Efecto citotóxico de diterpenos derivados del ácido ent-kaureno aislados de Coespeletia moritziana (Sch. Bip. ex Wedd.) Cuatrec / Cytotoxic effect of ent-kaurene acid-derived diterpenes isolated from Coespeletia moritziana (Sch. Bip. Ex Wedd.) Cuatrec

The objective of the work was to study the cytotoxic effect of ent-kaurene acid derivatives obtained from Coespeletia moritziana (Sch. Bip. Ex Wedd.) Cuatrec., After analysis by GC/MS, IR and NMR. Isolating: kaurenic acid (I), grandifloric acid (II), 15-α-hydroxy kaurenic acid (III), 15 α-acetoxy-kaur 16-en-19-oic acid (IV), Kaurenol (V); and by hemisynthesis: 15,16-epoxy-17-acetoxy-kauran 19-oic acid (VI), 15-oxo-ent-kaur-16-en-19-oic acid (VIII), ester 2,3,4,6 -15-oxo-kaur-16-en-19-oic acid acetyl α-D-pyranosyl tetra-tetra (VII). Cytotoxicity was tested in human cancer cell lines: uterus (HeLa), lung (A-549), breast (MCF-7), African green monkey kidney non-tumor line (Vero) and human peripheral blood mononuclear cells (CMPS). Compound (I) was active against HeLa, A-549 and Vero. Compounds (II and VIII) showed moderate and good (IC50 ≤ 9 µM) cytotoxicity, respectively, against the five cell lines. Compound (V) showed moderate activity against A-549 and compound (VII), slight cytotoxicity against HeLa and A-549. Results that show the cytotoxic specificity of the isolated kaurenes and derivatives of Coespeletia moritzianaand their therapeutic potential.

El objetivo del trabajo fue estudiar el efecto citotóxico de derivados del ácido ent-kaureno obtenidos de Coespeletia moritziana (Sch. Bip. ex Wedd.) Cuatrec., previo análisis mediante GC/MS, IR y RMN. Aislandose: ácido kaurénico(I), ácido grandiflorénico (II), ácido 15-α-hidroxi kaurénico(III), ácido 15 α-acetoxi-kaur 16-en-19-oico (IV), Kaurenol (V); y por hemisíntesis: ácido 15,16-epoxi-17-acetoxi-kauran 19-oico (VI), ácido15-oxo-ent-kaur-16-en-19-oico (VIII), éster 2,3,4,6-tetra acetil α-D-piranosilo del ácido 15-oxo-kaur-16-en-19-oico (VII). La citotóxicidad fue ensayada en líneas celulares cancerosas humanas: útero (HeLa), pulmón(A-549), mama (MCF-7), línea no tumoral de riñón de mono verde africano (Vero) y células mononucleares humanas de sangre periférica (CMPS). El compuesto (I) resultó activo frente a HeLa, A-549 y Vero. Los compuestos (II y VIII), mostraron moderada y buena (IC50≤9µM) citotoxicidad respectivamente, frente a las cinco líneas celulares. El compuesto (V) presentó moderada actividad frente a A-549 y el (VII), leve citotoxicidad frente a HeLa y A-549. Resultados que evidencian la especificidad citotóxica de los kaurenos aislados y derivados de Coespeletia moritzianay su potencial terapéutico.

Oleanane-type glycosides from Pittosporum tenuifolium "variegatum" and P. tenuifolium "gold star".

The phytochemical study of two cultivars of Pittosporum tenuifolium Banks & Sol. ex Gaertn, "variegatum" and "gold star", led to the isolation of eight oleanane-type glycosides: seven previously undescribed and a known one. Their aglycons are oxygenated oleanane derivatives as barringtogenol C, camelliagenin A, hederagenin, and 22α-hydroxyoleanolic acid. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-21-O-angeloyl-22-O-acetylbarringtogenol C, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-21,22-di-O-angeloylbarringtogenol C, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-22-O-angeloylcamelliagenin A, 3-O-ß-D-glucopyranosyl-(1 â†’ 2)-[ß-D-glucopyranosyl-(1 â†’ 6)]-ß-D-glucopyranosyl-22-O-[(6-O-acetyl)-ß-D-glucopyranosyl]camelliagenin A, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinofuranosyl-(1 â†’ 4)]-ß-D-glucuronopyranosylhederagenin 28-O-ß-D-glucopyranosyl ester, 3-O-α-L-arabinofuranosyl-(1 â†’ 4)-ß-D-glucuronopyranosylhederagenin 28-O-ß-D-glucopyranosyl ester, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinofuranosyl-(1 â†’ 4)]-ß-D-glucuronopyranosyl-22α-hydroxyoleanolic acid 28-O-ß-D-glucopyranosyl ester, and the known ilexoside XLIX. These results represent a significative contribution to the chemotaxonomy of the genus Pittosporum, highlighting hederagenin-type saponins as chemotaxonomic markers of P. tenuifolium cultivars.

