Discovery of 1H-pyrazolo[3,4-b]pyrazine derivatives as selective allosteric inhibitor of protein tyrosine phosphatase SHP2 for the treatment of KRASG12C-mutant non-small cell lung cancer.

The high expression or mutation of SHP2 can induce cancer, so targeting SHP2 has become a new strategy for cancer treatment. In this study, we used the previously reported SHP2 allosteric inhibitor IACS-13909 as a lead drug for structural derivation and modification, and synthesized three SHP2 inhibitors. Among them, 1H-pyrazolo[3,4-b]pyrazine derivative 4b was a highly selective SHP2 allosteric inhibitor, with an IC50 value of 3.2 nM, and its inhibitory activity was 17.75 times than that of the positive control IACS-13909. The cell proliferation experiment detected that compound 4b would markedly inhibit the proliferation of various cancer cells. Interestingly, compound 4b was highly sensitive to KRASG12C-mutant non-small cell lung cancer NCI-H358 cells, with an IC50 value of 0.58 µM and its antiproliferative activity was 4.79 times than that of IACS-13909. Furthermore, the combination therapy of compound 4b and KRASG12C inhibitor sotorasib would play a strong synergistic effect against NCI-H358 cells. The western blot experiment detected that compound 4b markedly downregulated the phosphorylation levels of ERK and AKT in NCI-H358 cells. Molecular docking study predicted that compound 4b bound to the allosteric site of SHP2 and formed H-bond interactions with key residues Thr108, Glu110, Arg111, and Phe113. In summary, this study aims to provide new ideas for the development of SHP2 allosteric inhibitors for the treatment of KRASG12C mutant non-small cell lung cancer.Communicated by Ramaswamy H. Sarma.

Discovery of ellagic acid as a competitive inhibitor of Src homology phosphotyrosyl phosphatase 2 (SHP2) for cancer treatment: In vitro and in silico study.

Targeting SHP2 has become a potential cancer treatment strategy. In this study, ellagic acid was first reported as a competitive inhibitor of SHP2, with an IC50 value of 0.69 ± 0.07 µM, and its inhibitory potency was 34.86 times higher that of the positive control NSC87877. Ellagic acid also had high inhibitory activity on the SHP2-E76K and SHP2-E76A mutants, with the IC50 values of 1.55 ± 0.17 µM and 0.39 ± 0.05 µM, respectively. Besides, the IC50 values of ellagic acid on homologous proteins SHP1, PTP1B, and TCPTP were 0.93 ± 0.08 µM, 2.04 ± 0.28 µM, and 11.79 ± 0.83 µM, with selectivity of 1.35, 2.96, and 17.09 times, respectively. The CCK8 proliferation experiment exhibited that ellagic acid would inhibit the proliferation of various cancer cells. It was worth noting that the combination of ellagic acid and KRASG12C inhibitor AMG510 would produce a strong synergistic effect in inhibiting NCI-H358 cells. Western blot experiment exhibited that ellagic acid would downregulate the phosphorylation levels of Erk and Akt in NCI-H358 and MDA-MB-468 cells. Molecular docking and molecular dynamics studies revealed the binding information between SHP2 and ellagic acid. In summary, this study provides new ideas for the development of SHP2 inhibitors.

Design, synthesis, activity and molecular dynamics studies of 1,3,4-thiadiazole derivatives as selective allosteric inhibitors of SHP2 for the treatment of cancer.

