Maesa Lanceolata Research Articles

Electronic structure calculations as a tool for investigating acyl migrations in ester saponins.

The possibility of acyl migrations in ester saponins from Maesa lanceolata was investigated by molecular mechanics and electronic structure calculations carried out on the major constituent maesasaponin IV3 (3beta-O-[[alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-[beta-D-galactopyranosyl-(1-->2)]-beta-D-gluco-pyranuronyl]-21beta-angeloyloxy-22alpha-propanoyloxy-13beta,28-oxido-olean-16alpha, 28alpha-diol). It was confirmed that acyl migrations could occur in rings D and E of maesasaponins.

Antiviral, haemolytic and molluscicidal activities of triterpenoid saponins from Maesa lanceolata: establishment of structure-activity relationships.

Ten saponins isolated from the leaves of Maesa lanceolata were tested for their antiviral, haemolytic and molluscicidal activities. The influence of the substitution pattern of these acylated triterpenoid saponins on their biological activities was investigated and structure-activity relationships were established. Maesasaponin VI(2) (3 beta-O-[[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-galactopyranosyl-(1 --> 3)]-[beta-D-galactopyranosyl-(1 --> 2)]-beta-D-glucopyranuronyl]-21 beta,22 alpha-diangeloyloxy-13 beta,28-epoxyolean-16 alpha,28 alpha-diol), the most potent molluscicidal compound (LC(50) 0.5 ppm), also showed virucidal and haemolytic activity. In general, 21,22-diacylation appeared to be associated with a virucidal (reduction factor of the viral titer > or = 10(3) at 50 microg/ml) and haemolytic activity (HC(50) < or = 1 microg/ml).

New acylated triterpenoid saponins from Maesa lanceolata

Ten new acylated triterpenoid saponins were isolated from the leaves of Maesa lanceolata. For their structure elucidation extensive use was made of homo- and heteronuclear 2D NMR techniques such as COSY, NOESY, HSQC and HMBC. All saponins identified contained the same tetraglycosidic side chain, but the triterpenoid moiety showed a variable esterification pattern. Monoester, diester and triester derivatives were present. Maesasaponin I was a 21-monoester derivative, i.e. {3β- O-[α- l-rhamnopyranosyl-(1→2)-β- d-galactopyranosyl-(1→3)]-[β- d-galactopyranosyl-(1→2)]-β- d-glucuronopyranosyl}-21β-angeloyloxy-13β,28-oxidoolean-16α, 22α, 28α-triol. Maesasaponins III, IV 3, V 3 and VI 2 had an additional acetyl, propanoyl, n-butanoyl and angeloyl substituent, respectively, in position 22. Maesasaponins II, IV 2, V 2, VI 3 and VII 1 were characterised as the 16-acetyl derivatives of maesasaponins I, III, IV 3, V 3 and VI 2, respectively. Structures of saponins previously reported in M. lanceolata had to be revised.

Carboxylic acid microbial metabolites of the natural benzoquinone, maesanin

Maesanin (1) is a naturally occurring bioactive benzoquinone isolated from the fruits of Maesa lanceolata (Myrsinaceae). Three carboxylic acid metabolites of maesanin were isolated in the course of a prospective microbial transformation study. The first metabolite, 2, was produced by Lipomyces lipofer ATCC 10742 and was characterized as (Z)-15-(2'-hydroxy-5'-methoxy-3', 6'-dioxocyclohexa-1',4'-dienyl)pentadec-5-enoic acid. Metabolites 3 and 4 were produced by Rhodotorula rubra ATCC 20129 and were characterized as 6-(2'-hydroxy-5'-methoxy-3',6'-dioxocyclohexa-1', 4'-dienyl)hexanoic acid and 4-(2'-hydroxy-5'-methoxy-3', 6'-dioxocyclohexa-1',4'-dienyl)butanoic acid, respectively.

