ChemInform Abstract: Two New Lobane Derivatives from the Soft Coral Lobophytum pauciflorum of the Havelock Island of the Indian Ocean.

Abstract

Two New Lobane Derivatives from the Soft Coral Lobophytum pauciflorum of the Havelock Island of the Indian Ocean. --(ANJANEYULU, A. S. R.; RAO, G. V.; RAJU, K. V. S.; MURTHY, M. V. R. K.; Indian J.

Anti-Inflammatory Lobane and Prenyleudesmane Diterpenoids from the Soft Coral Lobophytum varium

“…Further separation using a series of normal phase (NP) and reversed phase (RP) silica yielded five new diterpenoids lobovarols A–E ( 1 – 5 , Figure 1 ) and seven known lobane diterpenoids ( 6 – 12 , Figure 2 ). The chemical identities of the known compounds ( 6 – 12 ) were determined by comparison of their infrared (IR), mass spectrum (MS), and nuclear magnetic resonance (NMR) spectroscopic data with the published data and were found to be lobatriene ( 6 ) [ 32 , 33 ], lobatrienolide ( 7 ) [ 34 ], isofuscol ( 8 ) [ 24 ], fuscol ( 9 ) [ 35 ], 13,15-epoxyloba-8,10,16-trien-18-ol ( 10 ) [ 36 ], 17,18-epoxyloba-8,10,13(15)-trien-16-ol ( 11 ) [ 13 , 14 ], and (1 R ,2 R ,4 S ,17 R )-loba-8,10,13(15)-trien-17,18-diol ( 12 ) [ 12 ], respectively.…”

“…Furthermore, a ring-junctured methyl (δ C 16.5, CH 3 ; δH 0.99, 3H, s) and a methine (δ C 52.1, CH; δ H 1.94, br dd, J = 9.2, 6.0 Hz) groups exhibited 3 J CH heteronuclear multiple bond correlations (HMBC) to each other and designated a β-elemene ( 13 ) ring system [ 12 , 13 , 37 ] in the molecule. These NMR signals are also characteristic for the lobane-type diterpenoids [ 11 , 12 , 13 , 14 , 25 ]. The presence of a trisubstituted epoxide (δ C 64.2, C, and 59.1, CH; δ H 3.49, dd, J = 2.0, 2.0 Hz), a dimethyl hydroxymethine (δ C 71.1, C, 26.5, CH 3 , and 24.0, CH 3 ; δ H 1.22 and 1.13, each 3H s), an oxymethine (δ C 68.3, CH; δ H 3.45, dd, J = 11.2, 3.0 Hz) and a dioxy-methine (δ C 89.5, CH; δ H 5.30, s) were also confirmed in the side chain of the six-membered ring.…”

“…Marine organisms have been well recognized as an important source of natural products with diverse chemical structures and wide array of bioactivities, including the anti-inflammatory activities [ 1 , 2 , 3 ]. Soft corals belonging to the genus Lobophytum (Alcyoniidae) are considered to be a rich source of diterpenoids [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] and steroids [ 17 , 18 , 19 , 20 , 21 , 22 ], of which some exerted cytotoxic [ 4 , 5 , 6 , 7 , 8 , 18 , 21 , 23 ], antibacterial [ 4 , 8 , 10 , 11 ], antiviral [ 15 ], anti-acetylcholinesterase [ 9 ], and anti-inflammatory activities [ 6 , 8 , 10 , 15 , 16 , 19 ]. The terpenoid metabolites of cembrane-derived [ 4 , 5 , 6 , 7 , 8 , 9 , 15 ...…”

New Lobane and Cembrane Diterpenes from Two Comorian Soft Corals

“…Only one other publication mentions the coexistence of lobane and cembrane diterpenoids in a soft coral: fuscol and isofuscol were isolated with 11, 12-epoxycembra-1, 3, 7-triene, decaryol and 3, 4-epoxycembra-7, 11-dien-15-ol from Lobophytum microlobulatum [ 22 ]. The co-occurrence of lobane with sesquiterpenes (Δ 9(15) -africanene [ 5 , 23 ], 15-nor-13-keto-β-elemene [ 5 , 21 , 24 ]) or with steroids [ 5 , 6 , 21 , 25 , 26 ] has also been reported. Until now, lobanes have been exclusively isolated from the Gorgonian species Eunicea fusca [ 2 ] and from the soft corals of the genera Lobophytum [ 3 – 6 ] and Sinularia [ 7 – 9 , 27 ].…”

Synthesis and characterization of novel fatty acid analogs of cholesterol: In vitro antimicrobial activity

“…It was discussed that cholesterol derivatives could have antimicrobial activity [24]. In view of the significance of long-chain FA as potential pharmacophores; we report here the synthesis and spectral studies of new cholesterol analogs containing C11 and C18 FA along with their in vitro evaluation against a panel of Gram-positive, Gram-negative strains of bacteria and some strains of fungus.…”