Aplysamine 6, an Alkaloidal Inhibitor of Isoprenylcysteine Carboxyl Methyltransferase from the Sponge <i>Pseudoceratina</i> sp.

Buchanan, Malcolm S.; Carroll, Anthony Richard; Fechner, Gregory Allen; Boyle, Anthony; Simpson, Moana; Addepalli, Rama; Avery, Vicky M.; Hooper, John N. A.; Cheung, Tony; Chen, Huwei; Quinn, Ronald J.

doi:10.1021/np0706623

Cited by 48 publications

(23 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among the broad spectrum of α‐oximinotyrosine derived natural products isolated from marine sponges, in particular 11‐deoxyfistularin‐3 ( 1 ),4a purealidin P ( 6 ),4b and Q ( 7 )4d are cytotoxic against the MCF‐7 breast cancer cell line (LD 50 = 17 μg/L),4a murine lymphoma K1210 (IC 50 2.8 and 0.95 μg mL –1 , respectively),4b and human epidermal carcinoma KB (nasopharynx) (IC 50 7.6 and 1.2 μg mL –1 , respectively)4d cell lines (Figure 1). The other members from the same family are also widely known for their diverse pharmacological activities including antiviral,5 antimicrobial,6 anti‐HIV,7 antifungal,8 antifouling,9 Na + /K + ATPase inhibition,10 HDAC inhibition,11 histamine H 3 antagonism,12 mycothiol S ‐conjugate amidase inhibition,13 and isoprenylcysteine carboxymethyl transferase (Icmt) inhibition 14. The distinguishable molecular diversity arises due to several prominent structural features including; (a) brominated spiroisoxazoline core that contains a cyclohexadiene, a bromo epoxy ketone, or a bromohydrin moiety, (b) the R or S absolute stereochemistry of the spiro stereogenic center of spiroisoxazoline amide core, (c) the presence of a diverse range of amine and diamine spacers attached to the spiroisoxazolines.…”

Section: Introductionmentioning

confidence: 99%

Doubling the Capacity of Lithium Manganese Oxide Spinel by a Flexible Skinny Graphitic Layer

et al. 2014

View full text Add to dashboard Cite

By coating nanoparticular lithium manganese oxide (LMO) spinel with a few layers of graphitic basal planes, the capacity of the material reached up to 220 mA h g−1 at a cutoff voltage of 2.5 V. The graphitic layers 1) provided a facile electron‐transfer highway without hindering ion access and, more interestingly, 2) stabilized the structural distortion at the 3 V region reaction. The gain was won by a simple method in which microsized LMO was ball‐milled in the presence of graphite with high energy. Vibratory ball milling pulverized the LMO into the nanoscale, exfoliated graphite of less than 10 layers and combined them together with an extremely intimate contact. Ab initio calculations show that the intrinsically very low electrical conductivity of the tetragonal phase of the LMO is responsible for the poor electrochemical performance in the 3 V region and could be overcome by the graphitic skin strategy proposed.

show abstract

Section: Introductionmentioning

confidence: 99%

Doubling the Capacity of Lithium Manganese Oxide Spinel by a Flexible Skinny Graphitic Layer

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Most recently we have investigated by using the scale‐out strategy with MACOS to produce multigram quantities of benzo‐fused sultams 3. Here we are furthering the development of this platform to multi‐step transformations for the production of tyramine‐based natural products entirely by flow4 (see Scheme for target structures) 5–8. We are attracted to the members of this family of natural products for their inherent biological activity,9–13 but additionally they can themselves serve as templates for the diversity‐oriented synthesis of analogues.…”

Section: Methodsmentioning

confidence: 99%

The Development of a General Strategy for the Synthesis of Tyramine‐Based Natural Products by Using Continuous Flow Techniques