Screening of seven selected Rwandan medicinal plants for antimicrobial and antiviral activities

Aqueous EtOH (80%) extracts of seven plants used by Rwandan traditional healers to treat infections, were screened for antibacterial, antifungal, and antiviral activities. Only two of the selected plants showed a true antiviral activity against herpes simplex virus type 1, while all of them exhibited virucidal properties against several enveloped viruses including herpes simplex, measles, Semliki forest, and vesicular stomatitis viruses. Four plants were diversely active against Gram-positive bacteria, two of these showing bactericidal effect against the acid-fast Mycobacterium fortuitum. None of the selected plants was active against Gram-negative bacteria or the yeast Candida albicans. From a bioassay-guided fractionation procedure using herpes simplex virus type 1 as the target model, a virucidal mixture, the maesasaponin mixture A, was isolated from the MeOH extract of Maesa lanceolata. The maesasaponin mixture A exhibited a virucidal activity against herpes simplex types 1 and 2, and vesicular stomatitis viruses.

Alkylated benzoquinone derivatives from Maesa lanceolata

Five new alkylated benzoquinones were isolated as methyl ether derivatives from a complex mixture containing alkylated hydroxy benzoquinones, obtained from the fruits of Maesa lanceolata. The structures of the benzoquinones, named, 2-acetoxy-5-methoxy-6-methyl-3-tridecyl-1, 4-benzoquinone, 2-methoxy-5-acetoxy-6-methyl-3-tridecyl-1, 4-benzoquinone, 2-acetoxy-5-methoxy-6-methyl-3- [ ( z)-10′-pentadecenyl]-1,4-benzoquinone, 2-methoxy-5-acetoxy-6-methyl-3- [ ( z)-10′-pentadecenyl-1, 4-benzoquinone and 2,5-di- methoxy-6-methyl-3-tridecyl-1,4-benzoquinone, were based on 1 H and 13 C NMR data, mainly 2D NMR experiments, including 1 H– 13 C HMBC correlations, as well as chemical derivatization.

Separation of a triterpenoid saponin mixture from Maesa lanceolata: semipreparative reversed-phase wide pore high performance liquid chromatography with temperature control

A mixture of triterpenoid saponins derived from the dried leaves of Maesa lanceolata was separated, without structure deterioration, in its components. Seven fractions (I–VII) of high molecular weight (1234–1358) saponins were obtained on a semipreparative scale using wide pore reversed-phase high performance liquid chromatography with an acetonitrile–trifluoroacetic acid (500:0.3 w/w)–water–trifluoroacetic acid (391:0.3, w/w) gradient from 35 to 56% in 30 min. The mobile phase was cooled in an ice bath (0°C) during chromatography in order to prevent bubble formation and to improve the quality of the separation. Freeze-dried fractions IV, V, VI and VII were further separated using solvent systems developed for each of the fractions. Fourteen pure triterpenoid saponins were isolated in this way and their molar weight determined.

Evaluation of biological activities of triterpenoid saponins from Maesa lanceolata.

From a bioassay-guided fractionation procedure using Herpes simplex virus type 1 as the target model, a virucidal saponin mixture (maesasaponin mixture B) was isolated from the MeOH extract of leaves of Maesa lanceolata. The maesasaponin mixture B consisted of six homologous oleanane-type triterpenoid saponins 1-6, identified by 1H, 13C, and 2D NMR spectroscopy and mass spectrometry. The maesasaponin mixture B (1-6) showed several biological activities expected for saponins. It exhibited a moderate virucidal activity against enveloped viruses. The maesasaponin mixture B (1-6) was tested for further properties. The saponin mixture was found to be highly hemolytic and molluscicidal: it hemolyzed 50% of human erythrocytes (1% suspension) at a concentration estimated at 1.6 microg/mL and exerted against Biomphalaria glabrata snails a severe toxic effect with LD95 and LD50 values of 4.1 and 2.3 ppm, respectively. In addition, the maesasaponin mixture B (1-6) showed moderate fungistatic and antimutagenic properties. The evaluation of these diverse activities is described.

New Dialkyl Benzoquinones from Fruits ofMyrsineafricanaL andMaesalanceolata, Forsk

Abstract Two new natural benzoquinones, 2,5-dihydroxy-3-methyl-6-undecyl-1,4-benzoquinone (1, muketanin) and 2-O-methyl-muketanin (2) have been isolated from fruits of Myrsine africana and Maesa lanceolata respectively.

