Bufadienolides from bulbs of Urginea lydenburgensis (Hyacinthaceae: Urgineoideae)

Bulbs of the ethnomedicinal hyacinthac Urginea lydenburgensis have yielded two bufadienolides, 16beta-acetoxy-3beta,14beta-dihydroxy-19-formyl-bufa-4,20,22-trienolide (scillicyanosidin) and 4beta,8beta,11alpha,14beta-tetrahydroxybufa-5,20,22-trienolide-12-one, 2alpha,3beta-O-4,6-dideoxy-L-glucose (lydenburgenin).     

Bufadienolides from Drimia robusta and Urginea altissima (Hyacinthaceae)

The bufadienolides, 6beta-acetoxy-3beta,8beta,12beta,14beta-tetrahydroxybufa-4,20,22-trienolide (12beta-hydroxyscillirosidin) (1) and 14beta-hydroxybufa-4,20,22-trienolide 3beta-O-[alpha-L-rhamnopyranosyl-[(1-->4)-beta-D-glucopyranosyl]-(1-->3)-alpha-L-rhamnopyranoside] (urginin) (2) were isolated from Drimia robusta and Urginea altissima, respectively.     

Cytotoxic triterpenes from the aerial roots of Ficus microcarpa

Six triterpenes, 3beta-acetoxy-12,19-dioxo-13(18)-oleanene (1), 3beta-acetoxy-19(29)-taraxasten-20alpha-ol (2), 3beta-acetoxy-21alpha,22alpha-epoxytaraxastan-20alpha-ol (3), 3,22-dioxo-20-taraxastene (4), 3beta-acetoxy-11alpha,12alpha-epoxy-16-oxo-14-taraxerene (5), 3beta-acetoxy-25-methoxylanosta-8,23-diene (6) along with nine known triterpenes, 3beta-acetoxy-11alpha,12alpha-epoxy-14-taraxerene (7), 3beta-acetoxy-25-hydroxylanosta-8,23-diene (8), oleanonic acid (9), acetylbetulinic acid (10), betulonic acid (11), acetylursolic acid (12), ursonic acid (13), ursolic acid (14), and 3-oxofriedelan-28-oic acid (15) were isolated from the aerial roots of Ficus microcarpa, and their structures elucidated by spectroscopic methods. The in vitro cytotoxic efficacy of these triterpenes was investigated using three human cancer cell lines, namely, HONE-1 nasopharyngeal carcinoma, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells. Compound 8 and pentacyclic triterpenes 9-15 possessing a carboxylic acid functionality at C-28 showed significant cytotoxic activities against the aforementioned cell lines and gave IC50 values in the range 4.0-9.4 microM.     

Alkaloids from Dictyoloma vandellianum: their chemosystematic significance

The dichloromethane extract from leaves of Dictyoloma vandellianum afforded five alkaloids 2-(14'-hydroxy-14',15'-dimethylhexadecanyl)-4-quinolone, 2-(12'-hydroxy-12'-methyltridecanyl)-3-methoxy-4-quinolone, 2-(12'-hydroxy-12'-methyltridecanyl)-4-quinolone, 2-(14'-hydroxy-14',15'-dimethylhexadecanyl)-3-methoxy-4-quinolone, 6-methoxydictyolomide A, besides the known alkaloid 8-methoxyflindersine and beta-sitosterol. The presence of 2-alkyl-4(1H)-quinolones in D. vandellianum shows strong similarities with the Zanthoxyleae, which contains several 2-alkyl-4-quinolones. Thus, the Dictyolomatoideae apparently occupies a position between the proto-Rutaceae genera and the Spathelioideae, but close to the Zanthoxyleae.     

Steryl esters and phenylethanol esters from Syringa komarowii

Three new steryl esters and a new phenylethanol ester, together with 22 known compounds were isolated from the aqueous ethanolic extract of the whole plants of Syringa komarowii. The new compounds were elucidated as stigmastane-3beta,6alpha-diol 3-O-tetradecanoate (1), stigmastane-3beta,6alpha-diol 3-O-palmitate (2), stigmastane-3beta,6alpha-diol 3-O-stearate (3), and 2-(4-hydroxyphenyl)-ethyl dotriacontanoate (4) on the basis of extensive spectral data and chemical evidences.     

