Aplysinopsins - Marine Indole Alkaloids: Chemistry, Bioactivity and Ecological Significance

Aplysinopsins are tryptophan-derived marine natural products isolated from numerous genera of sponges and scleractinian corals, as well as from one sea anemone and one nudibranch. Aplysinopsins are widely distributed in the Pacific, Indonesia, Caribbean, and Mediterranean regions. Up to date, around 30 analogues occurring in Nature have been reported. Natural aplysinopsins differ in the bromination pattern of the indole ring, variation in the structure of the C ring, including the number and position of N-methylation, the presence and configuration of the C-8-C-1′ double bond, and the oxidation state of the 2-aminoimidazoline fragment. Aplysinopsins can also occur in the form of dimers. This review summarizes 30 years’ research on aplysinopsins. The origin, isolation sources, chemistry, bioactivity, and ecological functions of aplysinopsins are comprehensively reviewed

25. Isolation and Identification of Bacteria from Therapeutic Ball Pits Located in Hospital Settings

It is known that bacteria can be found on commercial ball pits. Due to ball pits moist, dark, warm environments, bacteria flourish, increasing risk of transmission. No study has been conducted on clinical therapeutic ball pits. These ball pits may be used constantly, yet no protocol exists on sanitation, or its frequency. Infrequent cleanings allow bacteria to reproduce to potentially infectious levels. Risk increases if the individual has lesions, abrasions, or is immunocompromised. An understanding in microbial communities of therapeutic ball pits and proper cleaning protocol was sought. A study was conducted using six clinical ball pits in Georgia. Sampling consisted of selecting random balls, swabbing five locations (four corners and center), and different strata (depths). Samples were plated on tryptic soy agar (TSA) plates, and incubated for twenty-four hours at 33 °C. Afterwards, microbial colonies were tallied. Colonies were identified using the Biolog GEN III Bacterial Identification System. Differences were found between clinics and the amount of colony forming units (CFU) from each sample. Clinic B had the least amount of CFU with 36% of balls having less than 3.0x101 CFU, and 7% with greater than 3.0x104 colonies. Clinic D had the largest CFU with 93% of balls having greater than 3.0x104 CFU. Potential opportunistic pathogens identified are Enterococcus faecalis, Acinetobacter lwoffii, Paoultella terrigena, Psychrobacter immobilis, Paenibacillus xylanilyficus, Klebsiella variicola, and Moraxella caprae. Balls with floor exposure had the most CFU; middle stratum balls had the least CFU; and balls with surface exposure had the second highest CFU

Finding and characterizing the complexes of drug like molecules with quadruplex DNA: combined use of an enhanced hydroxyl radical cleavage protocol and NMR.

Structural information on the complexes of drug like molecules with quadruplex DNAs can aid the development of therapeutics and research tools that selectively target specific quadruplex DNAs. Screening can identify candidate molecules that require additional evaluation. An enhanced hydroxyl radical cleavage protocol is demonstrated that can efficiently provide structural information on the complexes of the candidate molecules with quadruplex DNA. NMR methods have been used to offer additional structural information about the complexes as well as validate the results of the hydroxyl radical approach. This multi-step protocol has been demonstrated on complexes of the chair type quadruplex formed by the thrombin binding aptamer, d(GGTTGGTGTGGTTGG). The hydroxyl radical results indicate that NSC 176319, Cain's quinolinium that was found by screening, exhibits selective binding to the two TT loops. The NMR results are consistent with selective disruption of the hydrogen bonding between T4 and T13 as well as unstacking of these residues from the bottom quartet. Thus, the combination of screening, hydroxyl radical footprinting and NMR can find new molecules that selectively bind to quadruplex DNAs as well as provide structural information about their complexes

13. Isolation of Antimicrobial Compounds from Trischosporon spp

As antibiotic resistance in pathogenic microorganisms continues to be a world-wide health and safety concern, the demand for new and more advanced antibiotics has never been more pressing. The rate of antibiotic resistance among clinically relevant pathogens continues to increase while, at the same time, drug discovery, as it relates to antimicrobial compounds, has slowed to the point of being essentially stalled. As such, the discovery of novel antimicrobial compounds from previously unexploited sources could lead to the development of potential novel antimicrobial drugs that are in short supply. In this work, we have isolated a strain of Trichosporon beigelii which we found to produce multiple antimicrobial compounds. By testing crude extracts in disk diffusion assays against multiple drug resistant strains of bacteria, these compounds have shown signs of potential clinical viability and preliminary selectivity for pathogenic microorganisms such as Methicillin Resistant Staphylococcus aureus (MRSA) and Neisseria gonorrhoeae at concentrations of 1 mg/mL. These compounds have been further isolated and purified, following growth and production of the compounds in rich media, by using organic chemistry liquid-liquid extractions, analytical and preparative HPLC, and disk diffusion assays in an attempt to determine their molecular structures and usability. The further isolation and purification of these compounds could, potentially, yield compounds that could be developed as novel antibiotics

Representative cleavage results in the presence and absence of a drug like molecule.

<p>The cleavage results for the hydroxyl radical cleavage of the sample with the dT₁₁ tail on the 5′ end in the presence and absence of NSC 91881 are shown along with the results of a DMS cleavage. The changes in cleavage due to the presence of NSC 91881 are depicted for each band in the histogram on the right.</p

The 600 MHz spectra of TBA in the presence and absence of NSC 176319.

<p>The samples were at 288 K with the TBA at 1 mM. The integrated intensity of the G quartet region is the same in each spectrum. The dashed lines are to indicate which resonances change position as a function of NSC 176319 concentration.</p

Effects of NSC 176319 on the intensities of the imino resonances of T4 and T13.

<p>The ratio of the integrated intensity of the T4 and T13 resonances to that of the G quartets is plotted as a function of NSC 176319 concentration. The region of the 600</p

Depiction of the changes in cleavage induced by the four drug like molecules.

<p>The changes in cleavage of the residues are depicted using the chair type quadruplex structure of the DNA with blue indicating protection and red indicating enhanced cleavage. The changes for the 5′ and 3′ tail samples are both shown. Darker colors indicate a larger percentage change in the extent of cleavage.</p

The influence of pomegranate by-product and punicalagins on selected groups of human intestinal microbiota.

We have examined the gut bacterial metabolism of pomegranate by-product (POMx) and major pomegranate polyphenols, punicalagins, using pH-controlled, stirred, batch culture fermentation systems reflective of the distal region of the human large intestine. Incubation of POMx or punicalagins with faecal bacteria resulted in formation of the dibenzopyranone-type urolithins. The time course profile confirmed the tetrahydroxylated urolithin D as the first product of microbial transformation, followed by compounds with decreasing number of phenolic hydroxy groups: the trihydroxy analogue urolithin C and dihydroxylated urolithin A. POMx exposure enhanced the growth of total bacteria, Bifidobacterium spp. and Lactobacillus spp., without influencing the Clostridium coccoides–Eubacterium rectale group and the C. histolyticum group. In addition, POMx increased concentrations of short chain fatty acids (SCFA) viz. acetate, propionate and butyrate in the fermentation medium. Punicalagins did not affect the growth of bacteria or production of SCFA. The results suggest that POMx oligomers, composed of gallic acid, ellagic acid and glucose units, may account for the enhanced growth of probiotic bacteria