Limonoids from the Seeds of a Hainan Mangrove, Xylocarpus granatum.
Ten new limonoids, hainangranatumins A-J (1-10), and 25 known compounds were isolated from seeds of a Chinese mangrove, Xylocarpus granatum, collected on Hainan Island. Hainangranatumins A-E (1-5) and I and J (9 and 10) are 9,10-seco-mexicanolides, whereas hainangranatumin F (6) is a limonoid possessing an 8α,30α-epoxy ring and a C1-C29 oxygen bridge. Hainangranatumin G (7) is a limonoid with a central pyridine ring, and hainangranatumin H (8) is a phragmalin 1,8,9-ortho ester. The relative configurations of hainangranatumins A and B were established by means of single-crystal X-ray diffraction analysis, and their absolute configurations were assigned on the basis of the specific rotation of the free acids obtained from alkaline hydrolysis. This is the first report of X-ray crystallographic structures of 9,10-seco-mexicanolides with a flexible C2-C30-C8 linkage. Hainangranatumins I and J (9 and 10), unusual 9,10-seco-mexicanolides with a C9-C30 linkage, are proposed to be artifacts derived from hainangranatumin C and xylomexicanin A, respectively.
Pan
Jian-Yu
JY
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, People's Republic of China.
Chen
Shi-Lin
SL
Li
Min-Yi
MY
Li
Jun
J
Yang
Mei-Hua
MH
Wu
Jun
J
D000818:Animals; D018360:Crystallography, X-Ray; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification*; D036701:Limonins / Q000737:chemistry / Q000302:isolation & purification*; D051379:Mice; D008968:Molecular Conformation; D015394:Molecular Structure; D043982:Rhizophoraceae / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry
D004365:Drugs, Chinese Herbal; D036701:Limonins; C554989:mexicanolide