Natural Distribution, Structures, Synthesis, and Bioactivity of Hasubanan Alkaloids.

Hasubanan alkaloids represent a distinct class of alkaloids bearing a structural resemblance to morphine, predominantly found in herbals of the Stephania genus. Their intriguing molecular architecture and potential analgesic properties have captured the interest of medicinal chemists worldwide. This review meticulously examines the natural distribution, structural characteristics, biosynthetic pathways, synthetic methodologies, and biological activities of hasubanans.

Chemical profile of the roots of Clausena lansium and their inhibitory effects of the over-activation in BV-2 microglial cells.

From the 95% ethanol aqueous extract of the roots of Clausena lansium, six previously undescribed alkaloids (1, 2a, 2b, 15, 24a, 24b), a pair of prenylated phenylpropenols (26a, 26b), two coumarins (27, 28), and two undescribed sesquiterpenes (37, 38) were isolated and identified using spectroscopic and electron circular dichroism data, together with thirty-two known compounds. The absolute configurations of three alkaloids (3a, 3b, 4a) were determined for the first time. In vitro assay showed that alkaloids 7, 10, 12, 19, and furanocoumarins 34, 35 displayed inhibitory effects on the production of nitric oxide in lipopolysaccharide (LPS)-induced BV-2 microglial cells, which were stronger than that of the minocycline (positive control). RT-PCR results indicated that indizoline (7) could inhibit the expression of pro-inflammatory factors (IL-1ß, TNF-α, and IL-6) in LPS-treated BV-2 cells.

Seconds Timescale Synthesis of Highly Stretchable Antibacterial Hydrogel for Skin Wound Closure and Epidermal Strain Sensor.

Effective wound healing is critical for patient care, and the development of novel wound dressing materials that promote healing, prevent infection, and are user-friendly is of great importance, particularly in the context of point-of-care testing (POCT). This study reports the synthesis of a hydrogel material that can be produced in less than 10 s and possesses antibacterial activity against both gram-negative and gram-positive microorganisms, as well as the ability to inhibit the growth of eukaryotic cells, such as yeast. The hydrogel is formed wholly based on covalent-like hydrogen bonding interactions and exhibits excellent mechanical properties, with the ability to stretch up to more than 600% of its initial length. Furthermore, the hydrogel demonstrates ultra-fast self-healing properties, with fractures capable of being repaired within 10 s. This hydrogel can promote skin wound healing, with the added advantage of functioning as a strain sensor that generates an electrical signal in response to physical deformation. The strain sensor composed of a rubber shell realizes fast and responsive strain sensing. The findings suggest that this hydrogel has promising applications in the field of POCT for wound care, providing a new avenue for improved patient outcomes.

Study on Chemical Components from Derris taiwaniana and Their Lung Epithelial Cell Protect Effects.

The ethanol extract of roots of Derris taiwaniana gave two undescribed compounds, 3,3'-dimethoxy-5'-hydroxystilbene-4-O-ß-apiofuranosyl-(1→6)-ß-D-glucopyranoside (1) and 4',5-dihydroxy-3'-methoxyisoflavone-7-O-ß-apiofuranosyl-(1→6)-ß-D-glucopyranoside (2), along with thirty known components. Among them, compounds 14, 16-17, 23, 26-32 were isolated from this genus for the first time. Their structures were established based on physico-chemical properties and spectroscopic data, the lung epithelial cell protective effects were evaluated using NNK-induced MLE-12 cells. Among them, 2α,3α-epoxy-5,7,3',4'-tetrahydroxyflavan-(4ß-8-catechin) (30) showed the best significant protective effect, speculated to be the key component of D. taiwaniana that plays a protective role in lung epithelial cells.

Online quantitative substrate, product, and cell concentration in citric acid fermentation using near-infrared spectroscopy combined with chemometrics.

