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Jianjun Zhang

Publications and source records attributed to Jianjun Zhang.

41 records · Page 3Linked to original sources
PubMed2002

Synthesis of a mannose heptasaccharide of the pathogenic yeast, Candida glabrata IFO 0622 strain.

An effective synthesis of the mannose heptasaccharide existing in the pathogenic yeast, Candida glabrata IFO 0622 strain was achieved via TMSOTf-promoted condensation of a tetrasaccharide donor 13 with a trisaccharide acceptor 16, followed by deprotection. The tetrasaccharide 13 was constructed by coupling of 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl-(1-->3)-2,4,6-tri-O-acetyl-alpha-D-mannopyranosyl trichloroacetimidate (7) with allyl 3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranoside (10), followed by deallylation and trichloroacetimadation. The trisaccharide 16 was obtained by coupling of 6-O-acetyl-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate with 10, and subsequent 6-O-deacetylation. The disaccharide 7 was prepared through coupling of perbenzoylated mannosyl trichloroacetimidate with 4,6-O-benzylidene-1,2-O-ethylidene-beta-D-mannopyranose, then simultaneous debenzylidenation and deethylidenation, and subsequent acetylation, selective 1-O-deacetylation, and trichloroacetimidation. The disaccharide 10 was obtained by self-condensation of 3,4,6-tri-O-benzoyl-1,2-O-allyloxyethylidene-beta-D-mannopyranose, followed by selective 2-O-deacetylation.

Candida glabrata↗
PubMed2002

[Fine deletion mapping on chromosome 8p21 - 8p22 in adenocarcinoma of lung].

OBJECTIVE: To determine the common deletion region of loss of heterozygosity (LOH) on chromosome 8p21-8p22 in adenocarcinomas of lung, and facilitate identification of candidate tumor suppressor genes associated with adenocarcinoma of lung. METHODS: PCR and microsatellite analysis were used to examine the LOH frequency of 17 microsatellite loci at the 8p21-8p22 in the samples resected from 32 patients with lung adenocarcinoma and adenosquamous carcinoma. The relationship of LOH for each marker to pathological grade and that to clinical stage are investigated. RESULTS: Thirty-one out of the 32 (96.67%) samples showed allelic loss in at least one of the 17 markers. The most frequent LOH loci were mainly located in the three regions: D8S254-261, D8S1827-1731, and D8S1135 loci. Among them, the LOH frequency of D8S261 locus was related to the stage of tumor (P < 0.05). CONCLUSION: An interval of common deletion on chromosome 8p22, encompassing D8S254-261, D8S1827-1731 and D8S1135, might harbor candidate tumor suppressor gene(s) associated with pathogenesis of adenocarcinoma of lung.

Adenocarcinoma↗
PubMed2002

Synthesis of an xylosylated rhamnose pentasaccharide, the repeating unit of the O-chain polysaccharide of the lipopolysaccharide of Xanthomonas campestris pv. begoniae GSPB 525.

A xylosylated rhamnose pentasaccharide, alpha-L-Rhap-(1-->3)-[beta-L-Xylp-(1-->2)-]-alpha-L-Rhap-(1-->3)-[beta-L-Xylp-(1-->4)]-L-Rhap, the repeating unit of the O-chain polysaccharide (OPS) of the lipopolysaccharides of Xanthomonas campestris pv. begoniae GSPB 525 was synthesized by a highly regio- and stereoselective way. Thus coupling of 1,2-O-ethylidene-beta-L-rhamnopyranose (1) with 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate (2) to give (1-->3)-linked disaccharide (3), subsequent benzoylation, deethylidenation, acetylation, 1-O-deacetylation, and trichloroacetimidation afforded the disaccharide donor 11. Condensation of 11 with 1 yielded 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->3)-2-O-acetyl-4-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->3)-1,2-O-ethylidene-beta-L-rhamnopyranose (12), and selective deacetylation of 12 yielded the trisaccharide diol acceptor 15. Coupling of 15 with 2,3,4-tri-O-benzoyl-alpha-L-xylopyranosyl trichloroacetimidate (16), followed by deprotection, gave the target pentasaccharide 19.

Carbohydrate Sequence↗
PubMed2002

[Loss of heterozygosity fine mapping of chromosome 17p13 in transitional cell carcinoma of human urinary bladder].

OBJECTIVE: To determine the frequency and common deletion region of allelic losses on chromosome 17p13 in transitional cell carcinoma (TCC) of human urinary bladder so as to provide clues for isolation of candidate tumor suppressor genes associated with TCC of urinary bladder. METHODS: Loss of heterozygosity (LOH) analysis was made on 44 samples of surgically resected primary TCC by using 13 microsatellite markers to map the regions frequently deleted on chromosome 17p13. The relationship between the LOH in each locus and pathological grade and stage was analyzed. RESULTS: Out of the 44 samples, 35 (79.5%) showed allelic loss in at least one of the 17p13 loci. The highest frequency of LOH (41.4%, 12/29) was at D17S513 in 17p13.2, the second highest frequency of LOH (40.5%, 17/42) was at D17S1308 in 17p13.3, and the lowest (14.3%, 4/28) was at D17S261 in 17p13.1. The most frequent LOH loci were mainly located in three regions: D17S695-D17S1308 in 17p13.3, D17S1533-D17S831 in 17p13.2, and TP53 in 17p13.1. Among them only the LOH frequency of TP53 locus was positively correlated to the grade (chi(2) = 5.104, P < 0.05) and stage (chi(2) = 5.382, P < 0.05) of TCC of unrinary bladder. CONCLUSION: In 17p13 region, except for TP53 gene, still exist two candidate tumor suppressor genes located in D17S695-D17S1308 and D17S1533-D17S831 involved in the carcinogenesis of TCC of urinary bladder. LOH of TP53 locus may be one of the later events in TCC, and LOH in 17p13.3 and 17p13.2 may be the early events of TCC of uninary bladder.

Carcinoma, Transitional Cell↗