In vitro transfection efficiencies of T-shaped spermine-based cationic lipids with identical and nonidentical tails under high serum conditions.

T-shaped spermine-based cationic lipids with identical and nonidentical hydrophobic tails having variable carbon lengths (from C10 to C18) were designed and synthesized. These lipids were characterized, and their structure-activity relationships were determined for DNA binding and transfection ability of these compounds when formulated as cationic liposomes. These liposomes were then applied as non-viral vectors to transfect HEK293T, HeLa, PC3, H460, HepG2, and Calu'3 cell lines with plasmid DNA encoding the green fluorescent protein. ST9, ST12 and ST13 with nonidentical tails could deliver DNA into HEK293T cells up to 60% under serum-free conditions. The lipid ST15 bearing nonidentical tails was found to be a potent gene transfer agent under 40% serum conditions in HEK293T and HeLa cells. Besides their low cytotoxicity, these lipoplexes also exhibited greater transfection efficiency than the commercially available transfection agent, Lipofectamine 3000.

N'-(3-Aminopropyl)-N-(3'-(carbamoyl cholesteryl) propyl)-glycine amide liposomes for delivery of pTRAIL-EGFP.

In this study, N'-(3-aminopropyl)-N-(3'-(carbamoyl cholesteryl) propyl)-glycine amide (A) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE, D) (AD) liposomes were synthesised at molar ratios of 50:25 (AD5025), 50:50 (AD5050) and 50:75 (AD5075) and complexed with plasmid, pTRAIL-EGFP. AD liposome/pTRAIL-EGFP were evaluated for their complex ability, particle size, polydispersity index, zeta potential, expression of pTRAIL-EGFP, cytotoxicity, cell growth inhibition and apoptosis induction in KB cells. AD liposomes complexed completely with pTRAIL-EGFP at AD liposome/DNA ratios of above 4.5/1. The particle size of AD liposome/pTRAIL-EGFP ranged from 180 ± 8 to 1,072 ± 657 nm depending on the proportion of lipid composition and liposome/DNA ratio. The extent of gene expression of pTRAIL-EGFP via AD liposome/pTRAIL-EGFP was significantly higher than that of the cells treated with pTRAIL-EGFP and depended on the AD liposome/DNA ratio. Cytotoxicity of AD liposomes was dependent on A and D molar ratio. Cell growth inhibition of AD liposome/pTRAIL-EGFP was significantly higher than that of the cells treated with pTRAIL-EGFP. The amount of late apoptotic and dead cells of AD liposome/pTRAIL-EGFP was significantly higher than that of cells treated with pTRAIL-EGFP. From this study that one can conclude that AD liposomes can carry and deliver pTRAIL-EGFP into KB cells resulting in cell growth inhibition and cell death.

Enhancing Anticancer Potency of a 13-Substituted Berberine Derivative with Cationic Liposomes.

Cationic liposomal formulations of the telomeric G-quadruplex stabilizing ligand, 13-(2-naphthylmethoxy)berberine bromide (1), have been developed with the purpose of delivering 1 into the nucleus of cancer cells for potential telomere targeting. Berberine derivative 1 was encapsulated in various cationic lipids 2-4 by the thin film evaporation method; these lipids are cationic after amine protonation. The most appropriate liposomal berberine formulation was that of 1 and the cholesterol derived cationic lipid 4 in a weight ratio of 1 : 20 with 76.5% encapsulation efficiency of 1. Cellular uptake studies in the HeLa and HT-29 cancer cells lines showed that the liposomal berberine derivative uptake in the cells was higher and more stable than for berberine derivative 1 alone while free 1 was completely decomposed in the cells within 60 min exposure to the cells. Anticancer activity of the liposomal berberine derivative 1 based on 4 was greater than that for the free berberine derivative 1 in the MCF-7, HeLa and HT-29 cell line by 2.3-, 4.9- and 5.3-fold, respectively, and also, interestingly, superior to the anticancer drug doxorubicin against the HT29 cancer cell line.