Overexpression or gene mutation of SHP2 is closely linked with a variety of cancers and has been identified as a crucial anticancer target. In the study, we took SHP2 allosteric inhibitor SHP099 as the lead compound, and 32 1,3,4-thiadiazole derivatives were identified as selective allosteric inhibitors of SHP2. In vitro enzyme activity test showed that some compounds had high inhibition on full length SHP2, and almost no activity on homologous protein SHP1, exhibiting high selectivity. Compound YF704 (4w) had the best inhibition activity, with IC50 value of 0.25 ± 0.02 µM, and also showed strong inhibitory activity on SHP2-E76K and SHP2-E76A, with IC50 values of 6.88 ± 0.69 µM and 1.38 ± 0.12 µM, respectively. CCK8 proliferation test found that multiple compounds would effectively inhibit the proliferation of a variety of cancer cells. Among them, the IC50 values of compound YF704 on MV4-11 and NCI-H358 cells were 3.85 ± 0.34 µM and 12.01 ± 0.62 µM, respectively. Specially, these compounds were sensitive to NCI-H358 cells containing KRASG12C mutation, thus overcoming the problem that SHP099 was insensitive to such cells. Apoptosis experiment showed that compound YF704 would effectively induce apoptosis of MV4-11 cells. Western blot showed that compound YF704 would downregulate the phosphorylation levels of Erk1/2 and Akt in MV4-11 and NCI-H358 cells. Molecular docking study show that compound YF704 would effectively bind to the allosteric region of SHP2 and form hydrogen bond interactions with key residues Thr108, Arg111 and Phe113. Molecular dynamics study further revealed the binding mechanism of SHP2 and compound YF704. In conclusion, we hope to provide potential SHP2 selective inhibitors and provide valuable clues for cancer treatment.

Identification of natural product inhibitors of PTP1B based on high-throughput virtual screening strategy: In silico, in vitro and in vivo studies.

Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of the insulin signaling pathway, which is a potential therapeutic target for the treatment of type 2 diabetes mellitus (T2DM). In this study, we identified several PTP1B inhibitors with high activity by using high-throughput virtual screening and in vitro enzyme inhibition activity verification strategies. Among them, baicalin was first reported as a selective mixed inhibitor of PTP1B, with IC50 value of 3.87 ± 0.45 µM, and its inhibitory activity against homologous proteins TCPTP, SHP2, and SHP1 exceeded 50 µM. Molecular docking study found that baicalin and PTP1B could bind stably, and revealed that baicalin had a dual inhibitory effect. Cell experiments showed that baicalin was almost non-toxic and could significantly enhance the phosphorylation of IRS-1 in C2C12 myotube cells. Animal experiments showed that baicalin could significantly reduce the blood sugar of STZ-induced diabetic mice models, and had a liver protective effect. In conclusion, this study can provide new ideas for the development of PTP1B selective inhibitors.

Identification of the novel natural product inhibitors of SHP2 from the plant Toona sinensis: In vitro and in silico study.

In this study, we tested the inhibitory activity of 45 natural products extracted from the plant Toona sinensis on SHP2 protein, and identified four natural product inhibitors. The natural product 1,2,3,6-Tetragalloylglucose (A-1) was first reported as a competitive inhibitor of SHP2, with an IC50 value of 0.20 ± 0.029 µM and the selectivity of 1.8-fold and 4.35-fold to high homologous proteins SHP1 and PTP1B, respectively. Compound A-1 also showed high inhibitory activity on SHP2-E76K and SHP2-E76A mutants, with IC50 values of 0.95 ± 0.21 µM and 0.29 ± 0.045 µM, respectively. Cell viability assay showed that compound A-1 could inhibit the proliferation of a variety of cancer cells. Apoptosis assay showed that compound A-1 could effectively induce apoptosis of KRASG12C-mut NCI-H23 and KRASG12S-mut A549 cells. Western blot assay showed that compound A-1 could down regulate the phosphorylation levels of Erk1/2 and Akt in NCI-H23 and A549 cells. Molecular docking showed that compound A-1 could effectively dock to the catalytic active region of SHP2. Molecular dynamics simulation explored the effect of compound A-1 on SHP2, revealing the deep-seated binding mechanism. This study would provide valuable clues for the development of SHP2 and its mutant inhibitors.

[Investigation and application of Dendrobium resources in Qinba Mountains with a discussion on industrial poverty alleviation model].

