Ochraceopetalin, a Mixed-Biogenetic Salt of Polyketide and Amino Acid Origins from a Marine-Derived Aspergillus ochraceopetaliformis Fungus

Ochraceopetalin (1), a mixed-biogenetic salt compound and its component 2 were isolated from the culture broths of a marine-derived fungus, Aspergillus ochraceopetaliformis. Based on combined spectroscopic and chemical analyses, the structure of 1 was determined to be a sulfonated diphenylether-aminol-amino acid ester guanidinium salt of an unprecedented structural class, while 2 was determined to be the corresponding sulfonated diphenylether. Ochraceopetaguanidine (3), the other guanidine-bearing aminol amino acid ester component, was also prepared and structurally elucidated. Compound 1 exhibited significant cytotoxicity against K562 and A549 cells.

Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

An Amino Acid Ester of Menthol Elicits Defense Responses in Plants

Terpenoids, including menthol, exhibit potent abilities as plant defense potentiators in agriculture and horticulture. In the current study, we developed new terpene derivatives that consisted of menthol and various amino acids and that were expected to act as powerful plant defense potentiators. We used 6 amino acids possessing low-reactive sidechains to synthesize an array of amino acid ester of menthol (ment-aa) compounds. Transcript levels of two defense genes (pathogenesis-related 1 [PR1] and trypsin inhibitor [TI]) were evaluated in leaves of soybean plants 24 h after application of aquatic solution of menthol or menthol-aa, and revealed that the menthol menthyl ester of valine (ment-Val) alone elevated the transcript level of defense genes, and it did so only at the low dose of 1 µM, not at higher or lower doses tested. Moreover, it appeared that histone acetylation was involved in this effect. Application of ment-Val enabled soybean plants to sustain the increased transcript levels in their leaves for up to 3 days. Moreover, when ment-Val was additionally applied at day 4, at which time the transcript level had declined to the basal level, the transcript level was re-elevated, indicating the possibility that ment-Val could be repeatedly used to sustain pest control. Ment-Val was found to be chemically stable and effective for defense of several crop species. Collectively, these data show that terpenoid conjugates are useful for pest control instead of or in addition to pesticides.

Amino acid-derived bisphenolate palladium complexes as C-C coupling catalysts

A series of amine bisphenol (ABP) pro-ligands featuring amino acid ester pendant arms were prepared. Optimisation of the synthetic method allowed the facile incorporation of naturally occurring, chiral amino acids...