Chemotaxonomic relevance of cardenolides in Urginea fugax

In a chemotaxonomic approach the investigation of a methanolic extract of bulbs of Urginea fugax (MORIS) STEINH. resulted in the detection of several cardenolides. The structure of a novel compound, named fugaxin (1), was established as 12alpha,14beta-dihydroxy-2alpha,3beta-(tetrahydro-3',5'-dihydroxy-4'-methoxy-6'-methyl-2H-pyran-2',4'-diylbisoxy)-card-4,20-dienolide by extensive NMR spectroscopic studies including 2D-NMR techniques (COSY, HSQC, HMQC) and selective 1D experiments (NOE, TOCSY) as well as HR-ESI-MS. The chemotaxonomic relevance of the occurrence of cardenolides in the genus Urginea is discussed.     

Chemical constituents of leaves and stem bark of Plumeria obtusa

The continued studies on the constituents of the fresh leaves and stem bark of Plumeria obtusa Linn. have led to the isolation and characterization of four new triterpenoids, dammara-12,20(22)Z-dien-3-one (1), dammara-12,20(22)Z-dien-3beta-ol (2), olean-12-en-3beta,27-diol (3), and 27-hydroxyolean-12-en-3-one (4) and 12 known compounds, which included eight triterpenoids; dammara-3beta,20(S),25-triol (5), urs-12-en-3beta-hydroxy-27-Z-feruloyloxy-28-oic acid (6), 3beta-hydroxyolean-12-en-28-oic acid (7), 3beta,27-dihydroxylupan-29-ene (8), 3beta-hydroxylupan-29-en-28-oic acid (9), 3beta-hydroxyursan-12-en-28-oic acid (11), 3beta-hydroxy-27-p-coumaroyloxy-olea-12-en-28-oic acid (12) and urs-12-en-3-one (15); an iridoid 1alpha-plumieride (10); a cardenolide 3alpha,14beta-dihydroxy-17beta-card-20(22)-enolide (13); a fatty acid ester methyl n-octadecanoate (14) and a steroid 3beta-hydroxy-delta5-stigmastane (16). The new constituents were characterized through spectroscopic studies including 1D (1H and 31C NMR) and 2D (COSY-45, NOESY, J-resolved, HMQC and HMBC) NMR and chemical transformations. This is the first report on the isolation of dammarane triterpenoids from P. obtusa. Compounds 5 and 6 are hitherto unreported from P. obtusa. The known compounds were identified by comparison of their spectral data with those reported in the literature.     

Polyhydroxylated steroids from the soft coral Sinularia dissecta

A repeated silica gel column chromatography followed by HPLC purification on the methanol extract of marine soft coral Sinularia dissecta, resulted in the isolation of fifteen polyhydroxylated steroids (1-15), involving six new C-18 functionalized steroids, 3beta-acetoxy-1alpha,11alpha-dihydroxygorgost-5-en-18-oic acid (1), gorgost-5-en-1alpha,3beta,11alpha,18-tetrol (2), 18-acetoxy-1alpha,3beta,11alpha-trihydroxygorgost-5-ene (3), 24(S)-3beta-acetoxy-1alpha, 11alpha-dihydroxyergost-5-en-18-oic acid (4), 24(S)-ergost-5-en-1alpha,3beta,11alpha,18-tetrol (5), and dissectolide (6). The structures of the new compounds were determined on the basis of extensive spectroscopic data (IR, MS, (1)H and (13)C NMR, HMQC, HMBC, and NOESY) analysis. Compound 6 was found as an unusual sterol bearing a lactone functionality.     

Coincident isolation of a novel homoisoflavonoid from Resnova humifusa and Eucomis montana (Hyacinthoideae: Hyacinthaceae)

We report on the first phytochemical investigation of a member of the African genus Resnova (Hyacinthoideae: Hyacinthaceae). From the dichloromethane extract of the bulbs of both Resnova humifusa and Eucomis montana (Hyacinthoideae: Hyacinthaceae) a novel 3-benzyl-4-chromanone homoisoflavonoid, 5,6-dimethoxy-7-hydroxy-3-(4′-hydroxybenzyl)-4-chromanone, was isolated. A further 11 known homoisoflavonoids were also identified, the 12 in total presenting a clear biosynthetic sequence. Eight of the 12 compounds found were common to both species.     

