole plants of Lagopsis supina (Steph.) Ik.-Gal. ex Knorr. led to the isolation of 18 compounds (1–18), including ten phenylethanoid glycosides (1–10), one phenylmethanoid glycoside (11), four megastigmane glycosides (12–15), and three monoterpenoid glycosides (16–18). Lagopsides A (1) and B (2) were identified as new phenylethanoid glycosides. This is the first report of compounds 7, 11, 12, 15, and 16 from the Labiatae family, while compounds 4–6, 8–10, 13–14, and 17–18 were isolated from the genus Lagopsis for the first time. The chemotaxonomic significance of these isolated compounds was summarized.     

Secondary metabolites from Centaurea ensiformis P.H. Davis

Centaurea ensiformis P.H. Davis was evaluated for its secondary metabolites. 20 different compounds have been isolated and identified; four phenolic compounds, one aminoacid, two acetophenone glycosides, three phenylpropanoide glycosides, one coumarin glucoside, four flavon glycosides, two neolignan glycosides, two megastigmane glycosides and schikimic acid methyl ester.     

Iridoid glycosides from the stems of Pithecoctenium crucigerum (Bignoniaceae)

Sixteen crude extracts from six Panamanian plants of the family Bignoniaceae were submitted to rapid TLC tests against DPPH and acetylcholinesterase. Pithecoctenium crucigerum (L.) A.H. Gentry, which showed interesting activity against DPPH, has been studied. The chemical investigation of the methanol extract from the stems afforded the iridoid glycoside theviridoside and three derivatives (6'-O-cyclopropanoyltheviridoside, 10-O-hydroxybenzoyltheviridoside and 10-O-vanilloyltheviridoside), along with five known phenylethanoid glycosides (verbascoside, isoverbascoside, forsythoside B, jionoside D and leucosceptoside B). These last compounds were all active against DPPH. The structures were determined by means of spectrometric and chemical methods, including 1D and 2D NMR experiments and MS analysis.     

Chemical constituents of Odontites serotina (Lam.) Dumort. (Orobanchaceae)

The study of the whole plants of Odontites serotina (Lam.) Dumort. has led to the isolation of one nucleoside compound (2), three iridoids (1, 3, and 4), two phenylethanolic glycosides (6 and 8), four phenolic acids (5, 10, 12, and 15), and nine flavonoids (7, 9, 11, 13, 14, and 16–19). The structures of the compounds were identified by nuclear magnetic resonance (NMR) and high-resolution mass spectrometer. To the best of our knowledge, this is the first study to describe the isolation and identification of compounds 2–3, 6–8, 10, 12, 14–16, and 19 in O. serotina. The chemotaxonomic significance of these compounds was discussed.     

Systematics, ecology and phylogeographic significance of Olea europaea L. ssp. maroccana (Greuter & Burdet) P. Vargas et al., a relictual olive tree in south-west Morocco

Within the genus Olea , the olive ( Olea europaea L.) possesses the largest geographic distribution, and several subspecies have been described. South-west Morocco harbours an endemic olive, O. europaea ssp. maroccana (Greuter & Burdet) P. Vargas et al. , located in the western part of the High Atlas (mainly on the southern slope of the Ida-ou-Tanane massif) and in the western Anti Atlas. The existence and the taxonomic position of this tree have long remained uncertain, but the combination of several morphological traits is unique. Nuclear and cytoplasmic DNA polymorphism also demonstrate that this tree is a well-differentiated and relictual taxon, probably originating from an ancestral unit within tropical Africa. Our findings refute the opinions of several authors who consider ssp. maroccana to be intermediate between the cultivated olive ( O. europaea ssp. europaea ) and the Saharan olive ( O. europaea ssp. laperrinei (Batt. & Trab.) Cif.). According to cpDNA and mtDNA analysis, the Moroccan olive and the Canarian olive ( O. europaea ssp. guanchica P. Vargas et al. ) are related and belong to the same sub-taxon. This biogeographical affinity is strongly supported by other recent phylogenetic studies. The long-term viability of ssp. maroccana is threatened by several factors: (1) limited distribution and reduced numbers of individuals within isolated populations, (2) fragmentation processes related to human and livestock pressures, and (3) putative gene flow between this taxon and the cultivated olive. In order to ensure the long-term survival of this endemic olive, a specific program of conservation should be implemented in the near future.     

Secondary metabolites from Argania spinosa (L.) Skeels

Argania spinosa (L.) Skeels is a tree that plays a crucial role in the rural and urban economy of Morocco. Not only is the tree used in traditional medicine but its fruits contain almonds used to prepare an edible oil, its leaves are utilized to feed cattle, and its wood is used as fuel. In addition the tree is particularly well-adapted to arid lands and could hence be used to limit the desert progression that is threatening subtropical African countries. Consequently a program aimed at a better understanding of all the aspects and uses of the argan tree is currently being carried out in Morocco. This review summarizes the results gathered so far on the phytochemical and pharmacological activity of A. spinosa. This revised version was published online in June 2006 with corrections to the Cover Date.     

A new flavone glycoside from the leaves of Agastache rugosa (Fisch. & C.A.Mey.) Kuntze

Agastache rugosa (Fisch. & C.A.Mey.) Kuntze has been widely used as a food spice and a remedy for colds in Korea, China and Japan. In this study, one new flavone glycoside (1) along with six flavonoids (2–7), nine phenyl glycosides (8–16) and three megastigmane glycosides (17–19) were isolated from the leaves of A. rugosa. By extensive spectroscopic methods including 1D and 2D NMR, and MS data, the structure of the new compound (1) was elucidated as acacetin 7-O-β-(6″-(E)-crotonylglucopyranoside). From present investigation, compound 1 and 7–19 were isolated for the first time from the genus Agastache and 1, 16, 18 and 19 in the Lamiaceae family.     