The Dendrobium species are rare and endangered medicinal plants, and it is difficult to investigate their wild resources with conventional methods because of typical epiphytic herbaceous. We explored Dendrobium resources(include culture resource) of Qinba Mountains and the boundary Mountain area in Hubei, Chongqing using the methods of literatures and field investigation, and found that the cultural base of Dendrobium were profound in Qinba Mountains region. Furthermore, its germplasm resources of Dendrobium were established for the first time in Wanzhou Luotian town. In case the advantages of local rock resources and poverty alleviation demand, we have actively carried out the cultivating mode of Dendrobium which grow on rock, and the poverty alleviation model of local characteristic Dendrobium industry were established preliminarily. Our application case can provide reference for the mining and transformation of traditional Chinese medicine resources census results.

[Original materials of traditional Chinese medicinal names of "Jinchai" and "Jinchai Shihu" based on vegetative morphology].

"Jinchai Shihu" were called Jinchai and recoded in "Taishang Zhouhou Yujingfang" of Tang Dynasty, which first clearly documented the name of Shihu in complex Dendrobium medicines and were condiered as superior medicinal articles. Morphological features are one of the naming principles for Chinese medicines. In this paper, botanical origin plants under the names of "Jinchai" and "Jinchai Shihu" were investigated. Based on documents from the local Chronicles and historical accounts, the Chinese characters of Jinchai have the distinctive features of gold color and two hair clasps. Moreover, the hair clasps are usually cylindrical in shape with uniform thickness in middle and upper part, and tapers off to the foot. And its bottom part style is simple and head part is complex. Thus we speculated the herbal "Jinchai" and "Jinchai Shihu" should have similar morphologic features as Chinese characters of Jinchai, including golden color and hairpin shape of stems without braches, short and solid sterm. After comparing the dried vegetative morphology of 10 common medicinal Dendrobium species, we suggested that of Dendrobium flexicaule matches well with the morphological features from historical herbal records.

[Textual research on origin and genuine of Lilii Bulbus].

Lilii Bulbus, which comes from many medicinal plants，is a frequently-used traditional Chinese medicine，the records in previous herbal literatures of it's origin and quality were inconstant. To trace back it's sources, we conducted a systematical study on it's origin and quality by textual research and investigation in this paper,The result showed that the origins of Lilii Bulbus are mainly source from white-flowers, red-yellow-flowers and red-flowers of Lilium， L. brownii var. viridulum, which were believed authentic or good quality in all previous herbal literatures,and L. pumilum and L. concolor which belong to white-flowers,and L. lancifolium which belong to red-yellow-flowers were believed low-quality and unfit for medicinal uses, or they were listed below and often have different effect with L. brownii var. viridulum. Among them, only L. concolor does not belong to Lilii Bulbus according to Chinese Pharmacopeia (2015 edition), The mainstream varieties of Lilii Bulbus became L. lancifolium now according to our practical investigation, which were very different from previous herbal literatures. Although chemical and pharmacological studies provided a reference for L. lancifolium，we should respect the actual records of the previous herbal literatures，the research of material foundation of efficacy should be more sufficient，and provide science evidence for clinical application of different species of Lilii Bulbus.

[Resources and usage status of Tibetan medicinal plant "Bangga"].

The study is aimed to clarify the actual original plant, find out the usage status and the resource distribution of the Tibetan medicinal plant "Bangga". By using the way of the literatures survey, interview and investigation, it found out that the actual original plant of the Tibetan medicinal plant "Bangga" were the whole dried plant or the aerial part of Aconitum tanguticum or A. naviculare of Ranunculaceae, among which A. tanguticummainly distributed in Sichuan, Gansu, Qinghai, Tibet (Qamdo), and A. naviculare mainly distributed in Tibet. Sichuan, Gansu, Qinghai and other Tibetan areas mainly used the resources of A. tanguticum, Tibet (except the Qamdo area) mainly uses the A. naviculare, which resource was imminent in danger. Other species described in the literature were not used. It showed that the use of herbs related to their resources, it is recommended to strengthen the protection and guide the market.

[Investigation of original materials under traditonal Chinese medicine names of "Jinchai" and "Jinchai Shihu"].