Sesquiterpenes from Warburgia ugandensis and their antimycobacterial activity

The dichloromethane extract of the stem bark of Warburgia ugandensis afforded three new coloratane sesquiterpenes, namely: 6alpha,9alpha-dihydroxy-4(13),7-coloratadien-11,12-dial (1), 4(13),7-coloratadien-12,11-olide (2), and 7beta-hydroxy-4(13),8-coloratadien-11,12-olide (3), together with nine known sesquiterpenes, i.e., cinnamolide-3beta-acetate (4), muzigadial (5), muzigadiolide (6), 11alpha-hydroxymuzigadiolide (7), cinnamolide (8), 7alpha-hydroxy-8-drimen-11,12-olide (9), ugandensolide (10), mukaadial (11), ugandensidial (12), and linoleic acid (13). Their structures were assigned on the basis of 1D and 2D-NMR spectroscopic and GC-MS analysis. The compounds were examined for their antimycobacterial activity against Mycobacterium aurum, M. fortuitum, M. phlei and M. smegmatis; and the active constituents showed MIC values ranged from 4 to 128 microg/ml compared to the antibiotic drugs ethambutol (MIC ranged from 0.5 to 8 microg/ml) and isoniazid (MIC ranged from 1 to 4 microg/ml).     

Diterpenes and sesquiterpenes from the bark of Taxus yunnanensis

Two taxane-type diterpenes, 10beta-acetoxy-2alpha,5alpha,7beta,9alpha-tetrahydroxytaxa-4(20),11-dien-13-one and 2alpha-acetoxy-9alpha-benzoyloxy-5alpha,7beta,10beta,15-tetrahydroxy-11(15-->1)- abeotaxa-4(20),11-dien-13-one, and two new drimane-type sesquiterpenes, 1beta-acetoxy-7-drimen-11alpha-ol-12,11-lactone and 1beta-acetoxy-11,12-epoxy-6-drimen-8alpha,11alpha-diol, were isolated from the bark of Taxus yunnanensis together with 35 known taxane-type diterpenes, a known drimane-type sesquiterpene and a known flavanone.     

Terpenoids from Tripterygium doianum (Celastraceae)

The extract of Tripterygium doianum (Celastraceae) afforded three triterpenoids [3beta-acetoxy-11-ursen-13alpha,30-olide, 25-chloro-24-hydroxytirucall-7-en-3-one and tirucall-7-en-3,24-dione], two sesquiterpenoids [5alpha-acetoxy-1beta,8alpha-bis-cinnamoyl-4alpha-hydroxydihydroagarofuran and 5alpha-acetoxy-1beta-benzoyl-8alpha-cinnamoyl-4alpha-hydroxydihydroagarofuran] and nine known triterpenoids. Their structures were established based on spectroscopic studies.     

Potential anti-allergic ent-kaurene diterpenes from the bark of Suregada multiflora

Two ent-kaurene diterpenes, ent-16-kaurene-3beta,15beta,18-triol (1) and ent-3-oxo-16-kaurene-15beta,18-diol (2), were isolated from a dichloromethane extract of the bark of Suregada multiflora along with five known diterpenes:ent-16-kaurene-3beta,15beta-diol (3), abbeokutone (4), helioscopinolide A (5), helioscopinolide C (6) and helioscopinolide I (7). Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1-7 possessed appreciable anti-allergic activities in RBL-2H3 cells model with IC50 values ranging from 22.5 to 42.2 microM.     

ent-Kauranoid derivatives from Sideritis moorei

Seven new ent-kauranoid derivatives ent-7alpha,18-dihydroxykaur-16-en-3-one, ent-18-acetoxy-3beta,7alpha-dihydroxykaur-15-en-17-al, ent-3beta-acetoxy-7alpha,18-dihydroxykaur-15-en-17-al, ent-18-acetoxy-3beta,7alpha,17-trihydroxykaur-15-ene, ent-3beta-acetoxy-7alpha,17,18-trihydroxykaur-15-ene, ent-18-acetoxy-3beta,7alpha,17-trihydroxy-15beta,16beta-epoxykaurane and ent-3beta-acetoxy-7alpha,17,18-trihydroxy-15beta,16beta-epoxykaurane have been isolated from Sideritis moorei. The structures of these compounds have been established by spectroscopic means and chemical correlations.     

