Dinah Espineli | Cavite State University - Silang Campus (original) (raw)

Papers by Dinah Espineli

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives (1, 3a and 3b), chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol (7). The structures of 1 and 3a-7 were identified by NMR spectroscopy

6-hydroxy-24-ethylcholest-4,22-dien-3-one ( 3b ), and another mixture of (24 R)-24-ethylcholest-... more 6-hydroxy-24-ethylcholest-4,22-dien-3-one ( 3b ), and another mixture of (24 R)-24-ethylcholest-4-en-3one ( 4a ) and (24 S)-24-ethylcholest-4,22-dien-3-one ( 4b ). Cardenolide 1 exhibited extreme toxicity to A549, HCT 116 and Hep G2 with IC 50 values of 0.003 g/mL, 0.013 g/mL, and 0.018 g/mL, respectively, while sample 3 exhibited an IC 50 of 1.35 g/mL, 4.46 g/mL, and 3.83 g/mL, respectively.

Pharmaceutical Chemistry Journal, Nov 30, 2014

The triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely a mixt... more The triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio, and a mixture of 3b-olean-18-en-3-yl palmitate (7), 3b-urs-12-en-3-yl palmitate (8) and 3b-olean-12-en-3-yl palmitate (9) in a 4:1:2 ratio from the bark; germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) from the leaves; and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited an IC50 value of 8.0 mg•mL−1 against this cell line, while 6 exhibited an IC50 value of 29.6 mg•mL−1. The other compounds tested (3−5, 7−10) were inactive against the HCT 116 cell line. The mixture of 1 and 2, and 6, were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The...

Chemistry of Natural Compounds, 2013

The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tr... more The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tree, afforded four new chromomoric acid derivatives ( 1, 2, 3a, and 3b). Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial testing was carried out on 1- 3 against a panel of bacteria and fungi.

Pharmaceutical Chemistry Journal, 2014

Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture... more Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio and a mixture of 3β-olean-18-en-3-yl palmitate (7), 3β-urs-12-en-3-yl palmitate (8) and 3β-olean-12-en-3-yl palmitate (9) in a 4 : 1 : 2 ratio (isolated from the bark), as well as germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) (from the leaves), and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited IC 50 = 8.0 µg • mL‫-‬ 1 against this cell line, while 6 exhibited an IC50 value of 29.6 µg • mL‫-‬ 1. The other compounds tested (3-5, 7-10) were inactive against the HCT 116 cell line. The mixture of 1 and 2 and compound 6 were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The mixture of 1 and 2 and compound 6 exhibited IC 50 values of 6.0 and 35.6 µg • mL‫-‬ 1 , respectively. The cytotoxicity for the mixture of 1 and 2 may be attributed to betulinic acid (1), a known cytotoxic compound. Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio and a mixture of 3β-olean-18-en-3-yl palmitate (7), 3β-urs-12-en-3-yl palmitate (8) and 3β-olean-12-en-3-yl palmitate (9) in a 4 : 1 : 2 ratio (isolated from the bark), as well as germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) (from the leaves), and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited IC 50 = 8.0 µg • mL‫-‬ 1 against this cell line, while 6 exhibited an IC 50 value of 29.6 µg • mL‫-‬ 1. The other compounds tested (3-5, 7-10) were inactive against the HCT 116 cell line. The mixture of 1 and 2 and compound 6 were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The mixture of 1 and 2 and compound 6 exhibited IC 50 values of 6.0 and 35.6 µg • mL‫-‬ 1 , respectively. The cytotoxicity for the mixture of 1 and 2 may be attributed to betulinic acid (1), a known cytotoxic compound.

