Stoloniferins VIII-XII, resin glycosides, from Ipomoea stolonifera

A Review on Pharmacological and Phytochemical studies towards convolvulaceae species Rivea and Ipomea

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The plants of Rivea and Ipomea are Convolvulaceae species which were identified by their funnel like flowers and radial shaped corolla.The stems of these plants are slender and creeper type.The plant of ipomea contain simple leaves.Whereas the leaves of Rivea are velvety in texture and have a shiny appearance.The fruits are like capsule, berry or nut containing only two seeds per one locule.Mostly Convolvulaceae species are eaten as a fresh leafy vegetable,which has been used traditionally for curing many ailments such as purgative,skin disease and as a blood purifier for arthritis, piles and urinary disorder.Both these plants explain the therapeutic benefits such as curing diabetes, skininfections ,snakebite, ulcer and also posses antimutagenic activities and act as a immune booster and help in the relief of respiratory congestion.On highlighting their phytochemical aspects both the plants shows the presence of flavanoids, terpenoids, poly phenols, carbohydrates, alkaloids, sterols and glycosides.As these plants is creepers,tribal people use their leafy part for their neutraceutical value.

Batatins VIII-XI, glycolipid ester-type dimers from Ipomoea batatas

Sweet potato (Ipomoea batatas) is native to the tropics of Central and South America, where many varieties have been consumed for more that 5000 years. In developing countries, this crop is a recognized effective food for fighting malnutrition. Purification of the minor lipophilic glicolipids found in the n-hexane-soluble resin glycosides from the white-skinned variety was performed by preparative-scale recycling HPLC. Application of column overload, peak shaving, heart cutting, and recycling techniques permitted the purification of four new oligosaccharide ester-type dimer derivatives of jalapinolic acid, batatins VIII-XI (1-4). The structural characterization of these complex lipo-oligosaccharides was performed through NMR spectroscopy and MS, indicating that batatins VIII-XI (1-4) possess an oligomeric structure consisting of two pentasaccharide units of the known simonic acid B.

Resin glycosides from the yellow-skinned variety of sweet potato (Ipomoea batatas)

Native to tropical America, Ipomoea batatas has been cultivated for over 5000 years in Mexico. The yellow-skinned tuber crop variety, with an orange flesh, has a higher nutritional value than potato. Raw sweet potato can cause a purge due to its resin glycoside content. Purification of the chloroform-soluble resin glycosides from the roots of this variety was accomplished by preparative-scale HPLC, which allowed for the collection of six oligosaccharides, batatin VII (1) and batatinosides VII-IX (2-4), all of novel structure, together with the known resin glycosides pescaprein I and batatinoside IV. High-field NMR spectroscopy and FAB mass spectrometry were used to characterize each structure, identifying operculinic acid A for compounds 2 and 4, and simonic acid B for 3, as their pentasaccharide glycosidic cores. Batatin VII (1) represents a dimer of the know batatinoside IV, consisting of two units of simonic acid B.

A New Resin Glycoside from Ipomoea Maxima

A new resin glycoside (1) was isolated from the aerial part of Ipomoea maxima, together with three known compounds, pescaprein XX (2), stoloniferin X (3), and stoloniferin IX (4). The structure of 1 was elucidated on the basis of 1D NMR spectroscopy, a fragmentation study by APCIMS, and HRESIMS analysis.

Batatins III-VI, glycolipid ester-type dimers from Ipomoea batatas

Batatins III-VI (1-4), glycolipid ester-type dimers, were isolated from the tuberous roots of sweet potato (Ipomoea batatas) using recycle high performance liquid chromatography. Their structures were characterized by means of several high-resolution NMR and mass spectrometry techniques. These compounds are the first examples of ester-type dimers which consist of two units of the heterotetrasaccharide operculinic acid C. Each unit was esterified by a different amount and type of acid residues: (2S)-methylbutanoic, cinnamic, decanoic (capric) and dodecanoic (lauric) acids. Batatins III-VI (1-4) are an example of the presence of a large number of resin glycoside congeners in each morning glory species caused by partial acylation of their constitutive saccharide cores.