Triterpenoid saponins from Maesa lanceolata

Six new homologous triterpenoid saponins were isolated from the methanol extract of the leaves of Maesa lanceolata and characterized as 3β-O-[α- l-rhamnopyranosyl(1 → 2)-β- d-galactopyranosyl(1 → 3)]-[β- d-galactopyranosyl(1 → 2)]-β- d-glucuronopyranosides of 22α-angeloyloxy-13β,28-oxydo-16α-propanoyloxyolean-21β,28α-diol, 22α-angeloyloxy-16α-butanoyloxy-13β,28-oxydoolean-21β,28α-diol, 16α,22α-diangeloyloxy-13β,28-oxydoolean-21β,28α-diol, 22α-angeloyloxy-13β,28-oxydo-16α-(2-methyl-butanoyloxy)-olean-21β,28α-diol, 21β-acetoxy-22α-angeloyloxy-13β,28-oxydo-16α-propanoyloxyolean-28α-ol, 21β-acetoxy-22α-angeloyloxy-16α-butanoyloxy-13β,28-oxydoolean-28α-ol. The structures were established on the basis of chemical and spectral evidence.

Seed Dispersal Effectiveness by Two Bulbuls on Maesa lanceolata, an African Montane Forest Tree

We examined the effectiveness with which two common understory birds, Andropadus latirostris and A. tephrolaemus (Pycnonotidae), dispersed seeds of a tropical pioneer forest tree, Maesa lanceolata (Myrsinaceae). Relative dispersal effectiveness of each species was assessed in terms of quantity and quality of seed dispersal. The number of seeds dispersed was examined by quantifying the tree visitation frequency, duration of time in the tree and number of fruits ingested, and probability that the bird would deposit seeds under the parent tree. The quality of seed dispersal was examined using defecation frequency, number of seeds defecated through time following ingestion of a cohort of 20 fruits, seed viability after passage through the gut, and general diet analysis. Andropadus tephrolaemus and A. latirostris were the most common visitors to M. lanceolata and accounted for 49.1 percent and 17.3 percent of all animal visits to the tree, respectively. The mean (and standard deviation) residence times in the tree were 2.82 ? 1.65 min for A. tephrolaemus and 3.14 ? 1.70 min for A. latirostris. Individuals of both species ate estimated 23 to 25 fruits per visit (3-20 seeds/fruit). Mean minimum seed passage times were 17.8 ? 1.93 min for A. tephrolaemus and 12.9 ? 0.80 min for A. latirostris. Seeds were viable after passing through the birds' gut. The majority of seeds passed through the gut within 20 min of the first defecation that contained seeds, and nearly all seeds passed within 80 min of ingestion. Mean time between defecations was 2.6 min for A. tephrolaemus and 2.2 min for A. latirostris. Frequency of return to the tree combined with the short tree residence times and defecation rates suggest that both species are unlikely to defecate more than 5 percent or 10 percent of seeds under the parent tree. Both species consistently dispersed most seeds away from the parent tree; A. tephrolaemus may be a more important disperser for the tree, however, because of its higher visitation rate.

Structure of maesaquinone

Structure of a benzoquinone, maesaquinone, isolated from Maesa lanceolata (Myrsinaceae), has been characterized as 2,5-dihydroxy-3-( Z)-10′-pentadecenyl-6-methyl-1,4-benzoquinone ( 1) by means of spectroscopic method. It has been found to exhibit in vitro cytotoxicity against several solid tumor cells. Structure of a benzoquinone, maesaquinone, isolated from Maesa lanceolata (Myrsinaceae), has been characterized as 2,5-dihydroxy-3-( Z)-10′-pentadecenyl-6-methyl-1,4-benzoquinone by means of spectroscopic method. The 13C NMR spectrum of maesaquinone showed only four higher values of chemical shifts due to the very rapid interconversion between the exchange forms. Maesaquinone has been found to exhibit in vitro cytotoxicity against several solid tumor cells.

Phytochemical Screening and Molluscicidal Potency of Some Zairean Medicinal Plants

A total number of 48 plants used in the Zairean pharmacopoeia were tested against molluscan intermediate hosts of schistosomiasis and fascioliasis. Aqueous and ethanolic extracts from five plants: Maesa lanceolata, Chenopodium ugandae, Asparagus racemosus, Phyllanthus nummulariifolius and Crinum zeylanicum , exhibited high mortality rate (100%) against Biomphalaria pfeifferi and Lymnaea natalensis. Their LC 50 was respectively 0.1, 5, 5, 10 and 50 mg ml -1 for B. pfeifferi and 0.5, 5, 1, 10 and 10 mg ml -1 for L. natalensis. The activities are attributed to the presence of terpenoids, steroids and saponins in the plant extracts. Except for the extracts from Ch. ugandae however, the plants have shown toxic effect on fishes and aquatic insects.

