Rhodium-catalyzed C-H carboxymethylation of anilines with vinylene carbonate.

A rhodium-catalyzed synthesis of phenylacetate has been realized by direct C-H carboxymethylation of anilines bearing removable directing groups. The reaction occurred most efficiently in air, without any external base or oxidant. This methodology is expected to provide a facile and general access to various bioactive 2-amino aromatic acetic acid derivatives.

Spatio-temporal distribution and overlap of Naemorhedus griseus and Capricornis milneedwardsii in Gongga Mountain, Sichuan, China.

Clarifying the distribution pattern and overlapping relationship of sympatric relative species in the spatio-temporal niche is important for our understanding of the behavioral relationship between species and the integrated management of multi-species habitats. Based on the infrared camera monitoring data from 2012 to 2021, we investigted the spatio-temporal distribution characteristics of the national secondary-class key protected animals Naemorhedus griseus and Capricornis milneedwardsii in the Gongga Mountain National Nature Reserve, Sichuan Province. We analyzed the distribution of N. griseuss and C. milneedwardsiis in the reserve using the MaxEnt model, based on 72 and 108 occurrence data of the two species, respectively, obtained by infrared cameras from 2016 to 2021, combined with 12 environmental factors potentially affecting their spatial distribution. Then, based on 1312 occurrence data of N. griseus and 1889 occurrence data of C. milneedwardsii collected by infrared camera from 2012 to 2021, we estimated their daily activity rhythms by using the kernel density estimation to understand the distribution pattern and overlap of the two species in the temporal niche. The results showed that the area of suitable habitats for N. griseus and C. milneedwardsii was 731.95 km2 and 1220.46 km2, respectively. The overlapping area was 697.17 km2. The main environmental factors had similar effects on the habitat selection of the two species. The daily activity of both species peaked in the early morning and evening. The utilization of the interval and intensity of the morning and evening time periods were different for the two species. The morning and evening activity peaks of C. milneedwardsii were earlier and later, respectively, than that of N. griseus. C. milneedwardsii had a higher utilization intensity during the nocturnal period. In general, high degree of spatial overlap and low degree of overlap in the temporal niche dimension contribute to the long-term coexistence of the two species.

C-H acylation of aniline derivatives with α-oxocarboxylic acids using ruthenium catalyst.

An efficient and convenient synthetic strategy for ruthenium(II)-catalyzed ortho-acylation of N-(2-pyridyl)-anilines using α-oxycarboxylic acids as acyl sources is described. The procedure can smoothly proceed under mild conditions, showing good functional group tolerance. Valuable ortho-acylated aniline products have been obtained with moderate to good yields. Furthermore, the reaction could be easily scaled up to the gram scale.

Rhodium-Catalyzed Azine-Directed C-H Amidation with N-Methoxyamides.

Using N-methoxyamide reagents as an amide source, C-H amidation was realized at the ortho position of azine under the action of rhodium and boric acid. The method has mild reaction conditions, high atomic utilization, excellent yield, and wide adaptability to amidation reagents (both aromatic amides and fatty amides are applicable). Amide-substituted ketones can be obtained by a simple treatment and can be further transformed into bioactive substances. This provides a good supplement for the C-H bond amidation of aromatic rings.

Rhodium-Catalyzed C(sp2)-H Amidation of Azine with Sulfonamides.

Direct C-H amidation of azine with sulfonamide was developed for the first time. The reactions proceeded smoothly under benign conditions and gave the corresponding products with high selectivity. This approach shows high regioselectivity, wide substrate scope, and functional group tolerance. Additionally, this transformation can also be scaled up to the gram level. This strategy allows for the direct preparation of ortho-sulfonamide-substituted ketone products, thus providing a good complement to previous C-H amidation.

[Application of relative quality constant in grades evaluation of bran stir-baked Aurantii Fructus].

