Associating chitosan and microemulsion as a topical vehicle for the administration of herbal medicines.

A viscous solution of low molecular weight chitosan (CH) at 5% w/v (10.2 kDa, 75 % deacetylated, 1451 cP at 25 °C) was associated with a microemulsion (ME) that undergoes a phase transition after water absorption in situ (≈28 % w/w), forming a more viscous liquid crystal, which was potentially evaluated as a topical vehicle. The ME was selected from a phase diagram, selecting a composition based on Tween® 80 (52 %), myristate isopropyl (28 %), and the aqueous phase (water and polyethylene glycol 400, 60:40 w/w) (20 %), which was after replaced by CH and herbal medicines (HM). HM are alternatives to treat candidiasis, and Stryphnodendron adstringens shell extract, characterized by molecular networking, and Melaleuca alternifolia Chell essential oil (46 % of terpinen-4-ol), showed in vitro activity against Candida albicans. Associating CH in ME improved the mechanical properties of the topical formulation, as adhesiveness, which is an advantageous feature for the topical treatment of vulvovaginal candidiasis.

Chemical Diversity in a Stingless Bee-Plant Symbiosis.

Bees are essential pollinators on earth, supporting forest equilibrium and human agriculture. The chemistry of the stingless bee-plant symbiosis is a complex and not completely understood phenomenon. Here, we combined untargeted tandem mass spectrometry, molecular networking, and multivariate statistical analysis to investigate the chemical diversity in colonies of the stingless bee Scaptotrigona depilis. Flavonoids were the most representative and diverse group of plant metabolites detected, indicating the importance of these biologically active natural products to the bees. We unveiled the metabolome, mapped the distribution of plant metabolites in stingless bee colonies, and digitized the chemical data into a public database.