Glandular trichomes and essential oil composition of endemic Sideritis italica (Mill.) Greuter et Burdet from central Italy

Sideritis italica (Mill.) Greuter et Burdet belongs to the Lamiaceae family and is endemic to Italy. The glandular trichomes (morphology, distribution, histochemistry, and ultrastructure) of the plant were studied for the first time, along with the chemical composition of the essential oils. Abundant non-glandular hairs and peltate (type A) and capitate (types B, C(1), and C(x)) glandular trichomes were observed both on the vegetative and reproductive organs. The histochemical procedures and the ultrastructural investigation enabled specific location of the main site of essential oil production mainly in type-A peltate hairs. Particular emphasis is given to the release mechanism of the secreted material in all of the types of glands, and the potential taxonomic value of the indumentum in the Lamiaceae family is briefly discussed. Essential oils were hydrodistilled from flowering aerial parts of S. italica, and 136 compounds (112 in flowerheads, 79 in vegetative parts) were identified. The quantitative prevalence of diterpenoids (43.4% in flowerheads and 22.3% in vegetative parts) was the most significant characteristic of the essential oil of S. italica that could be classified as a diterpene-rich essential oil according to the classification of Kirimer.     

Synthetic analogues of durantoside I from Citharexylum spinosum L. and their cytotoxic activity

New iridoid glycoside derivatives from durantoside I, the latter from the dried flowers and leaves of Citharexylum spinosum, were synthesized by variously modifying a sugar moiety by silylation or acetylation and/or removal of cinnamate group at C-7 position and subsequent screening for comparative cytotoxicity against several cancer cell lines. Addition of alkylsilane to durantoside I and removal of cinnamate group were most effective in improving cytotoxicity.     

A new sesquiterpenoid from Sclerorhachis platyrachis (Boiss.) Podlech ex Rech.f

A new eudesmane-type sesquiterpenoid together with two known flavonoids were isolated from the chloroform extract of the aerial part of Sclerorhachis platyrachis. The structure of the new compound was deduced from its comprehensive spectroscopic analysis including IR, EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC and was shown to be 4R^*-hydroxy-6S^*-tigloyloxyeudesma-7S^*-11 (13)-en-12-oic acid (1). Finally, the structure of the new compound was unambiguously confirmed by single-crystal X-ray analysis. The structure of known compounds 2 and 3 were identified by comparison of their spectral data with those reported in the literature.     

Secondary metabolites from Spiranthes sinensis (Orchidaceae)

One new flavonol glycoside (1) and nine known compounds (2–10) were obtained from the n-BuOH soluble fraction of the whole plants of Spiranthes sinensis. The structure of compound 1 was elucidated based on the combination of spectroscopic (¹H-NMR, ¹³C-NMR, HSQC, and HMBC as well as HR-ESI-MS) and chemical methods. The occurrences of eight compounds (2-9) in this genus were firstly reported while five of them (2–6) were obtained from Orchidaceae for the first time. Furthermore, the chemotaxonomic significance of these compounds was discussed.     

Benzofuranylethanoid and phenylethanoid esters from Pteropyrum scoparium (Jaub. & Spach)

Pteropyrum scoparium Jaub. & Spach (Polygonaceae) is a naturally growing shrub used as food crop in Oman. The chemical investigation of the ethyl acetate extracts of the leaf afforded phenylethanoid, benzofuranylethanoid and ethyl esters of caproic and lauric acids (1–3), proanthocyanidin trimer epicatechin-3-O-gallate-(4 → 8)-epicatechin-3-O-gallate-(4 → 8)-epicatechin-3-O-gallate (4) and epicatechin-3-O-gallate (5). Compounds 1 and 3 are new and isolated for the first time from P. scoparium. The structures of compounds were assigned based on 1D and 2D NMR spectroscopy and ESI–MS analysis. Compounds 1 and 3 were tested for free radical scavenging anti-oxidant properties and found to inhibit 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) by 1.7% and 41.0%, respectively compared to 71% and 78% for gallic acid and butylated hydroxyanisole used as control.     

Triterpenoid saponins from Piptadeniastrum africanum (Hook. f.) Brenan

One new triterpenoid saponin, named piptadeniaoside (1), along with two known saponins (2–3) have been isolated from the stem bark of Piptadeniastrum africanum. After previous isolation of flavone derivatives from this plant, new phytochemical investigations were performed for its saponin content. Their structures were established by direct interpretation of their spectral data, mainly HRESIMS, 1D NMR (¹H, ¹³C NMR, DEPT) and 2D NMR (COSY, NOESY, HSQC and HMBC), and by comparison with the literature data.     

Phenolics from Tanacetum sinaicum (Fresen.) Delile ex Bremer & Humphries (Asteraceae)

The phytochemical investigation on Tanacetum sinaicum (Fresen.) Delile ex Bremer & Humphries led to the isolation of eight flavonoid aglycones (apigenin 1, acacetin 2, luteolin 3, chrysoeriol 4, cirsilineol 5, jaceidin 6, chrysosplenetin 7 and vitexicarpin; casticin 8), four flavonoid glycosides (apigenin 7-O-β-glucopyranoside 9, apigenin 7-O-β-glucuronide 10, luteolin 7-O-β-glucopyranoside 11 and luteolin 7-O-β-glucuronide 12) and three phenolics (4-hydroxy-3-methoxy benzoic acid 13, 3,4-dimethoxy benzoic acid 14 and 4-hydroxy acetophenone 15). Their structures were determined by chemical and spectroscopic analysis. Among them, compounds 1–3, 9, 11, 13 and 14 were reported for the first time from T. sinaicum. The chemotaxonomic significance of the isolated flavonoids was also summarized.