TY - JOUR
T1 - Identification of a novel triterpenoid saponin from Pisum sativum as a specific inhibitor of the diguanylate cyclase of Acetobacter xylinum
AU - Ohana, Patricia
AU - Delmer, Deborah P.
AU - Carlson, Russell W.
AU - Glushka, John
AU - Azadi, Parastoo
AU - Bacic, Tony
AU - Benziman, Moshe
PY - 1998/2
Y1 - 1998/2
N2 - A specific and highly potent inhibitor of diguanylate cyclase, the key regulatory enzyme of the cellulose synthesizing apparatus in the bacterium Acetobacter xylinum, was isolated from extracts of etiolated pea shoots (Pisum sativum). The inhibitor has been purified by a multistep procedure, and sufficient amounts of highly purified compound (3-8 mg) for spectral analysis were obtained. The structure of this compound was established as 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl soyasapogenol B 22-O-a-D-glucopyranoside. The structure was elucidated on the basis of susceptibility to various enzymes, chemical and spectral methods, such as GC-MS, FAB-MS, and the following types of 2D-NMR: COSY, ROESY, TOCSEY, HMQC, HMBC analyses. An identical or a very similar compound with identical biological activity was also isolated from A. xylinum, strongly suggesting that at least certain aspects of cellulose synthesis in the bacteria and in higher plants may be regulated in a similar manner. The content of this saponin in etiolated plants was about 0.04 μmol (g fresh tissue)-1.
AB - A specific and highly potent inhibitor of diguanylate cyclase, the key regulatory enzyme of the cellulose synthesizing apparatus in the bacterium Acetobacter xylinum, was isolated from extracts of etiolated pea shoots (Pisum sativum). The inhibitor has been purified by a multistep procedure, and sufficient amounts of highly purified compound (3-8 mg) for spectral analysis were obtained. The structure of this compound was established as 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl soyasapogenol B 22-O-a-D-glucopyranoside. The structure was elucidated on the basis of susceptibility to various enzymes, chemical and spectral methods, such as GC-MS, FAB-MS, and the following types of 2D-NMR: COSY, ROESY, TOCSEY, HMQC, HMBC analyses. An identical or a very similar compound with identical biological activity was also isolated from A. xylinum, strongly suggesting that at least certain aspects of cellulose synthesis in the bacteria and in higher plants may be regulated in a similar manner. The content of this saponin in etiolated plants was about 0.04 μmol (g fresh tissue)-1.
KW - Acetobacter xylinun
KW - Diguanylate cyclase
KW - Inhibitor
KW - Pisum sativum
KW - Triterpenoid saponin
UR - http://www.scopus.com/inward/record.url?scp=0032005342&partnerID=8YFLogxK
U2 - 10.1093/oxfordjournals.pcp.a029351
DO - 10.1093/oxfordjournals.pcp.a029351
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C2 - 9559560
AN - SCOPUS:0032005342
SN - 0032-0781
VL - 39
SP - 144
EP - 152
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 2
ER -