Chemical Composition and in vitro Antibacterial Activity of the Essential Oil of Verbesina negrensis from the Venezuelan Andes.

The composition and antimicrobial activity of the essential oil from Verbesina negrensis Steyerm. leaves is reported. Analysis was performed by GC/MS. Major constituents were α-pinene (43.1%), α-humulene (13.8%), Δ-cadinene (8.1%), limonene (4.6%) and bicyclogermacrene (4.2%). The essential oil showed in vitro activity against the Gram-positive bacteria Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212 (MIC 500 and 350 µL/mL respectively).

Volatile Constituents from the Flowers of Spathodea campanulata from the Venezuelan Andes.

The chemical composition is reported of the essential oil obtained by hydrodistillation of Spathodea campanulata P. Beauv. (Bignoniaceae) flowers collected in the Andes region of Venezuela. Thirty compounds were characterized, representing 96.5% of the total oil composition; benzyl benzoate (17.5%) was the major constituent. Others major components were a mixture of geranyl acetone with a-humulene (12.7%), ß-caryophyllene (9.5%), farnesyl acetone (6.0%), aromadendrene (4.3%), α-gurjunene (3.9%) and tricosane (3.7%). This is the first report related to the chemical composition of the essential oil of S. campanulata flowers.

Chemical composition of the essential oil from the leaves of Carapa guianensis collected from Venezuelan Guayana and the antimicrobial activity of the oil and crude extracts.

The essential oil obtained by hydrodistillation of Carapa guianensis Aubl. (Meliaceae) leaves was analyzed by GC-FID and GC-MS. Twenty-three components were identified, which made up 93.7% of the oil. The most abundant constituents were bicyclogermacrene (28.5%), alpha-humulene (17.2%), germacrene B (11.9%), and trans-beta-caryophyllene (9.9%). Antimicrobial activity of the essential oil, as well as the crude extracts of the leaves obtained by refluxing the dried leaves with n-hexane, dichloromethane, and methanol, was determined using the disc diffusion assay. Activity against Staphylococcus aureus ATCC 29923 and Enterococcus faecalis ATCC 29212 was only found for the essential oil and the methanolic extract, at minimal inhibitory concentrations (MIC) of 400 microg/mL and 50 microg/mL.

Steroidal saponins from the fruits of Solanum torvum.

Seven steroidal glycosides have been isolated from the fruits of Solanum torvum Swartz. Their structures were established by 2D NMR spectroscopic techniques ((1)H,(1)H-COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as (25S)-26-(ß-D-glucopyranosyloxy)-3-oxo-5α-furost-20(22)-en-6α-yl-O-ß-D-xylopyranoside (1), (25S)-26-(ß-D-glucopyranosyloxy)-3-oxo-22α-methoxy-5α-furostan-6α-yl-O-ß-D-xylopyranoside (2), (25S)-26-(ß-D-glucopyranosyloxy)-3ß-hydroxy-22α-methoxy-5α-furostan-6α-yl-O-α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranoside (3), (25S)-3ß-hydroxy-5α-spirostan-6α-yl-O-ß-D-xylopyranoside (4), (25S)-3-oxo-5α-spirostan-6α-yl-O-ß-D-xylopyranoside (5), (25S)-3ß-hydroxy-5α-spirostan-6α-yl-O-ß-D-glucopyranoside (6), (25S)-3ß,27-dihydroxy-5α-spirostan-6α-yl-O-ß-D-glucopyranoside (7).

Chemical composition and in vitro antibacterial activity of the essential oil of Phthirusa adunca from Venezuelan Andes.

