A new eoumarino-lignoid cleomiseosin B has been isolated from the seeds of Cleome viscosa and its structure has been elucidated as I based on chemical and spectroscopic evidence which, in turn, has brought on the revision of the structure of eleomiscoein A as IV.We recently made a phytochemieal investigation on the seeds of Cleome viscosa LinnE (syn.2. icoeandra Linn6, Capparidaceae) used as a folklore medicine in India and reported the isolation of a coumarino-lignoid, eleomiscosin A for vhich the structure I was advanced. 1A thorough search for chemical constituents from the seed extract has now led to the ieolation of a new congener which is named as cleomiecosin 8.The present paper describes the structure determination of cleomiscosin B and the concurrent structure reviaion of eleomiseosin A. Cleomiscoain 8, m.p. 274', C H 0 (MS mle 386.1014,Mt), and eleomiseosin A showed striking 20 18 8 resemblance in spectral properties, indicating a close structural similarity between the two molecules.Thus the 13c NMR spectrum of cleomiseosin B disclosed the presence of seven aliphatic carbons (CH -0 x 2, -CH2-0 x 1, >CH-0 x 2, -CH=CH-x I), twelve aromatic carbons (CH x 4, C x 2, 3 C-0 x 6 ) and one carbonyl carbon like its congener, cleomiscosin A (Table I).The oxygen functions were first examined.Cleomiscosin B was found to be phenolic in nature (IR bend at 3510 c m l , positive phoephomolybdic acid test) and gave the con-phenolic monomethyl ether (11).m.p. 212-213'.C21HZOHB (MS de 400, M+).since the ether (11) still exhibited an I R band at 3530 cm-' (hydroxyl), cleomiscosin B was aeetylated to fvrnish the diaeetate (III), m.p. 174', C24H22010 (Ms 470, M ' ) , whieh showed no IR band due to hydroxyl.Cleomiscosin B was thus proved to bear one phenolic and one alcoholic hydroryl grouping.Further, cleomiscosin B displayed a UV maximum at 328 nm with humps at 285 end 230 om, showed IR bands at 1720 and 1610 cm-' and disclosed two ' 8 NMR 1" doublete et S 6.21 and 7.51 (J 10 HZ), indicating that the same coumarin rn~iety is present in cleomiscosin B as in cleomiecoein A. The ' H NMR spectrum also indicated the presence of two methoxyl groups (6 3.71 and 3.83) in cleomiseosin B. Thus six out of eight oxygen atoms were accounted for and the remaining two oxygens were to
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Ray et al. (1982) studied this question.