Pentasaccharide resin glycosides from Ipomoea pes-caprae

Pescapreins XXI-XXX (1-10), pentasaccharide resin glycosides, together with the known pescapreins I-IV and stoloniferin III were isolated from the aerial parts of Ipomoea pes-caprae (beach morning-glory). The pescapreins are macrolactones of simonic acid B, partially esterified with different fatty acids. The lactonization site of the aglycone, jalapinolic acid, was located at C-2 or C-3 of the second saccharide moiety. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-10 were evaluated for their potential to modulate multidrug resistance in the human breast cancer cell line MCF-7/ADR. The combined use of these new compounds at a concentration of 5 μg/mL increased the cytotoxicity of doxorubicin by 1.5-3.7-fold.

Macrocyclic substructure of tricolorin A – The first crystal structure of a resin glycoside

The structure of a tricolorin A derivative (11S)-11-[[4,6-O-benzylidene-β-D-glucopyranosyl-(1 → 2)-3,4-O-isopropylidene-β-D-fucopyranosyl]oxy]hexadecanoic acid 3gluc-lactone 2, a member of the resin glycosides, has been determined. This crystal structure is the first example for this class of natural products. At 100 K the lattice parameters in monoclinic space group P21 are: a = 22.502 (5)Å, b = 17.339( 4)Å, c= 25.011( 5)Å, β= 92.49(3)°, V = 9749(3)Å3 , Z = 10. M = 705.67, ρ= 1.202 Mg m -3 , μ = 0.087 mm-1 , F (000)= 3824. The five crystallographically independent molecules show upon superpositioning the expected preservation of the glycosidic link geometry, however the alkyl part of the macrocyclic ring expresses a larger degree of freedom while conserving gauche and anti conformations in six of nine torsion angles.

Batatinosides II-VI, acylated lipooligosaccharides from the resin glycosides of sweet potato

Sweet potato ( Ipomoea batatas) belongs to the Convolvulaceae (morning glory family) and is native to Mexico and Central America. Its edible tuberous roots have been much appreciated since pre-Hispanic times in Mesoamerica and now play an important role as a basic diet staple and a medicinal plant worldwide. The hexane-soluble extract from roots, through preparative-scale recycling HPLC, yielded five new lipophilic oligosaccharides of jalapinolic acid, batatinosides II-VI ( 1- 5), as well as the known pescapreins I ( 6) and VII ( 7) and murucoidin I ( 8), which are part of the purgative resin glycoside mixture. NMR spectroscopy and FAB mass spectrometry were used to characterize their structures. Compounds 1 and 2 are tetraglycosidic lactones of operculinic acid C. The pentasaccharide structures for compounds 3 and 4 were confirmed to be macrolactones of simonic acid B, and that characterized for 5 was derived from operculinic acid A. The lactonization site of the aglycone was placed at C-3 of the second saccharide unit in all compounds except 4, where it was placed at C-2. All compounds contain an esterifying residue that is composed of a long-chain fatty acid, n-decanoic acid (capric) or n-dodecanoic acid (lauric). In compound 3, an additional short-chain fatty acid, (2 S)-methylbutyric acid, was also identified.

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A-C (1-3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC(50)'s 4.1 and 9.7 microg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 microg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC(50)'s 2.0 and 5.8 microg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC(50) values of 4.2, 16.6 and 22.4 microg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 microg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).