In this paper, preliminary studies on the chemical characterization of Phthirusa adunca Meyer essential oil, obtained by hydrodistillation, is presented. The separation of the components was performed by GC-MS. Twenty-three compounds (94.5% of the sample) were identified of which the three major ones (76% of the sample) were beta-phellandrene (38.1%), germacrene D (26.8%) and beta-pinene (11.5%). The essential oil showed a broad spectrum of activity against Salmonella Typhi CDC 57 (100 microg/mL), Staphylococcus aureus ATCC 25923 (200 microg/mL), Enterococcus faecalis ATCC 29212 (250 microg/mL), Escherichia coli ATCC 25922 y Klebsiella pneumoniae ATCC 23357 (500 microg/mL). This is the first report on the composition and activity of the essential oil of this species.

Chemical composition of the essential oil from Carramboa littlei (Asteraceae).

The essential oil from the leaves of Carramboa littlei Aristeg. was isolated by hydrodistillation yielding 0.09%, w/v. The chemical composition was determined by GC-FID and GC-MS. Sixteen components were identified by comparison of their mass spectra with Wiley and NIST library data. The major constituents of the oil were germacrene-D (50.0%), bicyclogermacrene (4.8%) and ent-kaur-16-en-19-al (21.8%).

Steroidal saponins from the fruits of Cestrum ruizteranianum.

Seven spirostane and furostane-type glycosides were isolated from the aqueous methanolic extract of the fruits of Cestrum ruizteranianum and characterized mainly by 2D NMR spectroscopy and mass spectrometry. These known saponins belong to the delta5-spirostene and delta5-furostene series and are reported in this species for the first time.

Chemical composition of the essential oil from the bark Bursera tomentosa (Jacq) Tr & Planch / Composición química del aceite esencial de la corteza de Bursera tomentosa (Burseraceae) (Jacq) Tr & Planch

The bark of Bursera tomentosa was collected at full flowering stage in September 2002 at Cabudare, Lara State. The essential oil was isolated by hydrodistillation and it was analyzed by GC and GC/MS. Twenty eight components were identified which made up 90.1 percent of the oil. The main constituents of the essential oil were: spatulenol (11.4 percent, globulol (8.9 percent), epi alpha Cadinol (8.8 percent) and cis-ocimene (7.3 percent).

La corteza de Bursera tomentosa, fue recolectada en estado de floración en el mes de septiembre 2002 en Cabudare, Estado Lara. El aceite esencial fue obtenido por hidrodestilación y analizado por CG y CG/EM. Se identificó veinte y ocho compuestos que constituyen el 90.1por ciento del aceite. Los constituyentes mayoritarios del aceite esencial fueron spatulenol (11.4 por ciento), globulol (8.9 por ciento), epi-alfa-cadinol (8.8 por ciento) y cis-ocimeno (7.3 por ciento).

Volatile compounds from Tagetes pusilla (Asteraceae) collected from the Venezuela Andes.

The essential oil from the leaves of Tagetes pusilla Kunth (Asteraceae) collected from Mérida, Venezuela, was analyzed by GC/MS. A yield of 0.38% oil was obtained by hydrodistillation. Only two components, trans-anethole and 4-allylanisole were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base.

Chemical composition of the essential oil of leaves and roots of Ottoa oenanthoides (Apiaceae) from Mérida, venezuela.

Essential oils extracted by hydrodistillation from leaves and roots of Ottoa oenanthoides Kunth (Apiaceae) were analyzed by GC/MS. The oils, obtained in yields of 0.10% and 0.66%, respectively, each contained four compounds, which were identified from their mass spectra and retention indices (RI). The major compound identified was 2-methoxy-8-methyl-1,4-naphthalindione (59.9% leaves, and 62.8%, roots), followed by 7-methoxy-1-naphthol (18.3% leaves and 17.3% roots), 2-naphthalenol (18.6% leaves and 15.0% roots), and 3-methoxy-2-naphthalenol (3.1% leaves and 2.1% roots). To the best of our knowledge, this is the first time that naphthalene derivatives have been reported for any species of the Apiaceae family.

The volatile constituents of Salvia leucantha.

Salvia leucantha Cav. (Lamiaceae), native to Mexico, is found in Venezuela in parks and gardens. Hydrodistillation of the fresh leaves of this plant yielded 0.05% of essential oil. GC and GC/MS analyses permitted the identification of 30 compounds, which made up 95.9% of the oil. The most abundant constituents were bornyl acetate (24.1%), beta-gurjunene (14.8%), beta-caryophyllene (14.1%), dillapiol (11.0%) and bicyclogermacrene (8.9%).

