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Biomedical subjects

Z M Gu

Publications and source records attributed to Z M Gu.

At least 37 records · Page 2Linked to original sources
PubMed1994

Kneglomeratanol, kneglomeratanones A and B, and related bioactive compounds from Knema glomerata.

One new phenylalkyl phenol, kneglomeratanol [1], and two new acetophenones, kneglomeratanones A [2] and B [3], together with ten known compounds, 3-(12'-phenyldodecyl)-phenol [4], 3-(10'-phenyldecyl)-phenol [5], 5-pentadecylresorcinol [6], 5-(10'-phenyldecyl)-resorcinol [7], 5-(12'-phenyldodecyl)-resorcinol [8], 2,4-dihydroxy-6-(10'-phenyldecyl)-acetophenone [9], 2-hydroxy-6-(12'-phenyldodecyl)-benzoic acid [10], formononetin, biochanin A, and 8-O-methylretusin, have been isolated from the stem bark of Knema glomerata. Brine shrimp lethality was used for the activity-directed chromatographic fractionations. All of these compounds showed moderate but significant toxicities to three human tumor cell lines and inhibited the growth of crown gall tumors on discs of potato tubers.

Acetophenones↗
PubMed1994

Bioactive annonaceous acetogenins from the bark of Xylopia aromatica.

Bioactive Annonaceous acetogenins have been isolated from the EtOH extract of the bark of Xylopia aromatica by bioactivity-directed fractionation using lethality to brine shrimp. These acetogenins include xylopianin [1 , xylopiacin [2], and xylomaticin [3], which are three new mono-tetrahydrofuran ring type acetogenins, in addition to the known compounds, annomontacin, gigantetronenin, gigantetrocin A, and annonacin. Compounds 1 and 2 are unusual in having hydroxylation at C-8; 3 has the same functionalities as annonacin but with 37 carbons instead of 35 carbons. The structures were elucidated by spectral analysis of the parent compounds and/or simple chemical derivatives. These acetogenins showed cytotoxicities, comparable to adriamycin, against three human solid tumor cell lines.

Animals↗
PubMed1994

Two new bioactive monotetrahydrofuran Annonaceous acetogenins from the bark of Xylopia aromatica.

Xylopien [1] and xylomatenin [2], two new bioactive monotetrahydrofuran Annonaceous acetogenins, have been isolated from an EtOH extract of the bark of Xylopia aromatica, using bioactivity-directed fractionation employing lethality to brine shrimp. These new compounds each have a double bond in the hydrocarbon chain and have been identified as C-23, C-24 dehydro analogs of xylopiacin and xylomaticin. Their structures were elucidated by spectral analyses of the parent compounds and/or simple chemical derivatives. Their absolute stereochemistries have been established by 1H- and 2D nmr experiments utilizing the production of Mosher esters. These acetogenins showed cytotoxic potencies superior to adriamycin against three human solid tumor cell lines.

4-Butyrolactone↗
PubMed1993

30-, 31-, and 32-hydroxybullatacinones: bioactive terminally hydroxylated annonaceous acetogenins from Annona bullata.

From Annona bullata, three more pairs of new ketolactone Annonaceous acetogenins were isolated by bioactivity-directed isolation. They are hydroxylated adjacent bistetrahydrofuran (THF) acetogenins and are named (2,4-cis and trans)-32-hydroxybullatacinone (1 and 2), (2,4-cis and trans)-31-hydroxybullatacinone (3 and 4), and (2,4-cis and trans)-30-hydroxybullatacinone (5 and 6). The structures were elucidated by analysis of the 1H- and 13C-nmr spectra of 1-6 and their acetates and the ms of their tri-trimethylsilyl (TMSi) derivatives as compared with bullatacinone [7]. This is the first time that Annonaceous acetogenins with OH groups at successive positions near the end of the aliphatic chain have been reported. All of the new compounds showed potent activities in the brine shrimp lethality test and against human solid tumor cells in culture, with selectivities exhibited especially toward the colon cancer cell line (HT-29).

Animals↗
PubMed1992

Isolation and complete sequence of the purL gene encoding FGAM synthase II in Lactobacillus casei.

