Putrescine, a biogenic amine, is a highly valued compound in medicine, industry, and agriculture. In this study, we report a whole-cell biocatalytic method in Escherichia coli for the production of putrescine, using L-arginine as the substrate. L-arginine decarboxylase and agmatine ureohydrolase were co-expressed to produce putrescine from L-arginine. Ten plasmids with different copy numbers and ordering of genes were constructed to balance the expression of the two enzymes, and the best strain was pACYCDuet-speB-speA. The optimal concentration of L-arginine was determined to be 20 mM for this strain. The optimum pH of the biotransformation was 9.5, and the optimum temperature was 45 °C; under these conditions, the yield of putrescine was 98%. This whole-cell biocatalytic method appeared to have great potential for the production of putrescine.

This paper is intended to review advances in the botanical, phytochemical, traditional uses and pharmacological studies of the genus Trachelospermum. Until now, 138 chemical constituents have been isolated and characterized from these plants, particularly from T. asiaticum and T. jasminoides. Among these compounds, lignans, triterpenoids, and flavonoids are the major bioactive constituents. Studies have shown that plants from the genus Trachelospermum exhibit an extensive range of pharmacological properties both in vivo and in vitro, including anti-inflammatory, analgesic, antitumor, antiviral and antibacterial activities. In Traditional Chinese Medicine (TCM) culture, drugs that include T. jasminoides stems have been used to cure rheumatism, gonarthritis, backache and pharyngitis, although there are few reports concerning the clinical use and toxicity of these plants. Further attention should be paid to gathering information about their toxicology data, quality-control measures, and the clinical value of the active compounds from genus Trachelospermum.

Preterm white matter injury (PWMI) is the most common form of brain damage in premature infants caused by hypoxia-ischemia (HI), inflammation, or excitotoxicity. It is characterized by oligodendrocyte precursor cell (OPC) differentiation disorder and dysmyelination. Our previous study confirmed that alpha-asarone (α-asaronol), a major compound isolated from the Chinese medicinal herb Acorus gramineus by our lab, could alleviate neuronal overexcitation and improve the cognitive function of aged rats. In the present study, we investigated the effect and mechanism of α-asaronol on myelination in a rat model of PWMI induced by HI. Notably, α-asaronol promoted OPC differentiation and myelination in the corpus callosum of PWMI rats. Meanwhile, the concentration of glutamate was significantly decreased, and the levels of PPARγ and glutamate transporter 1 (GLT-1) were increased by α-asaronol treatment. In vitro, it was also confirmed that α-asaronol increased GLT-1 expression and recruitment of the PPARγ coactivator PCG-1a in astrocytes under oxygen and glucose deprivation (OGD) conditions. The PPARγ inhibitor GW9662 significantly reversed the effect of α-asaronol on GLT-1 expression and PCG-1a recruitment. Interestingly, the conditioned medium from α-asaronol-treated astrocytes decreased the number of OPCs and increased the number of mature oligodendrocytes. These results suggest that α-asaronol can promote OPC differentiation and relieve dysmyelination by regulating glutamate levels via astrocyte PPARγ-GLT-1 signaling. Although whether α-asaronol binds to PPARγ directly or indirectly is not investigated here, this study still indicates that α-asaronol may be a promising small molecular drug for the treatment of myelin-related diseases.

Epilepsy is a common chronic neurological disorder disease, and there is an urgent need for the development of novel anticonvulsant drugs. In this study, the anticonvulsant activities and neurotoxicity of 12 cinnamic acid derivatives substituted by fluorine, chlorine, bromine, and trifluoromethyl groups were screened by the maximal electroshock seizure (MES) and rotarod tests (Tox). Three of the tested compounds (compounds 3, 6 and 12) showed better anticonvulsant effects and lower neurotoxicity. They showed respective median effective dose (ED₅₀) of 47.36, 75.72 and 70.65 mg/kg, and median toxic dose (TD₅₀) of them was greater than 500 mg/kg, providing better protective indices. Meanwhile, they showed a pentylenetetrazol (PTZ) ED₅₀ value of 245.2, >300 and 285.2 mg/kg in mice, respectively. Especially, the most active compound 3 displayed a prominent anticonvulsant profile and had lower toxicity. Therefore, the antiepileptic mechanism of 3 on glycosylation changes in chronic epilepsy in mice was further investigated by using glycomics techniques. Lectin microarrays results showed that epilepsy was closely related to abnormal glycosylation, and 3 could reverse the abnormal glycosylation in scPTZ-induced epilepsy in mice. This work can provide new ideas for future discovery of potential biomarkers for evaluation of antiepileptic drugs based on the precise alterations of glycopatterns in epilepsy.