Batatins I and II, ester-type dimers of acylated pentasaccharides from the resin glycosides of sweet potato

Batatins I (1) and II (2), two ester-type dimers of acylated pentasaccharides, have been isolated by recycling HPLC from the hexane-soluble extract of sweet potato (Ipomoea batatas var. batatas). The structures were elucidated by a combination of high-resolution NMR spectroscopy and mass spectrometry. Complete analysis and unambiguous assignments of the 1H and 13C NMR spectra of 1 and 2 were achieved by 2D shift correlation measurements. The glycosidic acid forming each branched pentasaccharide monomeric unit was confirmed as simonic acid B. Three different fatty acids esterify this core at the same positions in both batatins: C-2 on the second rhamnose unit and C-4 and C-2 (or C-3) on the third rhamnose moiety. The acylating residues were identified as (+)-(2S)-methylbutanoic, dodecanoic (lauric), and cinnamic acids. The site of lactonization by the aglycon in unit A was placed at C-3 of the second saccharide. The position for the ester linkage for monomeric unit B on the macrocylic unit A was identified as C-3 of the terminal rhamnose' ''. Through spectroscopic simulation of these complex oligosaccharides, the chemical shifts and coupling constants were deduced for the overlapped proton resonances with a non-first-order resolution. The experimental NMR spectroscopic values registered for batatinoside I (3), a new polyacylated macroyclic pentasaccharide also isolated from this plant, were used as the starting point for spectral simulation of 1 and 2. Both polymers 1 and 2 represent dimers of compound 3.

Crypthophilic acids A, B, and C: resin glycosides from aerial parts of Scrophularia crypthophila

The water-soluble part of the methanolic extract from the aerial parts of Scrophularia crypthophila, through chromatographic methods, yielded three new resin glycosides, crypthophilic acids A - C (1-3). Compounds 1-3 are tetraglycosides of (+)-3S,12S-dihydroxypalmitic acid. The structures of these and 10 known compounds were elucidated by spectroscopic and chemical means. All natural resin glycosides known so far have been obtained from Convolvulaceae plants; this is the first report of such glycosides from another, taxonomically unrelated family (Scrophulariaceae).

Astonishing diversity of natural surfactants: 1. Glycosides of fatty acids and alcohols

Alkyl and fatty acid glycosides have become of great commercial interest in general and specifically for the pharmaceutical, cosmetic, and food industries. Natural surfactants are good sources for future chemical preparation of these glycosides. This review article shows an astonishing diversity of natural surfactants that could be used in laboratories and industry. More than 250 natural surfactants, including their chemical structures and biological activities, are described in this review article.

Characterization of lipophilic pentasaccharides from beach morning glory (Ipomoea pes-caprae)

The hexane-soluble extract from the aerial parts of the herbal drug Ipomoea pes-caprae (beach morning-glory), through preparative-scale recycling HPLC, yielded six lipophilic glycosides, namely, five new pentasaccharides of jalapinolic acid, pescaproside A (1) and pescapreins I-IV (2-5), as well as the known stoloniferin III (6). Saponification of the crude resin glycoside mixture yielded simonic acid B (7) as the glycosidic acid component, whereas the esterifying residues of the natural oligosaccharides comprised five fatty acids: 2-methylpropanoic, (2S)-methylbutyric, n-hexanoic, n-decanoic, and n-dodecanoic acids. Pescaproside A (1), an acylated glycosidic acid methyl ester, is related structurally to the product obtained from the macrolactone hydrolysis of pescapreins I-IV (2-5). All the isolated compounds (1-6), characterized through high-field NMR spectroscopy, were found to be weakly cytotoxic to a small panel of cancer cell lines.

Preparation and diastereomeric separation of an (S)- and (R)-1-(methoxycarbonyl)tridec-10-yl glucoside derivative, a precursor for a monosaccharide constituent of resin glycosides

The 6-O-mesyl derivative of phenyl 1-thio-beta-D-glucopyranoside was prepared from D-glucose as a synthetic equivalent of a 6-deoxy-hexosyl donor. Racemic methyl 11-hydroxytetradecanoate (methyl convolvulinolate) was synthesized by Grignard reaction of propylmagnesium bromide with 10-undecenal followed by hydroboration. Both intermediates were coupled by NIS-TfOH-promoted glycosidation to give a mixture of two diasteromeric glucopyranosides, which were separated on a preparative scale by medium pressure chromatography. One of the products was identified as having the natural (S)-configuration by comparison of its 1H NMR spectrum with an authentic sample prepared from the corresponding chiral hydroxyfatty acid.