Biomedical subjects
Publications and source records attributed to T J Mabry.
In continuation of our research on Salvia triloba, acute and chronic antiinflammatory and ulcerogenic activities of chloroform, ethanol, butanol and water extracts were detected at 25 mg/kg p.o. The chloroform extract showed the highest antiinflammatory activity in both acute and chronic models, while the ulcerogenic effects of all tested extracts were found to be less than that of acetyl salicylic acid.
Three new acylated quercetin rhamnosides have been isolated from the leaves and stem of Calliandra haematocephala Hassk. (Fabaceae) and their structures were established as quercitrin 2''-O-caffeate (1), quercitrin 3''-O-gallate (2) and quercitrin 2'',3''-di-O-gallate (3). Also, 17 known compounds were identified as gallic acid (4), methyl gallate (5), caffeic acid (6), myricitrin (7), quercitrin (8), myricetin 3-O-beta-D-4C1-glucopyranoside (9), afzelin (10), isoquercitrin (11), myricetin 3-O-(6''-O-galloyl)-beta-D-glucopyranoside (12), myricitrin 2''-O-gallate (13), quercitrin 2''-O-gallate (14), afzelin 2''-O-gallate (15), myricitrin 3''-O-gallate (16), afzelin 3''-O-gallate (17), 1,2,3,4,6-penta-O-galloyl-beta-D-4C1-glucopyranose (18), myricitrin 2'',3''-di-O-gallate (19), quercetin 3-O-methyl ether (20), for the first time from the genus Calliandra except for 6. Compounds 7, 8, 13, 14, 16 and 19 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical, superoxide anion generation and DPPH radical in comparison with that of quercetin as a positive control in vitro. Compounds 7 and 8 exhibited lethal effect towards brine shrimp Artemia salina.
Two new flavonoids, 8-hydroxyisoscoparin (1) and luteolin 7-O-glucoside 4''-sulfate (2), along with eight known flavonoids, including luteolin 7-O-glucoside 2''-sulfate, were isolated and identified from Washingtonia filifera. All compounds were characterized by (1)H-NMR, (13)C-NMR, CI-MS, FABMS and UV. The antioxidant activities of various W. filifera extracts were determined.
Two new flavonoids, takakin 7-O-glucoside (1) and (2) bucegin 7-O-glucoside, and six other known compounds (3-8), takakin, isosctullarien, its 7-O-glucoside, takakin 8-O-glucoside, xanthotoxin and esculetin, were separated and identified from Glossostemon bruguieri. The new compounds were characterized using modern spectroscopic techniques, including UV spectroscopy, proton nuclear resonance (1HNMR), carbon thirteen nuclear resonance (13CNMR), homomolecular quantum coherance (HMQC), heteromolecular bonding connectivity (HMBC) and chemical ionization mass spectra (CI). The effect on rats urine volume of the plant powder, its ethanolic extract, (500 mg kg(-1)) along with four of the purified compounds (1,4-6), (100 mg kg(-1)) are described. Eight groups of albino rats (200-300 g body weight) (n=5 for each group) were used in the tests for a one-time treatment, and other seven groups (150-180 g body weight) (n=5 for each group) were tested using the same dose with repeated administration for 15 days. The rat sera were collected and used to determine liver and kidney functions based on alanine amino transferase (ALT) and aspartate amino transferase (AST) for both single and repeated administration. Levels of urea, creatinine and uric acid were determined for both sets of experiments. The toxic effects of both the powder and its alcoholic extract were also studied on mice to determine their LD50, both materials proved to be non-toxic up to 2500 mg kg(-1) body weight.
Plumbagin, isoshinanolone, epishinanolone, shinanolone, quercetin and kaempferol were isolated from the leaves of Nepenthes gracilis. Spectral data of shinanolone are presented.
A flavonoid trioside and its coumaryl ester together with seven known flavonoids and five phenolic acids were isolated from the leaves of Reseda muricata. Their structures were elucidated by spectroscopic methods including UV, FAB MS, 1H, 13C and 2D-NMR, DEPT, HMBC and HMQC experiments. The two compounds were identified as kaempferol 3-O-beta-D-glucopyranosyl-(1''' --> 2'')-O-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranoside and kaempferol 3-O-beta-D-glucopyranosyl-(1''' --> 2'')-O-alpha-L rhamnopyranoside 7-O-beta-D-(6''''-O-E-coumarylglucopyranoside), respectively.
Twelve hydrocarbons, four sterols, three triterpenes, nineteen fatty acids, two phenolic acids, and five flavonoids have been detected and identified in Salvia triloba. Among the isolated flavonoids, 8-methoxygenistein 7-O-alpha-L-rhamnoside 4'-O-beta-D-glucoside (1), is reported for the first time.