The purL gene from Lactobacillus casei, encoding phosphoribosylformylglycinamidine synthase II involved in the de novo synthesis of purines, was cloned and sequenced. The putative purL product of 741 amino acids (M(r) of 79,575) shows 25% and 53% identity to the homologous enzymes from Escherichia coli and Bacillus subtilis, respectively. In addition, partial sequences of two other pur genes (purQ and purF) and a possible third gene (purC) were obtained. All these genes are organized in an operon similar to that of B. subtilis. In contrast, the corresponding genes from E. coli and Salmonella typhimurium are scattered through the genome.

Amidophosphoribosyltransferase↗
PubMed1991

Comparison of anti-lipid peroxidative effects of the underground parts of Notopterygium incisum and N. forbesii in mice.

Intraperitoneal administration of CCl4 to mice led to significant increases of thiobarbituric acid-reactive substances (TBA-RS), free malondialdehyde (MDA), lipid conjugated dienes and fluorescent lipid peroxidation products in the liver. However, subchronic pretreatment with oral doses of the MeOH extract of either the underground part of Notopterygium incisum or that of N. forbesii appreciably suppressed the formation of CCl4-induced lipid peroxidation products. The suppressing potency was more remarkable in the former.

Animals↗
PubMed1991

Role of aorto-angioplasty in hypertension caused by Takayasu's arteritis.

Sixteen patients with Takayasu's arteritis and a long-stenotic segment of the descending thoracic aorta and/or proximal and middle portion of the abdominal aorta, with or without renal artery stenosis, were treated by percutaneous transluminal aorto-angioplasty (PTAA). These patients might be subdivided into three groups: A. with normal renal artery, B. with severe renal artery stenosis or occlusion without treatment or with failure of dilatation, and C. with renal artery stenosis but relieved by percutaneous transluminal renal angioplasty (PTRA). It was found that the hypertension may be caused by the suprarenal aortic stenosis itself. PTAA has an excellent effect to normalize the blood pressure in Group A. The elevated blood pressure may also be decreased in various extent in the patient with severe renal artery stenosis after PTAA, but not to normal. An additional PTRA or other renal vesel reconstruction procedure is necessary in this group. No recurrence of the aorta stenosis was found by non-invasive examinations or aortography during the long-term follow-up. PTAA may be considered as the first choice for the aortic stenosis caused by Takayasu's arteritis.

Adolescent↗
PubMed1990

Isolation of two new coumarin glycosides from Notopterygium forbesii and evaluation of a Chinese crude drug, qiang-huo, the underground parts of N. incisum and N. forbesii, by high-performance liquid chromatography.

From the ether extract of the underground part of Notopterygium forbesii, two new coumarin glycosides, bergaptol-O-beta-D-glucopyranoside and 6'-O-trans-feruloylnodakenin, were isolated along with known compounds including seven furanocoumarins, two dihydrofuranocoumarins, a sterol glucoside and two phenolic compounds. Analysis of their contents by high-performance liquid chromatography (HPLC) revealed that the underground part of N. forbesii contained large amounts of p-hydroxphenethyl anisate (0.7%), bergaptol glucoside (0.2%), nodakenin (2%) and 6'-O-trans-feruloylnodakenin (0.7%) and a lesser amount of notopterol (0.08%), while that of N. incisum contained a large amount of notopterol (1.2%) and less amounts of the others. The characteristic difference in chemical composition between the two species enabled us to identify the respective botanical sources of a Chinese crude drug, Qiang-huo derived from N. incisum and N. forbesii by HPLC.

Chromatography, High Pressure Liquid↗
PubMed1989

Isolation and complete sequence of the yeast isoleucyl-tRNA synthetase gene (ILS1).

The isoleucyl-tRNA synthetase gene (ILS1) from the yeast Saccharomyces cerevisiae was cloned and sequenced. This gene was initially cloned because it cross-hybridizated to what is now presumed to be the isoleucyl-tRNA synthetase gene (cupC) from the protozoan Tetrahymena thermophila. The ILS1 gene was determined to be 1,072 amino acids in length. A comparison with a recently published sequence of ILS1 from another laboratory (Englisch et al. 1987) was made and differences noted. Two promoter elements were detected, one for general amino acid control and one for constitutive transcription. A heat shock protein (hsp70) gene (probably SSA3) was found 237 bp upstream from the ILS1 translation start site. The ILS1 amino acid sequence was compared to isoleucyl-tRNA synthetases from other organisms, as well as to valyl-, leucyl- and methionyl-tRNA synthetases. Regions of conservation between these enzymes were found.

Amino Acid Sequence↗