What's in the box? Authentication of Echinacea herbal products using DNA metabarcoding and HPTLC.

Background: Differences in regulatory policies between countries as well as a lack of appropriate standardized methods for the authentication and quality control of herbal products directly impact their quality and safety. Echinacea products are among the top-selling herbal products in Europe and the United States with indications for a broad range of ailments. The increased use of Echinacea species has led to concerns about adulterated products resulting from challenges in morphology-based identification, due to overlapping morphological variation, frequent hybridization between species, and deliberate adulteration.

2D Stress Tensor for 4D Gravity.

We use the subleading soft-graviton theorem to construct an operator T_{zz} whose insertion in the four-dimensional tree-level quantum gravity S matrix obeys the Virasoro-Ward identities of the energy momentum tensor of a two-dimensional conformal field theory (CFT_{2}). The celestial sphere at Minkowskian null infinity plays the role of the Euclidean sphere of the CFT_{2}, with the Lorentz group acting as the unbroken SL(2,C) subgroup.

Color Memory: A Yang-Mills Analog of Gravitational Wave Memory.

A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test "quarks" initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks.

DNA metabarcoding of orchid-derived products reveals widespread illegal orchid trade.

In eastern Mediterranean countries orchids continue to be collected from the wild for the production of salep, a beverage made of dried orchid tubers. In this study we used nrITS1 and nrITS2 DNA metabarcoding to identify orchid and other plant species present in 55 commercial salep products purchased in Iran, Turkey, Greece and Germany. Thirty samples yielded a total of 161 plant taxa, and 13 products (43%) contained orchid species and these belonged to 10 terrestrial species with tuberous roots.

Benefits and Limitations of DNA Barcoding and Metabarcoding in Herbal Product Authentication.

Introduction: Herbal medicines play an important role globally in the health care sector and in industrialised countries they are often considered as an alternative to mono-substance medicines. Current quality and authentication assessment methods rely mainly on morphology and analytical phytochemistry-based methods detailed in pharmacopoeias. Herbal products however are often highly processed with numerous ingredients, and even if these analytical methods are accurate for quality control of specific lead or marker compounds, they are of limited suitability for the authentication of biological ingredients.