To clear from botanical view the original materials under the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" within the genus Dendrobium of the family Orchidaceae. Combined of different methods including study of historical records from the local chronicles and historical accounts of past event in Hubei, Sichuan, Chongqing, Henan and Shaanxi provinces, interviewing face to face with the old traditional Chinese workers and folk doctors in 20 downtowns and countrysides, such as, Laohekou, Lichuan, Fangxian, Xixia, Neixiang, and Ankang, and collecting a few plants of "Jinchai" for taxonomic identification. The traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" were widely used by the local people from the eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, western Henan. Those two names were frequently found in the local Chronicles and historical accounts of past event, even in the local daily life such as folk songs and stories. The botanical identification results showed that a endemic species of D. flexicaule is the original materials of the traditional Chinese medicine names "Jinchai" and "Jinchai Shihu", and this species are also called "Longtoujin", "Renzijin", "Huanzijin" and "Longtoufengweijin" by the local people. The dried artifactitious specimens of D. flexicaule are traditionally named as "Jinerhuan". The botanic resource plants of the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" are the endemic species of D. flexicaule that is distributed mainly in central areas of China including eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, and western Henan, rather than D. nobile as referring in both Chinese and English version of Flora of China, and in official recorded serious versions of The Chinese Pharmacopoeia since 1977. In order to avoid confusion in the traditional Chinese medicine dendrobiums industry, the Chinese name of D. nobile is suggested as "Biancao Shihu", which characterized one stem feature of this species, and the traditional Chinese medicine names "Jinchai" or "JinchaiShihu" is suggested to refer to the species D. flexicaule.

[Effect of topographical factors on podophyllotoxin content in Sinopodophyllum hexandrum and study on ecological suitability].

In order to find the optimal topographical factor for regionslization, the content of cimetidine in 116 Sinopodophyllum hexandrum sample collected from Sichuan, Qinghai, Gansu, Tibet, Yunnan and Shaanxi provinces, was determined. Using mathematical statistics and geographical spatial analysis of GIS analysis, the relationship between content of podophyllotoxin and influencing factors including altitude gradient and gradient position was analyzed. It is found that the optimal altitude was 2 800 m to 3 600 m, the aspect of slope north or northeast and northwest and the slope 12 degrees to 65 degrees with a high suitability degree. Considering the artificial planting, the suitable planting area for S. hexandrum is comfirmed. The topographical factor is important for S. hexandrum regionalization, but has hardly effect on podophyllotoxin content. The results of the study provide an important scientific basis for S. hexandrum production development. But there are many factors which affect suitability index and podophyllotoxin content of S. hexandrum, it is necessary to consider other factors like climate and soil while exploitation and protection of S. hexandrum.

[Studies on main interspecific association of rare and endangered medicinal plant Sinopodophyllum hexandrum community in Kangding Zheduo mountain of Sichuan province].

Based on the 2 x 2 contingency table, by using multi-species relevance (variance ratio, VR), chi2-test, Ochiai index, Dice index, Jaccard index, t-test of v/x and F-test of Morisita, s index, the interspecific relationships and the spatial distribution pattern between 20 dominants in Kangding Zheduo Mountain of Sichuan province were studied. The results indicated that the interspecific association between dominants of Sinopodophyllum hexandrum community in this area did not show significant association, which suggested that the S. hexandrum community was in mature stage, and showed stronger independency, among total 190 pairs in 20 dominant species, 2 species pairs exhibited extremely significantly positive association, 12 species pairs showed significantly positive association, 6 species pairs exhibited significantly negative association and there were no pairs showed extremely significantly negative association. S. hexandrum in community did not show significant association, which indicates they are independent in community, the spatial distribution pattern of S. hexandrum is characterized by random distribution.

[Microscopic identification of tibetan medicinal herb "Songdi" (Saxifraga umbellulata var pectinata)].

OBJECTIVE: To establish a method of microscopic identification of Tibetan medicinal herb " Songdi" (Saxifraga umbellulata var. pectinata). METHOD: The different characteristics and microscopic identification of 4 species of Songdi were compared, including the main variety (Saxifraga umbellulata var. pectinata ) and approximate varieties (S. unguiculata, S. przewalskii and S. tanguTi,) were studied and compared. RESULT: The botanical anatomy characteristics of Saxifraga umbellulata var. pectinata (including roots, stems, leaves, flowers, stalks and fruits) have been measured. The methods for powder identifications and transverse section of stems root and leaves of four species of Songdi were established. CONCLUSION: Four species of Songdi can be identified by the growth pattern of basal leaves, type of hair, type of inflorescence, number of flowers, proportion of tissue structures in stem, form of pollen grains.