Chinese Journal of Natural Medicines, 2014

To investigate the chemical constituents of Cinnamomum cebuense, an endemic and critically endang... more To investigate the chemical constituents of Cinnamomum cebuense, an endemic and critically endangered tree found only in Cebu, Philippines. The compounds were isolated by silica gel chromatography. The structures of the isolates were elucidated by NMR spectroscopy. The dichloromethane (DCM) extract of the bark of C. cebuense afforded a new monoterpene natural product 1 and a new sesquiterpene 2, along with the known compounds, 4-hydroxy-3-methoxycinnamaldehyde (3), 4-allyl-2-methoxyphenol (4), α-terpineol (5) and humulene (6). The DCM extract of the leaves of C. cebuense yielded 6, β-caryophyllene (7), squalene (8), and a mixture of α-amyrin (9), β-amyrin (10) and bauerenol (11). The structures of 1-7 were elucidated by extensive 1D and 2D NMR spectroscopy, while the structures of 8-11 were identified by comparison of their (13)C NMR data with those reported in the literature. The bark of C. cebuense afforded monoterpenes, sesquiterpenes and phenolics, while the leaves yielded sesquiterpenes and triterpenes.

AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds we... more AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS:

AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds we... more AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS:

Chemistry of Natural Compounds, Mar 1, 2014

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A mixture of bauerenol (1a), α-amyrin (1b) and β-amyrin (1c) in a 3:1:2 ratioobtained from the di... more A mixture of bauerenol (1a), α-amyrin (1b) and β-amyrin (1c) in a 3:1:2 ratioobtained from the dichloromethane extract of air-dried leaves of Ardisia squamulosa was tested on duck chorioallantoic membrane (CAM). The mixture of 1a-1c exhibited inhibition of vascularization and formation of ghost vessels on CAMswith 100% embryo survivability at the end of a 9-day treatment period. A possible angio-suppression by inhibition of branch point formation, reduction of inter-capillary distance as well as reduced vascular density in CAMs administered with 1a-1care also reported. Immunohistochemistry reveals high degree of von Willebrand factor expression and the absence of epithelial membrane antigen. This suggests that the observed angio-suppression was due to the effect of von Willebrand factor in regulation of other angiogenesis modulators. Consolacion Y. Ragasa et al J. Chem. Pharm. Res., 2013, 5(10):230-239 ______________________________________________________________________________ 231

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives , chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol . The structures of 1 and 3a-7 were identified by NMR spectroscopy.

The dichloromethane extract of the aerial parts of Emilia sonchifolia afforded a mixture of tarax... more The dichloromethane extract of the aerial parts of Emilia sonchifolia afforded a mixture of taraxasteryl acetate (1a) and lupeol acetate (1b) in a 1:0.3 ratio. Their structures were elucidated by extensive 1D and 2D NMR spectroscopy.

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives (1, 3a and 3b), chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol (7). The structures of 1 and 3a-7 were identified by NMR spectroscopy.

A mixture of bauerenol (1a), -amyrin (1b) and b-amyrin (1c) in a 3:1:2 ratio obtained from the d... more A mixture of bauerenol (1a), -amyrin (1b) and b-amyrin (1c) in a 3:1:2 ratio obtained from the dichloromethane extract of air-dried leaves of Ardisia squamulosa was tested on duck chorioallantoic membrane (CAM). The mixture of 1a-1c exhibited inhibition of vascularization and formation of ghost vessels on CAMs with 100% embryo survivability at the end of a 9-day treatment period. A possible angio-suppression by inhibition of branch point formation, reduction of inter-capillary distance as well as reduced vascular density in CAMs administered with 1a-1c are also reported. Immunohistochemistry reveals high degree of von Willebrand factor expression and the absence of epithelial membrane antigen. This suggests that the observed angio-suppression was due to the effect of von Willebrand factor in regulation of other angiogenesis modulators.

Chinese Journal of Natural Medicines, Jul 20, 2012

""[ABSTRACT] AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The... more ""[ABSTRACT] AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by
silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS: The dichloromethane extract of the air-dried leaves of Glinus oppositifolius afforded a new triterpene, oppositifolone (1), spinasterol (2), squalene (3) and lutein (4). The structure of 1 was elucidated by NMR spectroscopy, while 2−4 were identified by comparison of their 13C NMR data with those reported in the literature. CONCLUSION: A new triterpene was isolated from G. oppositifolius.""

