Monanchosterols A and B, Bioactive Bicyclo[4.3.1]steroids from a Korean Sponge Monanchora sp.

Abstract

Chemical investigation of a Korean marine sponge, Monanchora sp., led to the isolation of three new steroids (1-3). Compounds 1 and 2, designated as monanchosterols A and B, respectively, represent the first examples of steroids possessing the bicyclo[4.3.1] A/B ring system from a natural source. Compounds 1-3 were investigated for their anti-inflammatory activity by evaluating their inhibitory effects on the mRNA expression of IL-6, TNF-α, and COX-2 in the LPS-stimulated murine RAW264.7 macrophage cells. Compounds 2 and 3 exhibited significant inhibitory effects on the mRNA expression of IL-6 without notable cytotoxicity to the cells in a dose-dependent manner.

Marine natural products

“…680 While 1085 was toxic to RAW264.7 cells (IC 50 65 mM), both 1086 and 1087 were not, but instead were immunomodulatory inhibiting mRNA expression of IL-6 by $70% at 10 mM even though monanchosterols A and B only differ by a single acetylation. 681 A nortriterpenoid-saponin 1088, 675 686 while the absolute conguration of euryspongin A 1102 (Euryspongia sp.) was also determined using chiroptical techniques.…”

Antioxidant drimane‐type sesquiterpenoid from muricid gastropodChicoreus ramosusattenuates pro‐inflammatory 5‐lipoxygenase and carbolytic enzymes

“…Greater electronic property of the studied terpenoid was deduced to be directly proportional to the antioxidant properties, which implied that the site of the hydroxyl groups and electron withdrawing keto functionalities in the compound could result in the effective quenching of the free radicals. The molecular electronic parameter, such as tPSA, relevant to the chemical potentials (Wang et al, ) recorded higher values in the isolated compound ( tPSA 37.3) over than that exhibited by the commercial antioxidant standard α ‐tocopherol (tPSA 29.46), and showed no significant difference with the anti‐inflammatory standard ibuprofen (tPSA 37.30). Thus, the roles of hydrophobic and electronic descriptors in ascertaining the functional properties of the studied compound Ramosane were emphasized.…”

Marine Pharmacology in 2014–2015: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis, Antiviral, and Anthelmintic Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…nov. strain MT1.1, isolated from a Mariana Trench sediment at a depth of 10,898 m [189]; a novel sesquiterpene dysifragilone A (173), isolated from the South China Sea sponge Dysidea fragilis [190]; a new xenicane 4α-hydroxypachylactone (174), isolated from a Chinese brown alga Dictyota plectens [191]; a polyketide comaparvin (175), isolated from the Taiwanese marine crinoid Comanthus bennetti [192]; two novel eunicellin-type diterpenoids hirsutalins N and S (176, 177) and a new tocopherol-derived metabolite hirsutocospiro A (178), isolated from the Taiwanese soft coral Cladiella hirsuta [193][194][195]; a new cembranoid isosinulaflexiolide K (179), isolated from cultured Taiwanese soft corals Sinularia sandensis and Sinularia flexibilis [196]; a novel 9,11-secogorgosteroid klyflaccisteroid F (180), isolated from the Taiwaneses soft coral Klyxum flaccidum [197]; new eunicellin-type diterpenoids krempfielins N (181), Q (182), and R (183), isolated from a Taiwanese soft coral Cladiella krempfi [198,199]; a methylfarnesylquinone (184), isolated from the Taiwanese marine brown alga Homeostrichus formosana [200]; a novel steroid monanchosterol B (185), isolated from the Korean sponge Monanchora sp. [201]; a oxygenated steroid derivative (186), isolated from the Vietnamese starfish Protoreaster nodosus [202]; a new spirobisnaphthalene rhytidenone C (187), isolated from an extract of a cultured fungal endophyte Rhytidhysteron sp. AS21B isolated from a Thailandese mangrove area [203]; a known terpenoid sarcocrassocolide E (188), isolated from a Taiwanese soft coral Sarcophyton crassocaule [204]; a new cembrane diterpenoid sinulacembranolide A (189), isolated from the Taiwanese soft coral Sinularia gaweli [205]; a new eudesmane-type sesquiterpene thomimarine B (190), isolated from the fungus Penicillium thomii KMM 4667 isolated from the Japanese sea grass Zostera marina [206]; and a novel diterpenoid tortuosene A (191), isolated from the Taiwanese soft coral Sarcophyton tortuosum …”

“…As shown in Table 2 and Figure 2, in 2014-2015, the preclinical marine nervous system pharmacology of compounds (196)(197)(198)(199)(200)(201)(202)(203)(204)(205)(206)(207)(208)(209)(210)(211) described several mechanism of action: at the nicotinic acetylcholine receptor and potassium channels, with conopeptides, and in models of antinociception and neuroprotection.…”

“…Three studies extended the pharmacology of conopeptides (201)(202)(203). Wang and colleagues discovered a novel α-conotoxin Mr1.7 (201) in the venom of the marine snail Conus marmoreus that inhibited α3β2, α9α10, and α6/α3β2β3 nACHR subtypes (IC 50 = 53.1, 185.7, and 284.2 nM, respectively), noting that the PE residues at the N-terminal sequence of Mr1.7 were "important for modulating activity and selectivity" [217].…”