Amyl Xyloside, a Selective Sugar-Based Hydrotrope for the Aqueous Extraction of Carnosic Acid from Rosemary

Abstract

Rosemary (Rosmarinus officinalis L.) is a Mediterranean herb known for its high antioxidant power that has been widely attributed to carnosic acid (CA). Passive extractions of CA have been performed in water by using five commercially available short-chain alkyl polyglycosides (APG) with alkyl chain lengths ranging from 4 to 10 carbon atoms and polar heads composed of pentoses and/or glucoses. APGs are nontoxic amphiphiles with high biodegradability. Their solubilizing capacity for CA has been determined, highlighting heptyl glucoside (C7Glu) as the most efficient one, followed by 2-ethylhexyl glucoside (C6,–2Glu) and isoamyl xyloside (iC5Xyl). However, iC5Xyl exhibited the highest selectivity toward CA solubilization as compared to ursolic acid (UA), a potential coextracted compound of rosemary leaves. In addition, it was found to be the most efficient amphiphile to extract CA from both ground and whole rosemary leaves. To optimize the maceration process and the recovery of the extract, a full factorial design 24 was performed investigating iC5Xyl concentration, temperature, stirring, and extraction time. A high concentration of hydrotrope was found to be the most important condition to optimize the maceration step, while the temperature particularly increases the yield, but in detriment of the CA content in the final dried extract.

Improved Hydrotropic Extraction of Carnosic Acid from Rosemary and Sage with Short-Chain Monoalkyl Glycerol Ethers

“…41 It is worth noting that if all available CA is extracted from rosemary with a plant:solution ratio of 1:10 (g:mL), only 2.7 g/L will be present in the solution, as indicated by the red dotted line. 26 According to Figure 1, only 15 wt % C 4 Gly are required to solubilize such amounts of CA. Regarding sage, a CA concentration of 1.85 g/ L will be reached after an extraction if all available CA is recovered.…”

“…More interestingly, a 30 wt % solution of C 4 Gly seems to be more efficient than C 4 E 2 and iC 5 Xyl to solubilize CA, with up to 46 g/L quantified in the solution. 25,26 For C 5 Gly and iC 5 Gly, solubility curves could not be determined because a phase separation occurred before any saturation could be reached when CA was added, as shown for C 5 Gly in Figure 2. A residual solid was observed only below 5 wt % of C 5 Gly, and no CA was detected in the supernatant by HPLC analysis.…”

Design and Properties of a Novel Family of Nonionic Biobased Furanic Hydroxyester and Amide Surfactants

“…Considering their wide range of applications and the very large quantities used in the everyday life, , surfactants are the object of intense academic and industrial research. In a longer term research strategy, it is crucial to diversify their molecular design and explore novel resources offering the opportunity for introducing more renewable carbon in the final products. − These approaches are complementary to the development of more classical systems derived from the etherification or esterification of polyols (e.g., carbohydrates, glycerol, sorbitan, isosorbide, erythritol). − …”

Surface Properties and Liquid Crystal Properties of Alkyltetra(oxyethyl) β-d-Glucopyranoside

“…Driven by the green concept of peaking global carbon dioxide emissions and achieving carbon neutrality by midcentury, surfactants synthesized from natural raw materials have no doubt become popular as ecologically suitable alternatives to their synthetic counterparts derived from petrochemical resources in the context of increasing the global awareness and social consciousness about carbon footprint, eco-environmental issues, and human safety. , Among them, alkyl polyglycosides (APGs) are well-known green and environmentally friendly nonionic surfactants that can be easily synthesized from renewable raw materials such as glucose and xylose hydrolyzed from agricultural waste and corn, and as well natural fatty alcohols. , Compared with traditional surfactants, nonionic sugar-based surfactants APGs and alkyl glycosides (AGs) with 1,2-cis or 1,2-trans anomeric pure have excellent industrial applications and medicine since they have conspicuous surface activity, desirable biodegradability, antifungal activity, no to low cytotoxicity/irritancy, and satisfactory biocompatibility and less negative impact on the environmental microorganism . In addition, it is noteworthy that the structures of such an emerging broad class of glycosurfactants are very diverse, and its attractive characteristics could be facilely adjusted by changing the sugar headgroup or nonpolar tail.…”

“…1,6 Among them, alkyl polyglycosides (APGs) are well-known green and environmentally friendly nonionic surfactants that can be easily synthesized from renewable raw materials such as glucose and xylose hydrolyzed from agricultural waste and corn, and as well natural fatty alcohols. 7,8 Compared with traditional surfactants, nonionic sugar-based surfactants APGs and alkyl glycosides (AGs) with 1,2-cis or 1,2-trans anomeric pure have excellent industrial applications and medicine since they have conspicuous surface activity, desirable biodegradability, antifungal activity, 9 no to low cytotoxicity/irritancy, 10 and satisfactory biocompatibility and less negative impact on the environmental microorganism. 11 In addition, it is note- worthy that the structures of such an emerging broad class of glycosurfactants are very diverse, and its attractive characteristics could be facilely adjusted by changing the sugar headgroup or nonpolar tail.…”