Chemical composition and larvicidal activity of Eugenia triquetra essential oil from Venezuelan Andes.

The chemical constituents of the essential oil obtained by hydrodistillation of the leaves of Eugenia triquetra O. Berg, collected in Táchira State, Venezuela, were identified by GC-MS analysis. Twenty-six components, which made up 88.5% of the oil, were identified. The major constituents were linalool (17.5%), limonene (16.9%), alpha-pinene (11.6%), beta-pinene (8.7%), and p-cymene (3.7%). The essential oil was tested against third-instar larvae of Aedes aegypti, showing a LC50 value of 64.8 +/- 5.6 ppm.

Triterpene saponins from the fruits of Phytolacca rugosa (Phytolaccaceae).

Four known serjanic acid glycosides were isolated from the fruits of Phytolacca rugosa and characterized mainly by 2D NMR spectroscopy and mass spectrometry. This aglycon has a chemotaxonomic significance for the genus Phytolacca.

Analysis of chemical constituents of the volatile oil from leaves of Solanum bicolor.

The volatile components from the leaves of Solanum bicolor Roemer & Schultes, was obtained by hydrodistillation and was analizad by GC/MS. A total of 20 compounds, representing 96.3 % of the oil, were identified. The dominant compounds were trans-caryophyllene (23.2%), trans-2-pentadecene (22.6%), germacrene D (12.2%), biciclogermecrene (8.0%) and caryophyllene oxide (4.7%).

Chemical composition and antibacterial activity of the essential oil from fruits of Bursera tomentosa.

The hydrodistilled oil from the fruits of Bursera tomentosa, obtained in 0.2% yield, was analyzed by GC-MS. Nine components were identified, which made up 99.3% of the oil. The most abundant constituents were cis-ocimene (47.6%), n-nonane (28.2%) and germacrene-D (11.1%). The oil showed antibacterial activity against Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212) and Salmonella typhi (CDC 57), with MIC values of 80 microg/mL, 120 microg/mL and 100 microg/mL, respectively.

New steroidal alkaloids from Solanum hypomalacophyllum.

Two new steroidal alkaloids (1-2) have been isolated from the leaves and roots of Solanum hypomalacophyllum Bitter, respectively. Their structures have been elucidated as deacetoxysolaphyllidine-3-O-beta-D-glucopyranoside (1) and 4-keto-5,6-dihydro-(20S)-verazine (2). Furthermore, two known steroidal alkaloids, 20R-verazine and 20S-verazine, and the common secondary metabolites oleanolic acid and beta-sitosterol were isolated from the roots, whereas deacetoxysolaphyllidine was obtained from the leaves.

Chemical composition and antibacterial activity of the essential oil of Monticalia andicola (Asteraceae) collected in Venezuela.

The essential oil from the leaves of Monticalia andicola Turcz., collected in November 2008, was analyzed by GC/MS. A yield of 0.15% oil was obtained by hydrodistillation. Thirty-six components were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base. The major components were alpha-pinene (19.6%), beta-pinene (10.5%), alpha-longipinene (6.5%), delta-3-carene (6.2%), cyperene (5.4%) and beta-phellandrene (5.2%). The antibacterial activity of the essential oil was evaluated against Gram- positive (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212) and Gram-negative (Escherichia coli ATCC 25992, Klebsiella pneumoniae ATCC 23357, Pseudomonas aeruginosa ATCC 27853) bacteria, using the disc diffusion agar method. The results showed a broad spectrum of activity with minimal inhibitory concentration (MIC) values ranging from 10 to 150 microg/mL.

Chemical composition and antibacterial activity of the essential oil of Cordia verbenacea from the Venezuelan Andes.

The essential oil of Cordia verbenacea D.C. (Boraginaceae) that grows in Mérida-Venezuela was obtained by hydrodistillation from the aerial parts of the plant, yielding 0.21%. The oil was analyzed by GC-FID and GC-MS. Thirty one components which made up 94.3% of the oil were identified. The most abundant constituents found were: tricyclene (23.9%), bicyclogermacrene (11.7%), germacrene D (9.9%) and beta-caryophyllene (8.2%). Antibacterial activity determination was carried out according to the disc diffusion assay. Activity against Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212, at a minimal inhibitory concentration (MIC) of 170 microg/mL and 200 microg/mL, was found.