Pharmacognosy Research, 2015

To isolate the secondary metabolites from the dichloromethane (DCM) extracts of Glinus oppositifo... more To isolate the secondary metabolites from the dichloromethane (DCM) extracts of Glinus oppositifolius; to test for the cytotoxicity of a new triterpene, oppositifolone (1); and to test for the hypoglycemic, analgesic, and antimicrobial potentials of 1, DCM and aqueous leaf extracts of G. oppositifolius. Methods: The compounds were isolated by silica gel chromatography and identified by nuclear magnetic resonance spectroscopy. The cytotoxicity potential of 1 was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Triterpene 1, DCM, and aqueous leaf extracts were tested for hypoglycemic potential using the oral glucose tolerance test; analgesic potential using the tail-flick assay, and antimicrobial potential using the disc diffusion method. Results: The DCM extracts of G. oppositifolius afforded 1, squalene, spinasterol, oleanolic acid, phytol, and lutein from the leaves; squalene and spergulagenin A from the stems; and spinasterol from the roots. Triterpene 1 was cytotoxic against human colon carcinoma 116 with an IC 50 value of 28.7 but did not exhibit cytotoxicity against A549. The aqueous leaf extract at 200 mg/kg body weight (BW) exhibited hypoglycemic activity with a pronounced % blood glucose reduction of 70.76% ±17.4% within 0.5 h after introduction. The DCM leaf extract showed a lower % blood glucose reduction of 18.52% ±13.5% at 200 mg/kg BW within 1.5 h after introduction, while 1 did not exhibit hypoglycemic activity. The samples did not exhibit analgesic property and were inactive against multiple drug resistant bacterial pathogens. Conclusion: The compounds responsible for the hypoglycemic activity of G. oppositifolius which are fast acting (0.5 h) are found in the aqueous leaf extract.

Pharmaceutical Chemistry Journal, 2014

The dichloromethane extract of Cinnamomum cebuense afforded α-terpineol (1), 4-allyl-2methoxyphen... more The dichloromethane extract of Cinnamomum cebuense afforded α-terpineol (1), 4-allyl-2methoxyphenol or eugenol (2), humulene (3), 4-hydroxy-3-methoxycinnamaldehyde (4) and a monoterpene (5) which were evaluated for cytotoxicity against colon carcinoma (HCT 116). Compound 4 showed moderate cytotoxicity against this cell line with an IC 50 value of 18.8004 µg/mL, while 3 and 5 exhibited slight cytotoxicity. Compounds 3 -5 were further tested for cytotoxicity against non-small cell lung adenocarcinoma (A549) and non-cancer Chinese hamster ovary cells (AA8). Sesquiterpene 3 exhibited moderate cytotoxicity against A549 with an IC 50 value of 23.1964 µg/mL, 4 indicated slight cytotoxicity, while 5 was non-toxic against this cell line. Compound 4 showed moderate cytotoxicity against AA8 with an IC 50 value of 20.4837 µg/mL, while 3 and 5 exhibited slight cytotoxicity. Compounds 1, 2 and 3 were active against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis and fungi Candida albicans and Trichophyton mentagrophytes, but were found inactive against Aspergillus niger. Sesquiterpene 3 was the most active against E. coli, P. aeruginosa, S. aureus, C. albicans and T. mentagrophytes, while 1 exhibited the highest activity against B. subtilis, even surpassing the activity of the standard antibiotic chloramphenicol.

ChemInform, 2012

A New Triterpene from Atalantia retusa Merr -[isolation, structure elucidation, cytotoxicity and ... more A New Triterpene from Atalantia retusa Merr -[isolation, structure elucidation, cytotoxicity and antimicrobial properties of the new triterpene retusenol (I) and some known compounds, e.g. friedelin and dischidiol]. -(RAGASA*, C. Y.; ESPINELI, D. L.; MANDIA, E. H.; RAGA, D. D.; DON, M.-J.; SHEN, C.-C.; Z. Naturforsch., B: Chem. Sci. 67 (2012) 5, 426-432, http://dx.

