scholarly journals Biocatalytic Synthesis of a Novel Bioactive Ginsenoside Using UDP-Glycosyltransferase from Bacillus subtilis 168

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 289 ◽  
Author(s):  
Yumei Hu ◽  
Hao Li ◽  
Yingying Qu ◽  
Xiao Zhang ◽  
Juankun Zhang ◽  
...  

Ginsenoside Rg3 is a bioactive compound from Panax ginseng and exhibits diverse notable biological properties. Glycosylation catalyzed by uridine diphosphate-dependent glycosyltransferase (UGT) is the final biosynthetic step of ginsenoside Rg3 and determines its diverse pharmacological activities. In the present study, promiscuous UGT Bs-YjiC from Bacillus subtilis 168 was expressed in Escherichia coli and purified via one-step nickel chelate affinity chromatography. The in vitro glycosylation reaction demonstrated Bs-Yjic could selectively glycosylate the C12 hydroxyl group of ginsenoside Rg3 to synthesize an unnatural ginsenoside Rd12. Ginsenoside Rd12 was about 40-fold more water-soluble than that of ginsenoside Rg3 (90 μM). Furthermore, in vitro cytotoxicity of ginsenoside Rd12 against diverse cancer cells was much stronger than that of ginsenoside Rg3. Our studies report the UGT-catalyzed synthesis of unnatural ginsenoside Rd12 for the first time. Ginsenoside Rd12 with antiproliferative activity might be further exploited as a potential anticancer drug.

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 85 ◽  
Author(s):  
Truc Cong Ho ◽  
Jin-Seok Park ◽  
Sung-Yeoul Kim ◽  
Hoyeol Lee ◽  
Ju-Sop Lim ◽  
...  

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.


2018 ◽  
Vol 657 ◽  
pp. 78-88 ◽  
Author(s):  
Chinmayi R. Kaundinya ◽  
Handanahal S. Savithri ◽  
K. Krishnamurthy Rao ◽  
Petety V. Balaji

Author(s):  
Toshiro Fukushima ◽  
Hitomi Tanaka ◽  
Takeshi Yamamoto

SUMMARYThe aim of this study was to compare the results obtained from two in vitro cytotoxicity assays that depend upon different mechanisms/modes of action. The Neutral Red Uptake (NRU) assay is based on endocytotic activity whereas the Water Soluble Tetrazolium Salts (WST-1) assay is based on mitochondrial dehydrogenase activity. Both were investigated in light of their wide use and documented validation. The total particulate matter (TPM) and gas vapor phase (GVP) of main stream smoke derived from Kentucky reference cigarettes 3R4F and 10 test cigarettes made of 100% flue-cured or 100% Burley tobacco were individually applied to the two assays using CHO-K1 cells. In addition, cigarette smoke constituents and known cytotoxic agents, documented to affect specific endpoints, were evaluated within both assays. Although the NRU assay was primarily more sensitive than the WST-1 assay, both assays provided comparable results in terms of the rank order for the cytotoxicity of cigarette smoke samples. In addressing the cytotoxicity of constituents in cigarette smoke, acrolein, hydroquinone and catechol gave clear dose-related decreases in cell viability (an end point common in both assays). Moreover, enzyme inhibitors of the mitochondrial respiratory chain and chemicals causing membrane disruption also showed similar responses regardless of the specific endpoint addressed within the cytotoxicity assay. In conclusion, results from the NRU and WST-1 assay are comparable therefore indicating results were independent of the different assay detection mechanisms/modes of action. [Beitr. Tabakforsch. Int. 26 (2014) 98-108]


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2100
Author(s):  
Monika Richert ◽  
Renata Mikstacka ◽  
Mariusz Walczyk ◽  
Marcin Janusz Cieślak ◽  
Julia Kaźmierczak-Barańska ◽  
...  

