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Abstract We study the thermodynamic properties of asymmetric quark matter, large mass quark stars (QSs), and proto-quark stars (PQSs) within the quasiparticle model. Considering the effects of temperature within quasiparticle model can significantly influence the EOS and the entropy of strange quark matter (SQM), quark fractions in SQM, as well as the tidal deformability and the maximum mass of PQSs along the star evolution line. Our results indicate that the recent discovered heavy compact stars PSR J0348+0432, MSR J0740+6620, PSR J2215+5135, and especially the GW190814’s secondary component $$m_2$$ m 2 can be well described as QSs within the quasiparticle model. The tidal deformability for the QSs describing the heavy compact stars is extremely large, which can not well describe GW170817 as QSs, and the effects of the temperature in the heating process along the star evolution will further increase the tidal deformability and the maximum mass of PQSs.

Abstract We study the thermodynamic properties of asymmetric quark matter and large mass quark stars within the confined-isospin-density-dependent-quark-mass model. We find that the quark matter symmetry energy should be very large in order to describe the recent discovered heavy compact stars PSR J0348+0432 ( $$\text {2.01}\pm \text {0.04}M_{\odot }$$ 2.01 ± 0.04 M ⊙ ), MSP J0740+6620 ( $$\text {2.14}\pm ^\text {0.10}_\text {0.09}M_{\odot }$$ 2.14 ± 0.09 0.10 M ⊙ of 68.3 $$\%$$ % credibility interval and $$\text {2.14}\pm ^\text {0.20}_\text {0.18}M_{\odot }$$ 2.14 ± 0.18 0.20 M ⊙ of 95.4 $$\%$$ % credibility interval) and PSR J2215+5135 (2.27 $$\pm ^\text {0.10}_\text {0.09}M_{\odot }$$ ± 0.09 0.10 M ⊙ ) as QSs. The tidal deformability $$\Lambda _{1.4}$$ Λ 1.4 of the QSs is also investigated in this work, and the result indicates that $$\Lambda _{1.4}$$ Λ 1.4 may depend on the isospin effects and the strength / orientation distribution of the magnetic fields inside the quark stars.

Brefeldin A (1), a potent cytotoxic natural macrolactone, was produced by the marine fungus Penicillium sp. (HS-N-29) from the medicinal mangrove Acanthus ilicifolius. Series of its ester derivatives 2–16 were designed and semi-synthesized, and their structures were characterized by spectroscopic methods. Their cytotoxic activities were evaluated against human chronic myelogenous leukemia K562 cell line in vitro, and the preliminary structure–activity relationships revealed that the hydroxy group played an important role. Moreover, the monoester derivatives exhibited stronger cytotoxic activity than the diester derivatives. Among them, brefeldin A 7-O-2-chloro-4,5-difluorobenzoate (7) exhibited the strongest inhibitory effect on the proliferation of K562 cells with an IC50 value of 0.84 µM. Further evaluations indicated that 7 induced cell cycle arrest, stimulated cell apoptosis, inhibited phosphorylation of BCR-ABL, and thereby inactivated its downstream AKT signaling pathway. The expression of downstream signaling molecules in the AKT pathway, including mTOR and p70S6K, was also attenuated after 7-treatment in a dose-dependent manner. Furthermore, molecular modeling of 7 docked into 1 binding site of an ARF1–GDP-GEF complex represented well-tolerance. Taken together, 7 had the potential to be served as an effective antileukemia agent or lead compound for further exploration.