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives (1, 3a and 3b), chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol (7). The structures of 1 and 3a-7 were identified by NMR spectroscopy

6-hydroxy-24-ethylcholest-4,22-dien-3-one ( 3b ), and another mixture of (24 R)-24-ethylcholest-... more 6-hydroxy-24-ethylcholest-4,22-dien-3-one ( 3b ), and another mixture of (24 R)-24-ethylcholest-4-en-3one ( 4a ) and (24 S)-24-ethylcholest-4,22-dien-3-one ( 4b ). Cardenolide 1 exhibited extreme toxicity to A549, HCT 116 and Hep G2 with IC 50 values of 0.003 g/mL, 0.013 g/mL, and 0.018 g/mL, respectively, while sample 3 exhibited an IC 50 of 1.35 g/mL, 4.46 g/mL, and 3.83 g/mL, respectively.

Pharmaceutical Chemistry Journal, Nov 30, 2014

The triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely a mixt... more The triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio, and a mixture of 3b-olean-18-en-3-yl palmitate (7), 3b-urs-12-en-3-yl palmitate (8) and 3b-olean-12-en-3-yl palmitate (9) in a 4:1:2 ratio from the bark; germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) from the leaves; and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited an IC50 value of 8.0 mg•mL−1 against this cell line, while 6 exhibited an IC50 value of 29.6 mg•mL−1. The other compounds tested (3−5, 7−10) were inactive against the HCT 116 cell line. The mixture of 1 and 2, and 6, were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The...

Chemistry of Natural Compounds, 2013

The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tr... more The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tree, afforded four new chromomoric acid derivatives ( 1, 2, 3a, and 3b). Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial testing was carried out on 1- 3 against a panel of bacteria and fungi.

Pharmaceutical Chemistry Journal, 2014

Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture... more Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio and a mixture of 3β-olean-18-en-3-yl palmitate (7), 3β-urs-12-en-3-yl palmitate (8) and 3β-olean-12-en-3-yl palmitate (9) in a 4 : 1 : 2 ratio (isolated from the bark), as well as germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) (from the leaves), and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited IC 50 = 8.0 µg • mL‫-‬ 1 against this cell line, while 6 exhibited an IC50 value of 29.6 µg • mL‫-‬ 1. The other compounds tested (3-5, 7-10) were inactive against the HCT 116 cell line. The mixture of 1 and 2 and compound 6 were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The mixture of 1 and 2 and compound 6 exhibited IC 50 values of 6.0 and 35.6 µg • mL‫-‬ 1 , respectively. The cytotoxicity for the mixture of 1 and 2 may be attributed to betulinic acid (1), a known cytotoxic compound. Triterpenes isolated from the dichloromethane extract of Barringtonia asiatica, namely, a mixture of betulinic acid (1) and 22-O-tigloylcamelliagenin A (2) in a 1 : 2 ratio and a mixture of 3β-olean-18-en-3-yl palmitate (7), 3β-urs-12-en-3-yl palmitate (8) and 3β-olean-12-en-3-yl palmitate (9) in a 4 : 1 : 2 ratio (isolated from the bark), as well as germanicol caffeoyl ester (3), germanicol trans-coumaroyl ester (4), germanicol cis-coumaroyl ester (5) and germanicol (6) (from the leaves), and a phenolic compound, verimol K (10) from the flowers, were assessed for cytotoxicity against a human cancer cell line, colon carcinoma (HCT 116), using the MTT assay. The mixture of 1 and 2 exhibited IC 50 = 8.0 µg • mL‫-‬ 1 against this cell line, while 6 exhibited an IC 50 value of 29.6 µg • mL‫-‬ 1. The other compounds tested (3-5, 7-10) were inactive against the HCT 116 cell line. The mixture of 1 and 2 and compound 6 were further tested for cytotoxicity against the non-small cell lung adenocarcinoma (A549) cell line. The mixture of 1 and 2 and compound 6 exhibited IC 50 values of 6.0 and 35.6 µg • mL‫-‬ 1 , respectively. The cytotoxicity for the mixture of 1 and 2 may be attributed to betulinic acid (1), a known cytotoxic compound.

