Squamocin, an annonaceous acetogenin, enhances naphthalene degradation mediated by Bacillus atrophaeus CN4 / Squamocin, una acetogenina annonácea, estimula la degradación de naftaleno mediada por Bacillus atrophaeus CN4

Squamocin belongs to a group of compounds called annonaceous acetogenins. They are secondary products of Annonaceae metabolism and can be isolated from Annona cherimolia seeds. This paper deals with the stimulation of biofilm formation of Bacillus atrophaeus CN4 by employing low squamocin concentrations to increase naphthalene degradation. Bacillus atrophaeus CN4, isolated from contaminated soil, has the ability to degrade naphthalene as the only source of carbon and energy. In the absence of additional carbon sources, the strain removed 69% of the initial concentration of naphthalene (approx. 0.2 mmol/l) in the first 12 h of incubation. The addition of squamocin in LB medium stimulated Bacillus atrophaeus CN4 biofilm formation and enhanced naphthalene removal. Squamocin (2.5 pg/ml) does not affect planktonic growth and therefore, the observed increases are solely due to the stimulation of biofilm formation.

Squamocin pertenece a un grupo de compuestos llamados acetogeninas annonáceas (ACG). Las ACG son productos secundarios del metabolismo de plantas de la familia Annonaceae y se pueden aislar a partir de semillas de Annona cherimola. Este artículo trata de la estimulación de la formación de biofilm de Bacillus atrophaeus CN4 mediante el empleo de bajas concentraciones de squamocin para optimizar la degradación de naftaleno. B. atrophaeus CN4, aislado de suelo contaminado, tiene la capacidad de emplear naftaleno como única fuente de carbono y energía. En ausencia de fuentes de carbono adicionales, la cepa degradó el 69% de la concentración inicial de naftaleno (aprox. 0,2 mmol/l) en las primeras 12h de incubación. La adición de squamocin en medio LB estimula la formación de biofilm y la remoción naftaleno de B. atrophaeus CN4. Squamocin (2,5 µg/ml) no afecta al crecimiento planctónico y, por lo tanto, los incrementos observados se deben únicamente a la estimulación de la formación de biofilm.

Two new annonaceous acetogenins from seeds of Annona squamosa / 中草药

Objective: To study the chemical constituents from the seeds of Annona squamosa. Methods: Modern methods such as silica gel column and preparation liquid phase were used to isolate and purify the components of annonaceous acetogenins from the seeds of A. squamosa. The structures of the compounds were identified by their physico-chemical properties, UV, NMR and mass spectrometry data. Results: Ten adjacent bistetrahydrofuran annonaceous acetogenins were isolated from CO2 supercritical extract of the seeds from A. squamosa. They were 3-((13R)-13-((2R,2'R,5R,5'R)-5'-((1S)-1,5-dihydroxynonyl) octahydro-[2,2'-bifuran]-5-yl)-13-hydroxytridecyl)-5-methylfuran-2 (5H)-one (1), 3-((2R,9R)-2,9-dihydroxy-9-((2R,2'R,5R,5'R)-5'-((S)-1-hydroxypentadecyl) octahydro-[2,2'-bifuran]-5-yl) nonyl)-5-methylfuran-2 (5H)-one (2), 6-hydroxy-desacetyl-uvaricin (3), 6-hydroxy-4-deoxy-squamotacin (4), bullanin (5), 10-hydroxy-asimicin (6), folianin A (7), annosquacin I (8), annosquacin C (9), and squamocin I (10). Conclusion: Compounds 1 and 2 are two new compounds named as 28-hydroxy-squamocin L (1) and 4-hydroxy-squamocin Y (2), respectively. Compounds 3-7 are isolated from A. squamosa for the first time.