As a mature platform compound, citric acid (CA) is mainly produced by Aspergillus niger (A. niger) through submerged fermentation. However, the CA fermentation process is still regulated based on experience and limited offline data, so real-time monitoring and intelligent precise control of the fermentation process cannot be carried out. In this study, near-infrared (NIR) spectroscopy combined with different chemometrics methods was used to quantify the substrate, product, and cell concentration of CA fermentation online. The predictive performance of total sugar (TS), CA, and dry cell weight (DCW) concentrations were compared between traditional partial least squares (PLS) and intelligent stacked auto-encoder (SAE) modeling methods. Theresults showed that both PLS and SAE models had good performance in predicting TS and CA. The performance, accuracy, and precision of the PLS models are slightly better than those of the SAE models in predicting TS and CA. SAE model was superior to the PLS model in predicting DCW concentration. The SAE modeling method has advantages in predicting the concentration of complex components. In this study, the multi-parameter online prediction was realized in the complex system of CA fermentation, which provided the basis for real-time intelligent control of the fermentation process.

Effect of citric acid residue and short-chain fatty acids on fermentation quality and aerobic stability of lucerne ensiled with lactic acid bacteria inoculants.

The experiment aimed to compare the effects of citric acid residue (CAR) to that of three commonly used short-chain fatty acids on the fermentation quality, aerobic stability and structural carbohydrate degradation of lucerne ensiled with lactic acid bacteria (LAB) inoculants. Fresh lucerne was ensiled with distilled water (control), LAB inoculant (L), CAR + LAB inoculant (CL), formic acid + LAB inoculant (FL), acetic acid + LAB inoculant (AL) and propanoic acid + LAB inoculant (PL) for 50 days. Chemical composition and microbial populations were determined after ensiling. The residual silages ensiled for 50 days were evaluated for aerobic stability. Compared with control, CL, FL, AL and PL treatments significantly (p < 0.05) decreased pH, ammonia nitrogen (NH3 -N) and butyric acid contents and increased lactic acid, acetic acid and propionic acid contents. Among them, CL silages had the lowest pH, dry matter and water-soluble carbohydrate (WSC) content, whereas the population of LAB and the lactic acid contents were highest. Besides, CL outperformed in enhancing fibre degradation, CL silages significantly decreased (p < 0.05) neutral detergent fibre, acid detergent fibre, hemicellulose and cellulose contents compared with control and had the highest Flieg's point. All treated-silages improved the aerobic stability compared with control, of which L improved 32 h, whereas CL, FL, AL and PL improved 46, 20, 46, >64 h, respectively. Applying a combination of CAR and LAB inoculant improved the fermentation quality and structural carbohydrate degradation of lucerne silage and had a similar effect on aerobic stability compared with other three short-chain fatty acids. The CAR had a comparable effect on enhancing the fermentation quality compared with three short-chain fatty acids. Thus, the combination of CAR and LAB inoculant might be used as an ideal additive for lucerne silage making with low WSC and high moisture content.

Pellet-dispersion strategy to simplify the seed cultivation of Aspergillus niger and optimize citric acid production.

Citric acid (CA) as an extremely important platform compound has attracted intense attention due to wide applications and huge markets. Here, we proposed a novel method, using pellet inoculation to replace spores, and constructed the seed recycling cultivation process, effectively avoided the longtime (spore preparation 30 days) of seed culture (including spores germination 12 h) in the traditional batch-fermentation. On this basis, using pellet-dispersion strategy, the bottleneck caused by the mycelium structure was overcome, with the seed restoring high cell-viability with CA titer (11.0 g/L) even in the eighth batch compared to that in the control (4.6 g/L). The optimum morphology of these recycling cultured seeds for CA production was dispersed pattern rather than pellets. And the CA production was 130.5 g/L on average in 5 L five-conjoined-fermenters recycling eight batches, especially increasing 3.1 g/L compared with the control. To our knowledge, this is the first that reported the application of these strategies in effective production of CA. Our fermentation strategies not only significantly enhanced CA productivity, but also severed as a promising stepping-stone for other fermentations dominated with the filamentous fungi.