Inhibition of Phospholipase A2 and Platelet Aggregation by Grycyrrhizin, an Anti-inframmation Drug

We studied the effect of glycyrrhizin, a compound known as an anti-inflammatory and antiallergic drug, on the membrane permeability change induced by phospholipase A2 (PLA2) and on platelet aggregation. Glycyrrhizin was found to inhibit the PLA2-induced carboxyfluorescein (CF) release from D,L-dipalmitoyl phosphatidylcholine (DPPC) liposomes. Part of this inhibitory effect of glycyrrhizin on PLA2 is accounted for by the physical state of the substrate, the DPPC liposome membrane. Glycyrrhizin also inhibited collagen-induced platelet aggregation in a concentration dependent manner, which may in part account for its inhibitory effect on PLA2.</p

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Asymmetric Hydrogenation of Aromatic Heterocyclic Ketones Catalyzed by the MsDPEN–Cp*Ir(III) Complex

Asymmetric hydrogenation of aromatic heterocyclic ketones catalyzed by Cp*Ir(OTf)(Msdpen) (MsDPEN = N-(methanesulfonyl)-1,2-diphenylethylenediamine) affords the heterocyclic alcohols in 93% to > 99% ee. The reaction is conducted in a methanolic solution with a substrate-to-catalyst molar ratio of 200-5000 under 15 atm of H2. The heterocyclic rings of substrates are left intact

Asymmetric Hydrogenation of Polysubstituted Aromatic Ketones Catalyzed by the DIPSkewphos/PICA Derivative-Ruthenium(II) Complexes

The DIPSkewphos/PICA derivative-Ru(II) complexes catalyzed asymmetric hydrogenation of significantly sterically hindered 2',3',4',5',6'-pentamethylacetophenone, which was not reduced with NaBH4 at 25 degrees C, with a substrate-to-catalyst molar ratio (S/C) of 2000 under 50 atm of H-2 in a base-containing 2-propanol to afford the alcohol in 99% ee quantitatively. A series of polysubstituted aromatic ketones was smoothly reacted with an S/C of 300-10,000 under 10-50 atm of H-2, yielding the alcoholic products in up to 99% ee. The catalyst system achieved an industrial-scale (50 kg) hydrogenation of 2',6'-dichloro-3'-fluoroacetophenone, affording the alcohol in 96% isolated yield and in 98% ee. The obtained alcoholic product is known as a key intermediate for the synthesis of the medicine crizotinib