Reinvestigation of the MeOH-CH(2)Cl(2) extract of the aerial parts of Cleome amblyocarpa led to isolation of a new dammarane triterpenoid, 15alpha-acetoxycleomblynol A, whose structure was determined to be 11alpha,15alpha-diacetoxybrachycarpon-22(23)-ene (1) by NMR data interpretation and X-ray analysis.
The elucidation by NMR and chemical methods of the unique structure of betanidin, the aglycon of the red-violet beet pigment betanin, forty years ago at the University of Zürich, Switzerland, was the beginning of my plant chemistry research program. Many of the same chemical and spectral techniques developed in Zürich have been used at The University of Texas at Austin for the structure analysis of members of many other classes of natural products including especially flavonoids, terpenoids, and alkaloids. Investigations at UT-Austin have concerned many topics such as biochemical and molecular systematics, biosynthetic pathways, structure-activity relationships, and the medicinal importance of natural products and included studies of antiviral proteins in the genus Phytolacca and neurotoxic nonprotein amino acids from cycads and other sources. Following the betalain story and an account of the early development of my UT-Austin biochemical systematic program, the Phytolacca and neurotoxin investigations are discussed herein.
Re-investigation of the aerial parts of Iva frutescens resulted in the isolation of three sesquiterpenes, two of which are new natural products, and their structures were established by spectral data.
Nonprotein amino acids from nine species of cycad seeds were analyzed as N-ethoxycarbonyl ethyl ester (ECEE) derivatives by positive chemical-ionization gas chromatography-mass spectrometry. Based on the retention times and mass spectrometry analyses, 12 nonprotein amino acids were identified in these seeds. In addition to the excitatory and putative neurotoxin beta-N-methylamino-L-alanine (BMAA), the known neurotoxin beta-N-oxalylamino-L-alanine (BOAA) was detected from the seeds of Macrozamia moorei and M. communis, and delta-N-oxalyl-ornithine was obtained from the Cycas revoluta seeds. A novel nonprotein amino acid named cycasindene, previously reported from C. revoluta, was also found in the seeds of members of the C. angulata and C. rumphii complex. Eight additional known nonprotein amino acids were also identified. This is the first report of the neurotoxin BOAA from cycad seeds.
Two nonprotein amino acids, cycasindene and cycasthioamide, along with eight known nonprotein amino acids, were isolated from the seeds of Cycas revoluta Thunb. The structures of cycasindene and cycasthioamide were elucidated as 3-[3'-amino-indenyl-2]-alanine (1) and N-[glycinyl-alaninyl-11-thio]-5-one-pipecolic acid (2) by chemical and spectral methods.
A new clerodane diterpenoid and two new long chain esters of trans- and cis-coumaric acid, in addition to known triterpenoids and one known clerodane diterpenoid, have been isolated and characterized from Baccharis myrsinites. The structures were determined by spectroscopic techniques.
Our chemical studies on Cycas circinalis seeds from Guam has provided two new nonprotein amino acids, N-(3'-one-5'-methyl)-hexylalanine and leucine betaine. N-methylisoleucine, previously reported as a component of naturally occurring peptides, has been isolated as a free amino acid from the seeds of Phaseolus vulgaris (pinto bean), together with S-methylcysteine, pipecolic acid and a dipeptide, gamma-glutamyl-leucine.
Two new compounds, 2,6-bis-O-digalloyl-3-O-galloylglucose and 2-O-trigalloyl-1,3,4,6-tetrakis-O-galloylglucose, along with four known gallotannins, were isolated and identified from the leaves of Haematoxylon campechianum. In addition, four known flavonoid and three simple phenolic compounds were also detected.
A new glucose derivative (1) and 2-C-methyl-D-erythritol (2) were isolated from the leaves of Ferula sinaica. The two structures were elucidated by highfield NMR spectroscopy, and that of 1 was confirmed by X-ray diffraction analysis.
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A new cycloartane triterpenoid glycoside has been isolated from the rhizomes of Cimicifuge foetida L. The spectroscopic characteristics of the new compound are different from previously described cycloartane triterpenoids because of the loss of the 24-isopropyl group as well as the presence of a 11 beta-OH group. Based on spectroscopic evidence, including a series of 2D-NMR analyses, the structure of the new triterpene is assigned as 24-des-isopropyl-7-ene-23-one-9,19; 16,24-dicycloart-3 beta,11 beta,16 alpha,24 alpha-tetraol 3-O-beta-D-xylopryanoside, named here as neocimiside. The structure of the aglycone of neocimiside was confirmed by X-ray analysis.