Chinese Journal of Natural Medicines, 2014

To investigate the chemical constituents of Cinnamomum cebuense, an endemic and critically endang... more To investigate the chemical constituents of Cinnamomum cebuense, an endemic and critically endangered tree found only in Cebu, Philippines. The compounds were isolated by silica gel chromatography. The structures of the isolates were elucidated by NMR spectroscopy. The dichloromethane (DCM) extract of the bark of C. cebuense afforded a new monoterpene natural product 1 and a new sesquiterpene 2, along with the known compounds, 4-hydroxy-3-methoxycinnamaldehyde (3), 4-allyl-2-methoxyphenol (4), α-terpineol (5) and humulene (6). The DCM extract of the leaves of C. cebuense yielded 6, β-caryophyllene (7), squalene (8), and a mixture of α-amyrin (9), β-amyrin (10) and bauerenol (11). The structures of 1-7 were elucidated by extensive 1D and 2D NMR spectroscopy, while the structures of 8-11 were identified by comparison of their (13)C NMR data with those reported in the literature. The bark of C. cebuense afforded monoterpenes, sesquiterpenes and phenolics, while the leaves yielded sesquiterpenes and triterpenes.

AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds we... more AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS:

AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds we... more AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS:

Chemistry of Natural Compounds, Mar 1, 2014

The user has requested enhancement of the downloaded file.

A mixture of bauerenol (1a), α-amyrin (1b) and β-amyrin (1c) in a 3:1:2 ratioobtained from the di... more A mixture of bauerenol (1a), α-amyrin (1b) and β-amyrin (1c) in a 3:1:2 ratioobtained from the dichloromethane extract of air-dried leaves of Ardisia squamulosa was tested on duck chorioallantoic membrane (CAM). The mixture of 1a-1c exhibited inhibition of vascularization and formation of ghost vessels on CAMswith 100% embryo survivability at the end of a 9-day treatment period. A possible angio-suppression by inhibition of branch point formation, reduction of inter-capillary distance as well as reduced vascular density in CAMs administered with 1a-1care also reported. Immunohistochemistry reveals high degree of von Willebrand factor expression and the absence of epithelial membrane antigen. This suggests that the observed angio-suppression was due to the effect of von Willebrand factor in regulation of other angiogenesis modulators. Consolacion Y. Ragasa et al J. Chem. Pharm. Res., 2013, 5(10):230-239 ______________________________________________________________________________ 231

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives , chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol . The structures of 1 and 3a-7 were identified by NMR spectroscopy.

The dichloromethane extract of the aerial parts of Emilia sonchifolia afforded a mixture of tarax... more The dichloromethane extract of the aerial parts of Emilia sonchifolia afforded a mixture of taraxasteryl acetate (1a) and lupeol acetate (1b) in a 1:0.3 ratio. Their structures were elucidated by extensive 1D and 2D NMR spectroscopy.

Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus aff... more Chemical investigation of the dichloromethane extract of the leaves of Sphaeranthus africanus afforded carvotanacetone derivatives (1, 3a and 3b), chrysosplenol D (4), squalene (5), spinasterol (6), and stigmasterol (7). The structures of 1 and 3a-7 were identified by NMR spectroscopy.

A mixture of bauerenol (1a), -amyrin (1b) and b-amyrin (1c) in a 3:1:2 ratio obtained from the d... more A mixture of bauerenol (1a), -amyrin (1b) and b-amyrin (1c) in a 3:1:2 ratio obtained from the dichloromethane extract of air-dried leaves of Ardisia squamulosa was tested on duck chorioallantoic membrane (CAM). The mixture of 1a-1c exhibited inhibition of vascularization and formation of ghost vessels on CAMs with 100% embryo survivability at the end of a 9-day treatment period. A possible angio-suppression by inhibition of branch point formation, reduction of inter-capillary distance as well as reduced vascular density in CAMs administered with 1a-1c are also reported. Immunohistochemistry reveals high degree of von Willebrand factor expression and the absence of epithelial membrane antigen. This suggests that the observed angio-suppression was due to the effect of von Willebrand factor in regulation of other angiogenesis modulators.

Chinese Journal of Natural Medicines, Jul 20, 2012

""[ABSTRACT] AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The... more ""[ABSTRACT] AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by
silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS: The dichloromethane extract of the air-dried leaves of Glinus oppositifolius afforded a new triterpene, oppositifolone (1), spinasterol (2), squalene (3) and lutein (4). The structure of 1 was elucidated by NMR spectroscopy, while 2−4 were identified by comparison of their 13C NMR data with those reported in the literature. CONCLUSION: A new triterpene was isolated from G. oppositifolius.""

