This thesis describes the phytochemical investigations on the chemical constituents of two indigenous medicinal plants of Pakistan and is, therefore, divided into two parts entitled:
Part A Phytochemical studies on Murraya paniculata (Linn.) Jack.
Part B Phytochemical studies on Ipomoea hederacea Jacq
The introduction of Part A describes the biosynthesis of coumarins. It also includes the review of the earlier contributions made in the chemistry and pharmacology of Murraya paniculata. Altogether nine coumarins are reported from the aerial parts of this plant. Out of these three coumarins namely, murrmeranzin (130), 1 ',2'-0-isopropylidene murrangatin (131) and murralonginal (132) are found to be new whereas one coumarin, pranferin (133) is being reported for the first time from the plant.
The introduction of Part B provides a brief review of biosynthesis of triterpenoids and ecdysteroids. It also provides a brief account of physiology and pharmacology of Ipomoea hederacea. With the exception of a few chemical constituents earlier reported not much work has been done on this plant. In the present study, the isolation and structural elucidation of ten compounds from the seeds of Ipomoea hederacea are discussed. These compounds include five ecdysteroids, two steroidal glycosides, one triterpene and two aromatic acids. Out of these three ecdysteroids namely, hederasterone A (168), hederasterone A-20,22. monoacetonide (169) and hederasterone B (170) are new. The compound 170 showed enzyme inhibition activity against butyrylcholinesterase, while 176 and 177 exhibited lypoxygenase inhibition activity. The structures of new compounds were established through spectroscopic methods including UV, IR, MS, IH-NMR, 13C-NMR, 2D-NMR experiments (J-Resolved, COSY-45°, NOESY, HMQC, HMBC, BB and DEPT) and chemical transformations. The known compounds have been identified through comparison of their physical and spectral data with those reported for the corresponding compounds in literature.
PART A (a) New compounds isolated from Murraya paniculata 1) Murrmeranzin (130) 7,7" -Dimethoxy,8,8" -( 1 ',3'" -dihydroxy-3' -methyl-3' -butenyl-3'" -methylbutyl)-2-0-2˝-bi-2H-1-benzopyran-2-one. 2) 1',2'-0-isopropylidene murrangatinn (131) 8-(1',2'-0-isopropylidene-3'-methy-butenly1)-7-methoxy-2H-1-benzopyran-2-one 3) Murralonginal (132) 8-(1'2'-0-isopropylidene-3'-methyl-3' butenyl)-7-methoxy-2H-1-benzopyran-2-one (b) Compound reported for the first time from Murraya paniculata 1) Pranferin (133)
Part B (a) New compounds isolated from ipomoea headeracea 1) Hederasterone A (168) ( 2B, 3a, 5B, 14a, 20R, 22R-Hexahydroxycholest-7,9(11)-dien-6-one) 2) Hederasterone A-20, 22-monoacetonide (169) (2B, 3a, 5B, 14a-Tetrahydroxycholest-7,9 (11)-diene-6-one-20,22-acetonide) 3) Hederasterone B (170) (2B, 3a, 11a, 14a, 20R, 22R,-Heptahydroxycholest-7-en-6-one) (b) Compouds reported for the first time from ipomoea hederacea 2) 20-Hydroxyecdysone-20,22-monoacetonide (171) 3) 20-Hydroxyecdysone (172) 4) Stigmasterol 3-0-B-D-glucoside (173) 5) B-Sitosterol-3-O-B-D-glucoside (174) 6) Oleanolic acid (175) 7) Caffeic acid (176) 8) Ethylcaffeate (177)