Potentiation by polygodial of the respiration inhibiting activity of maesanin in Candida utilis.

Maesanin, a metabolite isolated from the fruit of Maesa lanceolata (Myrsinaceae), was devoid of antifungal activity. However, when maesanin was combined with sub-inhibitory concentrations of a sesquiterpene dialdehyde polygodial known to affect the fungal cell membrane, antifungal activity was observed. The synergistic growth inhibition in malt extract medium differed according to fungal species. Among the yeasts tested, Candida utilis was shown to be susceptible to the combination of maesanin and polygodial, but Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Hansenula anomala were not. Synergistic action was also observed in the inhibition of cellular respiration of C. utilis. In mitochondrial preparations from C. utilis or rat liver, maesanin alone significantly inhibited NADH oxidase, succinate oxidase, NADH-cytochrome c reductase, succinate-cytochrome c reductase, and succinate-dichlorophenol-indophenol reductase. Polygodial alone had no inhibitory effect on the respiratory chain enzymes. These results suggest that the synergistic effect of polygodial is due to an increased permeability of maesanin through the cell membrane. The antifungal activity of maesanin in combination with polygodial appears to result from respiratory inhibition with its site of action near coenzyme Q of the mitochondrial electron transport system.

ChemInform Abstract: Isolation, Structure and Synthesis of Maesanin (IX), a Host Defense Stimulant from an African Medicinal Plant Maesa lanceolata.

ChemInformVolume 18, Issue 43 Natural Products ChemInform Abstract: Isolation, Structure and Synthesis of Maesanin (IX), a Host Defense Stimulant from an African Medicinal Plant Maesa lanceolata. I. KUBO, I. KUBO Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorM. KIM, M. KIM Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorI. GANJIAN, I. GANJIAN Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorT. KAMIKAWA, T. KAMIKAWA Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorY. YAMAGIWA, Y. YAMAGIWA Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this author I. KUBO, I. KUBO Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorM. KIM, M. KIM Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorI. GANJIAN, I. GANJIAN Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorT. KAMIKAWA, T. KAMIKAWA Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this authorY. YAMAGIWA, Y. YAMAGIWA Chem. Dep., Victoria Univ., Manchester M13 9PL, U. K.Search for more papers by this author First published: October 27, 1987 https://doi.org/10.1002/chin.198743359AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue43October 27, 1987 RelatedInformation

Isolation, structure and synthesis of maesanin, a host defense stimulant from an african medicinal plant [formula omitted][formula omitted

The isolation, characterization and an efficient synthesis of maesanin 1, a host defense stimulant isolated from an African medicinal plant Maesa lanceolata , is reported.

ChemInform Abstract: ISOLATION, STRUCTURE AND SYNTHESIS OF MAESANIN, A HOST DEFENSE STIMULANT FROM AN AFRICAN MEDICINAL MAESA LANCEOLATA

Chemischer InformationsdienstVolume 15, Issue 1 Isocyclic Compounds ChemInform Abstract: ISOLATION, STRUCTURE AND SYNTHESIS OF MAESANIN, A HOST DEFENSE STIMULANT FROM AN AFRICAN MEDICINAL MAESA LANCEOLATA I. KUBO, I. KUBOSearch for more papers by this authorT. KAMIKAWA, T. KAMIKAWASearch for more papers by this authorI. MIURA, I. MIURASearch for more papers by this author I. KUBO, I. KUBOSearch for more papers by this authorT. KAMIKAWA, T. KAMIKAWASearch for more papers by this authorI. MIURA, I. MIURASearch for more papers by this author First published: January 3, 1984 https://doi.org/10.1002/chin.198401165Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume15, Issue1January 3, 1984 RelatedInformation

Isolation, structure and synthesis of maesanin, a host defense stimulant from an African medicinal platn maesa lanceolata

The isolation, characterization and an efficient synthesis of maesanin 1 , a host defense stimulant isolated from an African medicinal plant Maesa lanceolata is reported.