(±)-Caryopterisines A and B, dimeric monoterpene alkaloids with unprecedented 6/5/5/5/6 pentacyclic rings scaffold from Caryopteris glutinosa

Exploring the Biomedical Potential of Terpenoid Alkaloids: Sources, Structures, and Activities

“…They are two novel dimers with a 6/5/5/5/6 pentacyclic system. In addition, they can be biosynthesized by oxerine dehydration or oxygenation and subsequent Diels-Alder reactions [22].…”

“…Among them, (5S*,7R*)-7-Ethoxy-6, 7-dihydro-7-methyl-5H-cyclopenta[c]pyridin-5-ol ( 8) is a monoterpene alkaloid with a cyclopenta[c]pyridine framework [24]. (5aR*,6S*,10S*,11R*,11aR*)-10,11a-Dimethyl-6,7,9,10,11,11a-hexahydro-5H-6,11-epoxycyclopenta [6,7]azuleno [1,2-c]pyridin-5,8(5aH)dione (21) and (5aR*,6S*,7aR*,8S*,11aR*)-10-Hydroxy-7a,11a-dimethyl-5a,6,7,7a,8,11ahexahydro-5H-6,8-epoxycyclopenta [6,7]azuleno [1,2-c] pyridin-5-one (22) could be formed by fusion of the cyclopenta[c]pyridine and 4-Demethyliridoid, and (5R*,5aR*,10bS*,11R*)-5-Hydroxy-10b,11-dimethyl-5,5a,10b,11-tetrahydro-6H-5,11-methanopyrido [3 ′ ,4 ′ :3,4]cyclopenta [1,2-g]isoquinolin-6-one (23) and (6S*,6aR*,11R*,11aS*)-6a-Hydroxy-11,11a-dimethyl-6,6a,11, 11a-tetrahydro-5H-6,11-methanopyrido [3 ′ ,4 ′ :4,5]cyclopenta [1,2-h]isoquinolin-5-one (24) are dimerization products of two cyclopenta[c]pyridine [24]. Caryopteris glutinosa whole plant [22] (5aR*,6S*,10S*,11R*,11aR*)-10,11a-Dimethyl-6,7,9,10,11,11a-hexahydro-5H-6,11epoxycyclopenta [6,7]azuleno [1,2-c]pyridin-5,8(5aH)-dione.…”

Sources, Transformations, Syntheses, and Bioactivities of Monoterpene Pyridine Alkaloids and Cyclopenta[c]pyridine Derivatives

“…Subsequently, (±)-caryopterisines B ( 27 ) and A ( 28 ) with a 6/5/5/5/6 pentacyclic ring system were identified as racemates from Caryopteris glutinosa Rehder (Lamiaceae) [ 18 ]. Additionally, each of them underwent chiral HPLC examination, and computed ECD or X-ray diffraction analysis was used to determine their absolute configurations.…”

“…In cell-based estrogen biosynthesis experiments, it was discovered that both 27 and 28 moderately reduced the manufacture of estrogen E2. Additionally, they moderately decreased kynurenine production by inhibiting indoleamine 2,3-dioxygenase [ 18 ]. It is possible for compound 28 to only slightly suppress interleukin-1 β release [ 18 ].…”

“…Additionally, they moderately decreased kynurenine production by inhibiting indoleamine 2,3-dioxygenase [ 18 ]. It is possible for compound 28 to only slightly suppress interleukin-1 β release [ 18 ].…”