Novel polyhydroxysterols from the Red Sea marine sponge Lamellodysidea herbacea

Chemical investigation of the dichloromethane extract of the Red Sea marine sponge Lamellodysidea herbacea led to the isolation of four novel polyhydroxysteroids: cholesta-8-en-3beta,5alpha,6alpha,25-tetrol (1), cholesta-8(14)-en-3beta,5alpha,6alpha,25-tetrol (2), cholesta-8,24-dien-3beta,5alpha,6alpha-triol (3), and cholesta-8(14),24-dien-3beta,5alpha,6alpha-triol (4). Their structures were identified through 1D and 2D NMR studies. Relative stereochemistries were established by analysis of chemical shifts, coupling constants, and NOESY correlations. Compounds 3-4 showed antifungal activity against Candida tropicalis, with an inhibition diameter of 13 and 11 mm at 10 microg/disc, respectively.     

Antioxidant constituents of Nymphaea caerulea flowers

As part of an ongoing search for antioxidants from medicinal plants, 20 constituents were isolated from the Nymphaea caerulea flowers, including two 2S,3S,4S-trihydroxypentanoic acid (1), and myricetin 3-O-(3'-O-acetyl)-alpha-L-rhamnoside (2), along with the known myricetin 3-O-alpha-L-rhamnoside (3), myricetin 3-O-beta-D-glucoside (4), quercetin 3-O-(3'-O-acetyl)-alpha-L-rhamnoside (5), quercetin 3-O-alpha-L-rhamnoside (6), quercetin 3-O-beta-D-glucoside (7), kaempferol 3-O-(3'-O-acetyl)-alpha-L-rhamnoside (8), kaempferol 3-O-beta-D-glucoside (9), naringenin (10), (S)-naringenin 5-O-beta-D-glucoside (11), isosalipurposide (12), beta-sitosterol (13), beta-sitosterol palmitate (14), 24-methylenecholesterol palmitate (15), 4alpha-methyl-5alpha-ergosta-7,24(28)-diene-3beta,4beta-diol (16), ethyl gallate (17), gallic acid (18), p-coumaric acid (19), and 4-methoxybenzoic acid (20). The structures were determined by spectroscopic means. Compounds were tested for antioxidant activity and nine compounds 2-7, 11, 12 and 18 were considered active with IC(50) of 1.16, 4.1, 0.75, 1.7, 1.0, 0.34, 11.0, 1.7 and 0.95 microg/ml, respectively, while 1 was marginally active (IC(50)>31.25 microg/ml). The most promising activity was found in the EtOAc fraction (IC(50) 0.2 microg/ml). This can be attributed to the synergistic effect of the compounds present in it.     

Oleanane-type triterpenes of Embelia schimperi leaves

An investigation of an ethyl acetate extract of Embelia schimperi leaves has led to the isolation of 10 oleanane-type triterpenes characterized as 3beta,16alpha-di-O-acetyl-13beta, 28-epoxyoleanane (1), 3beta-acetyl-16-oxo-13beta, 28-epoxyoleanane (2), 3beta-acetyl-16alpha-hydroxy-13beta, 28-epoxyoleanane (3), 3beta-acetyl-16alpha-hydroxyoleanane-13beta, 28-olide (4), 3beta-acetyl-28-hydroxy-16-oxo-12-oleanene (5), 3beta, 28-di-O-acetyl-16alpha-hydroxy-12-oleanene (6), 3beta-acetyl-11alpha, 28-dihydroxy-16-oxo-12-oleanene (7), 3beta, 11alpha, 16alpha, 28-tetrahydroxy-12-oleanene (8), 3beta-acetyl-16alpha, 28alpha-dihydroxy-13beta, 28-oxydooleanane (9) and 3beta, 28alpha-dihydroxy-16-oxo-13beta, 28-oxydooleanane (10). The known compounds isolated from the same extract included 3beta, 16alpha-dihydroxy-13beta, 28-epoxyoleanane (protoprimulagenin A) (11), 3beta-hydroxy-16-oxo-13beta, 28-epoxyoxyoleanane (aegicerin) (12), 3, 16-dioxo-13beta, 28-epoxyoleanane (embilionone) (13), 3beta, 28-dihydroxy-16-oxo-12-oleanene (schimperinone) (14), taraxerone (15), taraxerol (16) and stigmasterol (17). Structure elucidations were carried out spectroscopically.     