Pharmacognosy Research, 2015

To isolate the secondary metabolites from the dichloromethane (DCM) extracts of Glinus oppositifo... more To isolate the secondary metabolites from the dichloromethane (DCM) extracts of Glinus oppositifolius; to test for the cytotoxicity of a new triterpene, oppositifolone (1); and to test for the hypoglycemic, analgesic, and antimicrobial potentials of 1, DCM and aqueous leaf extracts of G. oppositifolius. Methods: The compounds were isolated by silica gel chromatography and identified by nuclear magnetic resonance spectroscopy. The cytotoxicity potential of 1 was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Triterpene 1, DCM, and aqueous leaf extracts were tested for hypoglycemic potential using the oral glucose tolerance test; analgesic potential using the tail-flick assay, and antimicrobial potential using the disc diffusion method. Results: The DCM extracts of G. oppositifolius afforded 1, squalene, spinasterol, oleanolic acid, phytol, and lutein from the leaves; squalene and spergulagenin A from the stems; and spinasterol from the roots. Triterpene 1 was cytotoxic against human colon carcinoma 116 with an IC 50 value of 28.7 but did not exhibit cytotoxicity against A549. The aqueous leaf extract at 200 mg/kg body weight (BW) exhibited hypoglycemic activity with a pronounced % blood glucose reduction of 70.76% ±17.4% within 0.5 h after introduction. The DCM leaf extract showed a lower % blood glucose reduction of 18.52% ±13.5% at 200 mg/kg BW within 1.5 h after introduction, while 1 did not exhibit hypoglycemic activity. The samples did not exhibit analgesic property and were inactive against multiple drug resistant bacterial pathogens. Conclusion: The compounds responsible for the hypoglycemic activity of G. oppositifolius which are fast acting (0.5 h) are found in the aqueous leaf extract.

Pharmaceutical Chemistry Journal, 2014

The dichloromethane extract of Cinnamomum cebuense afforded α-terpineol (1), 4-allyl-2methoxyphen... more The dichloromethane extract of Cinnamomum cebuense afforded α-terpineol (1), 4-allyl-2methoxyphenol or eugenol (2), humulene (3), 4-hydroxy-3-methoxycinnamaldehyde (4) and a monoterpene (5) which were evaluated for cytotoxicity against colon carcinoma (HCT 116). Compound 4 showed moderate cytotoxicity against this cell line with an IC 50 value of 18.8004 µg/mL, while 3 and 5 exhibited slight cytotoxicity. Compounds 3 -5 were further tested for cytotoxicity against non-small cell lung adenocarcinoma (A549) and non-cancer Chinese hamster ovary cells (AA8). Sesquiterpene 3 exhibited moderate cytotoxicity against A549 with an IC 50 value of 23.1964 µg/mL, 4 indicated slight cytotoxicity, while 5 was non-toxic against this cell line. Compound 4 showed moderate cytotoxicity against AA8 with an IC 50 value of 20.4837 µg/mL, while 3 and 5 exhibited slight cytotoxicity. Compounds 1, 2 and 3 were active against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis and fungi Candida albicans and Trichophyton mentagrophytes, but were found inactive against Aspergillus niger. Sesquiterpene 3 was the most active against E. coli, P. aeruginosa, S. aureus, C. albicans and T. mentagrophytes, while 1 exhibited the highest activity against B. subtilis, even surpassing the activity of the standard antibiotic chloramphenicol.

ChemInform, 2012

A New Triterpene from Atalantia retusa Merr -[isolation, structure elucidation, cytotoxicity and ... more A New Triterpene from Atalantia retusa Merr -[isolation, structure elucidation, cytotoxicity and antimicrobial properties of the new triterpene retusenol (I) and some known compounds, e.g. friedelin and dischidiol]. -(RAGASA*, C. Y.; ESPINELI, D. L.; MANDIA, E. H.; RAGA, D. D.; DON, M.-J.; SHEN, C.-C.; Z. Naturforsch., B: Chem. Sci. 67 (2012) 5, 426-432, http://dx.