Supercritical fluid technologies offer a propitious method for drug discovery from natural sources. Such methods require relatively short processing times, produce extracts with little or no organic co-solvent, and are able to extract bioactive molecules whilst minimising degradation. Supercritical fluid extraction (SFE) provides a range of benefits, as well as offering routes to overcome some of the limitations that exist with the conventional methods of extraction. Unfortunately, SFE-based methods are not without their own shortcomings; two major ones being: (1) the high establishment cost; and (2) the selective solvent nature of CO₂, i.e., that CO₂ only dissolves small non-polar molecules, although this can be viewed as a positive outcome provided bioactive molecules are extracted during solvent-based SFE. This review provides an update of SFE methods for natural products and outlines the main operating parameters for extract recovery. Selected processing considerations are presented regarding supercritical fluids and the development and application of ultrasonic-assisted SFE methods, as well as providing some of the key aspects of SFE scalability.

Phylogenetic analysis of the ketosynthase (KS) gene sequences of marine sponge-derivedSalinisporastrains of actinobacteria indicated that the polyketide synthase (PKS) gene sequence most closely related to that ofSalinisporawas the rifamycin B synthase ofAmycolatopsis mediterranei. This result was not expected from taxonomic species tree phylogenetics using 16S rRNA sequences. From the PKS sequence data generated from our sponge-derivedSalinisporastrains, we predicted that such strains might synthesize rifamycin-like compounds. Liquid chromatography-tandem mass spectrometry (LC/MS/MS) analysis was applied to one sponge-derivedSalinisporastrain to test the hypothesis of rifamycin synthesis. The analysis reported here demonstrates that thisSalinisporaisolate does produce compounds of the rifamycin class, including rifamycin B and rifamycin SV. A rifamycin-specific KS primer set was designed, and that primer set increased the number of rifamycin-positive strains detected by PCR screening relative to the number detectable using a conserved KS-specific set. Thus, theSalinisporagroup of actinobacteria represents a potential new source of rifamycins outside the genusAmycolatopsisand the first recorded source of rifamycins from marine bacteria.

Chronic inflammation is linked with the generation and progression of various diseases such as cancer, diabetes and atherosclerosis, and anti-inflammatory drugs therefore have the potential to assist in the treatment of these conditions. Carica papaya is a tropical plant that is traditionally used in the treatment of various ailments including inflammatory conditions. A literature search was conducted by using the keywords “papaya”, “anti-inflammatory and inflammation” and “immunomodulation and immune” along with cross-referencing. Both in vitro and in vivo investigation studies were included. This is a review of all studies published since 2000 on the anti-inflammatory activity of papaya extracts and their effects on various immune-inflammatory mediators. Studies on the anti-inflammatory activities of recognized phytochemicals present in papaya are also included. Although in vitro and in vivo studies have shown that papaya extracts and papaya-associated phytochemicals possess anti-inflammatory and immunomodulatory properties, clinical studies are lacking.