The specifications of Chinese herbal medicines naturally form and exist in the circulation and use of Chinese herbal medicines.Buyers and sellers negotiate price by quality. With the increasing demand for public health care,the cultivation,processing methods and circulation of Chinese herbal medicines have changed. Under the mode of pursuing output and short-term benefits,the traditional grade evaluation method has been difficult to apply to the current quality status of the pieces. Bran stir-baked Aurantii Fructus is a genuine medicinal material in Jiangxi province. It is widely used,but the quality level of bran stir-baked Aurantii Fructus on the market is not uniform. Quality constant method was used in this paper for grading the Chinese herbal slices of bran stir-baked Aurantii Fructus. Sixteen batches of different quality samples were collected and tested,and finally,eleven qualified batches of them were chosen as researcher objects. The results showed that the relative quality constant ranged from 2. 52 to 5. 60. The relative quality constant was ≥4. 48 for first grade bran stir-baked Aurantii Fructus,2. 80-4. 48 for the second grade pieces,and <2. 80 for the third grade pieces. The grades evaluation method for bran stir-baked Aurantii Fructus established in this paper included both appearance and index composition. The results were objective,accurate,quantitative,applicable,and the method was simple to operate and easy to popularize. This study showed that the quality constant method could be applied to the grade evaluation of bran stir-baked Aurantii Fructus,providing a reference for the grade evaluation of fruit-type decoction pieces.

Risk factors for postoperative stroke in adults patients with moyamoya disease: a systematic review with meta-analysis.

BACKGROUND: This systematic review and meta-analysis aimed to clarify the risk factors for postoperative stroke in adult patients with moyamoya disease (MMD). METHODS: We comprehensively searched MEDLINE/PubMed, Web of Science, and Cochrane Library for eligible published literature with regard to the risk factors and postoperative complications in adult patients with MMD. Statistical analysis was conducted using Stata version 12.0. Pooled odds ratio (OR) with 95% confidence interval (CI) were assessed for each risk factor. RESULTS: There were 8 studies encompassing 1649 patients who underwent surgery with MMD were selected for analysis. Preoperative ischemic event significantly increase the risk of postoperative stroke events (OR = 1.40; 95%CI = 1.02-1.92; P = 0.039). PCA involvement correlate with an increased risk of post-infarction (OR = 4.60; 95%CI = 2.61-8.11; P = 0.000). Compared to direct bypass, patients who underwent indirect bypass or combined bypass could significantly increase the risk of postoperative stroke events. (OR = 1.17; 95%CI = 1.03-1.33; p = 0.017). MMD patients with diabetes were associated with an increased risk of postoperative stroke events (OR = 4.02, 95% CI = 1.59-10.16; p = 0.003). MMD patients with hypertension, age at onset and male sex were not associated with an increased risk of postoperative stroke events (P > 0.05). CONCLUSIONS: This systematic review and meta-analysis indicated that preoperative ischemic events, PCA involvement and diabetes were independent risk factors for postoperative stroke in MMD patients. Therefore, in order to ensure the curative effect of patients with MMD, it is very necessary to detect these risk factors and prevent postoperative complications in time.

A facile three-step total synthesis of tanshinone I.

A facile synthetic approach for total synthesis of tanshinone I has been accomplished. The key precursor is a novel compound, epoxy phenanthraquinone. And this synthesis of tanshinone I is achieved in only three simple stages, which include Diels-Alder reaction, Δ(2)-Weitz-Scheffer-type epoxidation, and Feist-Bénary reaction from commercially available styrene.

Reversal of P-gp and BCRP-mediated MDR by tariquidar derivatives.