ent-Clerodane diterpenes and other constituents from the liverwort Adelanthus lindenbergianus (Lehm.) Mitt

Eleven ent-clerodanes, 13-hydroxy-cis-ent-cleroda-3,14-diene, 15-hydroxy-cis-ent-cleroda-3,13(E)-diene, 1beta,12:15,16-diepoxy-cis-ent-cleroda-13(16),14-dien-18alpha,6alpha-olide, 8beta,12:15, 16-diepoxy-cis-ent-cleroda-13(16),14-dien-18alpha,6alpha-olide, 1beta,16:15,16-diepoxy-cis-ent-cleroda-12,14-dien-18alpha,6alpha-olide, 7beta,12:8beta,12-diepoxy-15-hydroxy-cis-ent-cleroda-13-en-16,15:18alpha,6alpha-diolide, 7beta,12:8beta,12-diepoxy-16-hydroxy-cis-ent-cleroda-13-en-15,16:18alpha,6alpha-diolide, 1alpha-acetoxy-8beta,12-epoxy-15-hydroxy-cis-ent-cleroda-13-en-16,15:18alpha,6alpha-diolide, 1beta,12-epoxy-16-hydroxy-cis-ent-cleroda-13-en-15,16:18alpha,6alpha-diolide, 8beta,12-epoxy-15-hydroxy-trans-cleroda-13-en-16,15:18alpha,6alpha-diolide, 8beta,12-epoxy-16-hydroxy-trans-cleroda-13-en-15,16:18alpha,6alpha-diolide along with the known clerodane diterpenes anastreptin and orcadensin have been isolated from the liverwort Adelanthus lindenbergianus (Lehm.) Mitt. Furthermore, three eudesmane sesquiterpenes together with the known (-)-1beta,10-epoxyaristolan, 3,4-seco-4(23),20(29)-lupadien-3,28-dicarboxylic acid dimethyl ester and two acetophenone derivatives were identified by spectroscopic methods, essentially MS and NMR experiments.     

Phenolic derivatives from Wigandia urens with weak activity against the chemokine receptor CCR5

Three compounds, 2,3-dihydroxy-4-methoxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran (1), 8-methoxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-6-ol (2) and 4-methoxy-3-(3-methyl-2-butenyl)-benzoic acid (3), have been isolated from Wigandia urens. The structures of compounds 1, 2 and 3 were determined from spectroscopic data and showed activity in a CCR5 assay with IC(50) values of 33, 46 and 26 muM respectively.     

Anti-plasmodial activities and X-ray crystal structures of rotenoids from Millettia usaramensis subspecies usaramensis

The dichloromethane extract of the stem bark of Millettia usaramensis subspecies usaramensis showed anti-plasmodial activity against the chloroquine sensitive (D6) and chloroquine resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the extract led to the identification of a new rotenoid, (6aR,12aS)-2,3-methylenedioxy-9-methoxy-8-(3,3-dimethylallyl)-12a-hydroxyrotenoid (trivial name, usararotenoid C) along with known flavonoids (usararotenoid A, 12a-epimillettosin, 6a,12a-dehydromillettone, barbigerone and 4'-O-geranylisoliquiritigenin) as the anti-plasmodial principles. The structures were determined by spectroscopic analyses. CD and X-ray analyses established absolute configurations.