[Genetic diversity and genetic structure of endangered wild Sinopodophyllum emodi by start codon targeted polymorphism].

OBJECTIVE: Revealed the genetic diversity level and genetic structure characteristics in Sinopodophyllum emodi, a rare and endangered species in China. METHOD: We detected the genetic polymorphism within and among six wild populations (45 individuals) by the approach of Start Codon Targeted (SCoT) Polymorphism. The associated genetic parameters were calculated by POP-GENE1.31 and the relationship was constructed based on UPGMA method. RESULT: A total of 350 bands were scored by 27 primers and 284 bands of them were polymorphic. The average polymorphic bands of each primer were 10.52. At species level, there was a high level of genetic diversity among six populations (PPB = 79.27%, N(e) = 1.332 7, H = 0.210 9 and H(sp) = 0.328 6). At population level, the genetic diversity level was low (PPB = 10.48% (4.00% -23.71%), N(e) = 1.048 7 (1.020 7-1.103 7), H = 0.029 7 (0.012 9-0.063 1), H(pop) = 0.046 2 (0.019 9-0.098 6). The Nei's coefficient of genetic differentiation was 0.841 1, which was consistent with the Shannon's coefficient of genetic differentiation (0.849 4). Two calculated methods all showed that most of the genetic variation existed among populations. The gene flow (N(m) = 0.094 4) was less among populations, indicating that the degree of genetic differentiation was higher. Genetic similarity coefficient were changed from 0.570 8 to 0.978 7. By clustering analysis, the tested populations were divided into two classes and had a tendency that the same geographical origin or material of similar habitats clustered into one group. CONCLUSION: The genetic diversity of samples of S. emodi is high,which laid a certain foundation for effective protection and improvement of germplasm resources.

[Evaluation of medicinal reasonableness and resource utilization of Dida (Zang Yin Cheng) commonly used in Tibetan medicine].

OBJECTIVE: To evaluate the medicinal reasonableness and resource utilization of Dida from different species. METHOD: With common characteristic absorption peaks of HPLC fingerprints and SPSS cluster, the composition similarity of Dida from different species was evaluated. RESULT: The composition similarity of HPLC fingerprints of 33 Dida samples from 15 species and 1 variety originated from Swertia, Halenia, Gentianopsis, Lomatogonium was difference. The original species can be clustered into four groups by the relative area of 10 common characteristic peaks of HPLC fingerprints. The compositions of four different genera are quite different. CONCLUSION: Because of containing iridoids, xanthones, and triterpenes which have liver protection and cholagogue functions, all of species from Swertia, Halenia, Gentianopsis and Lomatogonium in Gentianaceae are classified as Dida in Tibetan medicine. According to the composition difference among different species, the HPLC fingerprints established for Dida from different source are an effective means to identify nd control the quality of Dida.

[Determination and quality assessment of 10 ingredients gentiopicroside and sweroside and so on in Tibetan medicine Jia Di (Swertia chirayita)].

OBJECTIVE: To establish a method for determination of 10 ingredients such as gentiopicroside, sweroside, and mangiferin in India swertia, and settle the index components and their limits. METHOD: By Welch materials AQ-C18 column, determination was conducted by the gradient elution with methanol and 0.4% formic acid as mobile phase, with column temperature 30 degrees C, flow rate at 1.0 mL x min(-1), and 254 nm as the detection wavelength. RESULT: The linear relatives of 10 ingredients were good. The method showed the high precision and good reproducibility, and recovery rates were between 97% and 103%. The ingredients of market com-modities varied greatly. CONCLUSION: This method is simple, sensitive, reproducible, and applicable to the determination of the main ingredients in India Swertia. Sweroside and mango glycosides were suggested as the index components for determination in Jia Di (Swertia chirayita), and their content limits are not less than 0.1%, 0.3%, respectively.