With an aim to generate non-toxic, specific and highly potent multidrug resistance (MDR) modulators, a novel series of anthranilic acid amide-substituted tariquidar derivatives were synthesized. The new compounds were evaluated for their cytotoxicity toward normal human colon fibroblasts (CCD18-Co), human gastric epithelial cell line (HFE) and primary rat liver cells, and for their ability to inhibit P-gp/BCRP-mediated drug efflux and reversal of P-gp and BCRP-mediated MDR in parental and drug-resistant cancer cell lines (LCC6 MDR1, MCF-7 FLV1000, R-HepG2, SW620-Ad300). While tariquidar is highly toxic to normal cells, the new derivatives exhibited much lower or negligible cytotoxicity. Some of the new tariquidar derivatives inhibited both P-gp and BCRP-mediated drug efflux whereas a few of them bearing a sulfonamide functional group (1, 5, and 16) are specific to P-gp. The new compounds were also found to potentiate the anticancer activity of the transporter substrate anticancer drugs in the corresponding transporter-overexpressing cell lines. The extent of resistance reversal was found to be consistent with the transporter inhibitory effect of the new derivatives. To further understand the mechanism of P-gp and BCRP inhibition, the tariquidar derivatives were found to interact with the transporters using an antibody-based UIC2 or 5D3 shift assay. Moreover, the transporters-inhibiting derivatives were found to modulate the ATPase activities of the two MDR transporters. Our data thus advocate further development of the new compounds for the circumvention of MDR.

Evaluation and SAR analysis of the cytotoxicity of tanshinones in colon cancer cells.

AIM: This study was designed to evaluate the anti-cancer actions of tanshinone I and tanshinone IIA, and six derivatives of tanshinone IIA on normal and cancerous colon cells. Structure activity relationship (SAR) analysis was conducted to delineate the significance of the structural modifications of tanshinones for improved anti-cancer action. METHOD: Tanshinone derivatives were designed and synthesized according to the literature. The cytotoxicity of different compounds on colon cancer cells was determined by the MTT assay. Apoptotic activity of the tanshinones was measured by flow cytometry (FCM). RESULTS: Tanshinone I and tanshinone IIA both exhibited significant cytotoxicity on colon cancer cells. They are more effective in p53(+/+) colon cancer cell line. It was also noted that the anti-cancer activity of tanshinone I was more potent and selective. Two of the derivatives of tanshinone IIA (N1 and N2) also exhibited cytotoxicity on colon cancer cells. CONCLUSION: The anti-colon cancer activity of tanshinone I was more potent and selective than tanshinone IIA, and is p53 dependent. The derivatives obtained by structural modifications of tanshinone IIA exhibited lower cytotoxicity on both normal and colon cancer cells. From steric and electronic characteristics point of view, it was concluded that structural modifications of ring A and furan or dihydrofuran ring D on the basic structure of tanshinones influences the activity. An increase of the delocalization of the A and B rings could enhance the cytotoxicity of such compounds, while a non-planar and small sized D ring region would provide improved anti-cancer activity.

Eremophilenolides and other constituents from the roots of Ligularia sagitta.

Chemical investigation of the roots of Ligularia sagitta has resulted in the characterization of six eremophilenolides 6beta,8beta-dimethoxy-10beta-hydroxyeremophil-7(11)-en-12,8alpha-olide (1), 6beta-angeloyloxy-10beta-hydroxy-8beta-methoxyeremophil-7(11)-en-12,8alpha-olide (2), 6beta-(2'-methylbutanoyloxy)-10beta-hydroxy-8beta-methoxyeremophil-7(11)-en-12,8alpha-olide (3), 6beta-angeloyloxy-10beta-hydroxy-8alpha-methoxyeremophil-7(11)-en-12,8beta-olide (4), 6beta-(2'-methylbutanoyloxy)-10beta-hydroxy-8alpha-methoxyeremophil-7(11)-en-12,8beta-olide (5) and 8beta,10beta-dihydroxy-6beta-methoxyeremophil-7(11)-en-12,8alpha-olide (6), together with one monoterpene (3 R,4 R,6 S)-3,6-dihydroxy-1-menthene (7), two triterpenes lupeol (8) and ursolic acid (9), and beta-sitosterol (10). The structures of five new constituents (1-5) were elucidated by spectroscopic methods including 2D-NMR experiments. The compounds 1, 5 and 7 showed antibacterial activity by being assayed against Staphylococcus aureus, Bacillus subtilis and Escherichia coli.