Gold(I) complexes with phosphine ligands—[Au(TrippyPhos)Cl] (1) (TrippyPhos = 1-[2-[bis(tert-butyl)phosphino]phenyl]-3,5-diphenyl-1H-pyrazole), [Au(BippyPhos)Cl]0.5CH2Cl2 (2) (BippyPhos = 5-(di-tert-butylphosphino)-1′, 3′, 5′-triphenyl-1′H-[1,4′]bipyrazole), and [Au(meCgPPh)Cl] (3) (meCgPPh = 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane—were investigated as types of bioactive gold metallodrugs. Complexes (1)–(3) were characterized using IR, 1H, 13C, 31P NMR spectroscopy, elemental analysis and mass spectrometry (FAB-MS). Complexes of (1) and (2) exhibited substantial in vitro cytotoxicity (IC50 = 0.5–7.0 μM) against both the cisplatin-sensitive and -resistant variants of the A2780 human ovarian carcinoma cell line, as well as against the A549 human lung carcinoma, K562 chronic myelogenous leukemia, and HeLa (human cervix carcinoma) cells. However, among the compounds studied, complex (2) showed the most promising biological properties: the highest stability in biologically relevant media, selectivity towards cancer cells over the non-cancer cells (HUVEC, human umbilical vein endothelial cells), and the highest inhibitory effect on cytosolic NADPH-dependent reductases in A2780 and A2780cis cells among the gold complexes under analysis.


2020 ◽  
Vol 7 (1) ◽  
pp. 20 ◽  
Author(s):  
Suresh Thangudu ◽  
Poliraju Kalluru ◽  
Raviraj Vankayala

Fluorescent probes offer great potential to identify and treat surgical tumors by clinicians. To this end, several molecular probes were examined as in vitro and in vivo bioimaging probes. However, due to their ultra-low extinction coefficients as well as photobleaching problems, conventional molecular probes limit its practical utility. To address the above mentioned challenges, metal nanoclusters (MNCs) can serve as an excellent alternative with many unique features such as higher molar extinction coefficients/light absorbing capabilities, good photostability and appreciable fluorescence quantum yields. Herein, we reported a green synthesis of water soluble palladium nanoclusters (Pd NCs) and characterized them by using various spectroscopic and microscopic characterization techniques. These nanoclusters showed excellent photophysical properties with the characteristic emission peak centered at 500 nm under 420 nm photoexcitation wavelength. In vitro cytotoxicity studies in human cervical cancer cells (HeLa) cells reveal that Pd NCs exhibited good biocompatibility with an IC50 value of >100 µg/mL and also showed excellent co-localization and distribution throughout the cytoplasm region with a significant fraction translocating into cell nucleus. We foresee that Pd NCs will carry huge potential to serve as a new generation bioimaging nanoprobe owing to its smaller size, minimal cytotoxicity, nucleus translocation capability and good cell labelling properties.


2009 ◽  
Vol 610-613 ◽  
pp. 1011-1016 ◽  
Author(s):  
Yan Mei Chen ◽  
Ting Fei Xi ◽  
Yu Dong Zheng ◽  
Yi Zao Wan

The nanocomposite of nano-hydroxyapatite/bacterial cellulose (nHA/BC) obtained by depositing in simulated body fluid (SBF), incorporating their excellent mechanical and biological properties, is expected to have potential applications in bone tissue engineering. However, the biological response evaluation of biomaterials is required to provide useful information to improve their design and application. In this article, the in vitro cytotoxicity of composites nHA/BC as well as its degradation residues was studied. Scanning electron microscopy (SEM) was used to observe the morphology of original materials and their degradation residues. The degree of degradation was evalued by measuring the concentration of reducing sugar (glucose) by ultraviolet spectrophotometer. Bone-forming osteoblasts (OB) and infinite culture cell line L929 fibroblasts were used to measure the cytotocixity of materials with MTT assay. Both kinds of cells in infusion proliferate greatly in a normal form and their relative growth rate (RGR) exceeds by 75%, which shows the cytotoxicity of materials is graded as 0~1, according to the national standard. Nevertheless, bone-forming OB cells, as a kind of target cells, are more susceptive on the cytotoxicity than infinite culture fibroblast cells L929. The results suggest the nanocomposite of nHA/BC without cytotoxicity is greatly promising as a kind of scaffold materials for bone tissue engineering and tissue functional cells are more suited to evaluate the cytotoxicity of biomedical materials.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2081-2081 ◽  
Author(s):  
J. Lancet ◽  
I. Gojo ◽  
M. Baer ◽  
M. Burton ◽  
M. Klein ◽  
...  