Achanta

Liautard

Paugh

et al. 2010

Chemistry A European J

View full text Add to dashboard Cite

A silicon‐containing water‐borne polyurethane (PU) polymer with hydroxyl side groups was synthesized that was stable in basic conditions and also capable of reacting with a reactive dye to form a covalently bonded dye molecule. The silicon‐containing anionic water‐borne PU prepolymer was synthesized from H12‐4,4′‐diphenylmethane diisocyanate (H12‐MDI), polytetramethylene glycol, polydimethylsiloxane (PDMS), 2,2′‐bis(hydroxymethyl), propionic acid (anionic centers), and triethyleneamine using the prepolymer mixing method. Water was then added to emulsify and disperse the resin to form an anionic water‐borne PU prepolymer. N‐(2‐Hydroxyethyl ethylene diamine) (HEDA) was used to extend the prepolymer to form a water‐borne PU polymer with a side chain of hydroxyl groups, which can further react with the reactive dye to form a dyed PU. The reactive dye of chlorosulfuric acid esters of sulfatoethyl sulfones can react with the water‐borne PU polymer. Behaviors of alkali resistance and dyeing properties were observed. In consideration of thermal properties, the dye‐grafted PU polymers exhibited lower glass‐transition temperatures for soft segments and hard segments than those without dye. Concerning mechanical properties, it was found that the modulus and the strength of the dyed PU polymers decreased with grafting of the dye molecule, but elongation at break was increased. The alkali resistance increased with PDMS content. For dye‐uptake properties, the percentage of dye grafting was over 90%. Also, the dye‐grafted PU exhibited a lower percentage of dye migration than that of polymers with ethylene diamine instead of HEDA as a chain extender, and showed greater colorfastness to light. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2045–2052, 2003

show abstract

“…Among the widely studied genera of this order is Pseudoceratina sp. From this order different bromotyrosine derivatives were isolated including pseudoceramines A–D and spermatinamine [13], aplysamine 6 [14], ceratinadins A–C [15], as well as 11,19-dideoxyfistularin-3, 11-deoxyfistularin-3 and dibromoverongiaquinol [16]. The wide diversity of the separated bromotyrosine derivatives has encouraged us to subject Pseudoceratina sp., collected from the Green Island on the east cost of Taiwan, to an intensive chemical investigation which led to the isolation of (1′ R ,5′ S ,6′ S )-2-(3′,5′-dibromo-1′,6′-dihydroxy-4′-oxocyclohex-2′-enyl) acetonitrile (DT) (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Towards the Small and the Beautiful: A Small Dibromotyrosine Derivative from Pseudoceratina sp. Sponge Exhibits Potent Apoptotic Effect through Targeting IKK/NFκB Signaling Pathway

Chen

El-Shazly

et al. 2013

Marine Drugs

View full text Add to dashboard Cite

A dibromotyrosine derivative, (1′R,5′S,6′S)-2-(3′,5′-dibromo-1′,6′-dihydroxy-4′-oxocyclohex-2′-enyl) acetonitrile (DT), was isolated from the sponge Pseudoceratina sp., and was found to exhibit a significant cytotoxic activity against leukemia K562 cells. Despite the large number of the isolated bromotyrosine derivatives, studies focusing on their biological mechanism of action are scarce. In the current study we designed a set of experiments to reveal the underlying mechanism of DT cytotoxic activity against K562 cells. First, the results of MTT cytotoxic and the annexin V-FITC/PI apoptotic assays, indicated that the DT cytotoxic activity is mediated through induction of apoptosis. This effect was also supported by caspases-3 and -9 activation as well as PARP cleavage. DT induced generation of reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential (MMP) as indicated by flow cytometric assay. The involvement of ROS generation in the apoptotic activity of DT was further corroborated by the pretreatment of K562 cells with N-acetyl-cysteine (NAC), a ROS scavenger, which prevented apoptosis and the disruption of MMP induced by DT. Results of cell-free system assay suggested that DT can act as a topoisomerase II catalytic inhibitor, unlike the clinical anticancer drug, etoposide, which acts as a topoisomerase poison. Additionally, we found that DT treatment can block IKK/NFκB pathway and activate PI3K/Akt pathway. These findings suggest that the cytotoxic effect of DT is associated with mitochondrial dysfunction-dependent apoptosis which is mediated through oxidative stress. Therefore, DT represents an interesting reference point for the development of new cytotoxic agent targeting IKK/NFκB pathway.

show abstract

Aplysamine 6, an Alkaloidal Inhibitor of Isoprenylcysteine Carboxyl Methyltransferase from the Sponge Pseudoceratina sp.

Cited by 48 publications

References 7 publications

Doubling the Capacity of Lithium Manganese Oxide Spinel by a Flexible Skinny Graphitic Layer

Doubling the Capacity of Lithium Manganese Oxide Spinel by a Flexible Skinny Graphitic Layer

The Development of a General Strategy for the Synthesis of Tyramine‐Based Natural Products by Using Continuous Flow Techniques

Towards the Small and the Beautiful: A Small Dibromotyrosine Derivative from Pseudoceratina sp. Sponge Exhibits Potent Apoptotic Effect through Targeting IKK/NFκB Signaling Pathway

Contact Info

Product

Resources

About