2081 Background: Disruption of Hsp90-client protein heterocomplexes leads to degradation of a variety of oncoproteins. KOS-1022, an Hsp90 inhibitor and water-soluble geldanamycin derivative, is in trials in patients with solid tumors. Compared to a prior geldanamycin derivative (17-AAG), KOS-1022 is ∼3–5 fold more potent (comparing in vitro cytotoxicity or the MTD in toxicology studies on the same schedule). Primary study objectives: establish safety and MTD of KOS-1022 in patients with advanced hematologic malignancies; characterize PK and PD. Methods: Escalating doses of KOS-1022 are given IV over 1 h twice weekly for 2 out of 3 weeks. Plasma KOS-1022 concentrations (1st and 4th infusion, Cycle 1) are quantitated by LC/MS/MS. Pre and on-study CD34+ bone marrow and peripheral blasts undergo flow cytometry to quantify Hsp70/90, pAKT/total AKT, markers of apoptosis and proliferation. Response in AML pts used IWG criteria. Results: 13 pts have been enrolled at doses of 8 (n=4), 16 (n=6), 24 (n=1) and 32 mg/m2 (n=2). All were AML (except 1 CML). Most (n=11) patients had 2–3 prior induction regimens. DLT was seen in 2 pts at 32 mg/m2 (acute myocardial infarction and elevation of troponin). Both patients had significant co-morbidity, including (1) prior myocardial infarction and (2) progressive AML with a similar troponin elevation during induction chemotherapy prior to study. Common drug-related toxicities (all Grade 1–2): fatigue, nausea, diarrhea and arthralgias. From 8 to 32 mg/m2, approximately linear PK was observed. Mean terminal half-lives varied from 13.0–31.2 hours. Day 1 clearance for 8, 16 and 32 mg/m2 was 5.6, 9.7 and 10.8 L/hr/m2; mean Vz (L/m2) for these groups were 238, 433 and 489. Although pre-infusion drug was quantifiable on Day 11 in most patients, Day 11/Day 1 AUC0–25h ratio was 0.96. Activity in AML: 2 CRi and 1 SD x 9 cycles were observed. Comparing BMAs taken at Day 8 and Day 15 to baseline: decreased Hsp90 (41% to 13%), increased Hsp70 (8% to 84%) with decreased pAKT (Ser), pAKT (Thr) and total AKT in CD34+ cells. Conclusions: KOS-1022 appears to be well tolerated, with preliminary signs of clinical and biologic activity in refractory leukemia. MTD has not been defined. Plasma PK is linear over this dose range. [Table: see text]


2017 ◽  
Vol 2 (28) ◽  
pp. 8721-8725 ◽  
Author(s):  
Sergey N. Britvin ◽  
Andrey M. Rumyantsev ◽  
Anna A. Silyutina ◽  
Marina V. Padkina

2004 ◽  
Vol 70 (6) ◽  
pp. 3521-3527 ◽  
Author(s):  
Min Ye ◽  
Guiqin Qu ◽  
Hongzhu Guo ◽  
Dean Guo

ABSTRACT Biotransformation of natural products has great potential for producing new drugs and could provide in vitro models of mammalian metabolism. Microbial transformation of the cytotoxic steroid cinobufagin was investigated. Cinobufagin could be specifically hydroxylated at the 12β-position by the fungus Alternaria alternata. Six products from a scaled-up fermentation were obtained by silica gel column chromatography and reversed-phase liquid chromatography and were identified as 12β-hydroxyl cinobufagin, 12β-hydroxyl desacetylcinobufagin, 3-oxo-12β-hydroxyl cinobufagin, 3-oxo-12β-hydroxyl desacetylcinobufagin, 12-oxo-cinobufagin, and 3-oxo-12α-hydroxyl cinobufagin. The last five products are new compounds. 12β-Hydroxylation of cinobufagin by A. alternata is a fast catalytic reaction and was complete within 8 h of growth with the substrate. This reaction was followed by dehydrogenation of the 3-hydroxyl group and then deacetylation at C-16. Hydroxylation at C-12β also was the first step in the metabolism of cinobufagin by a variety of fungal strains. In vitro cytotoxicity assays suggest that 12β-hydroxyl cinobufagin and 3-oxo-12α-hydroxyl cinobufagin exhibit somewhat decreased but still significant cytotoxic activities. The 12β-hydroxylated bufadienolides produced by microbial transformation are difficult to obtain by chemical synthesis.


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