Synthesis and in vitro transfection efficiency of spermine-based cationic lipids with different central core structures and lipophilic tails.

Twelve spermine-based cationic lipids with four different central core structures (di(oxyethyl)amino, di(oxyethyl)amino carboxy, 3-amino-1,2-dioxypropyl and 2-amino-1,3-dioxypropyl) and three hydrophobic tails (lauric acid, myristic acid and palmitic acid) were synthesized. The liposomes containing lipids and DOPE showed moderate to good in vitro DNA delivery into HeLa cells. GFP expression experiments revealed that liposomes composed of lipids with 3-amino-1,2-dioxypropyl as a central core structure exhibited highest transfection efficiency under serum-free condition. Whereas, lipid with 2-amino-1,3-dioxypropyl core structure showed highest transfection under 10% serum condition. Moreover, the liposomes and lipoplexes composted of these cationic lipids exhibited low cytotoxicity.

Synergistic effect of cationic lipids with different polarheads, central core structures and hydrophobic tails on gene transfection efficiency.

Lipid-mediated delivery of DNA into cells holds great promise both for gene therapy and basic research applications. The primary approach to improving transfection efficiency is the design and synthesis of novel cationic lipids. Alternatively, using the synergistic effect of different cationic mixtures can provide another approach to increasing transfection efficiency. This paper describes the synergistic effect of lipids with different polarheads, central core structures and hydrophobic tails. The enhancement of cellular transfection into HEK293 cells was observed by combining two lipids having aminoglycerol and di(hydroxylethyl)amino core structures at a 1 : 1 weight ratio. Additionally, the liposome formation of these lipids with the helper lipid, 1,2-dioleoyl-propyl-3-phosphatidylethanolamine (DOPE), at the weight ratio of 1 : 1 can provide higher transfection efficiency into HEK293, MCF-7 and HeLa cells than Lipofectamine™ 2000. Our finding indicated that cationic liposomes comprised of a mixture of lipids with different polarheads, central core structures and hydrophobic tails should be very promising in liposome-mediated gene delivery in vitro and in vivo.

Novel racemic tetrahydrocurcuminoid dihydropyrimidinone analogues as potent acetylcholinesterase inhibitors.

The synthesis of racemic tetrahydrocurcumin- (THC-), tetrahydrodemethoxycurcumin- (THDC-) and tetrahydrobisdemethoxycurcumin- (THBDC-) dihydropyrimidinone (DHPM) analogues was achieved by utilizing the multi-component Biginelli reaction in the presence of copper sulphate as a catalyst. The evaluation of acetylcholinesterase inhibitors for Alzheimer's disease of these compounds showed that they exhibited higher inhibitory activity than their parent analogues. THBDC-DHPM demonstrated the most potent inhibitory activity with an IC50 value of 1.34±0.03µM which was more active than the approved drug galanthamine (IC50=1.45±0.04µM).

A new pyrrole alkaloid from the roots of Cissampelos pareira.

Phytochemical investigation of the roots of Cissampelos pareira Linn. led to the isolation of one new pyrrole alkaloid, cissampeline (1), together with ten known alkaloids, (-)-curine (2), (-)-cyclanoline (3), (+)-tetrandrine (4), (+)-obaberine (5), (+)-obamegine (6), (-)-oblongine (7), (+)-homoaromoline (8), (-)-nor-N׳-chondrocurine (9), trans-N-feruloyltyramine (10) and (+)-coclaurine (11). Their structures were elucidated by extensive NMR and MS spectroscopic analyses. Interestingly, compound 1 represents the first example of pyrrole alkaloid found in the genus Cissampelos. Moreover, compounds 5-11 were isolated for the first time from this genus. Among them, compound 6 showed the highest anti-acetylcholinesterase activity with an IC50 value of 3.26 µM, whereas compound 8 displayed the most potent cytotoxicity against human colon cancer (HT29) cells with an IC50 value of 7.89 µM.

A new ent-abietane lactone from Glycosmis pentaphylla.

A new ent-abietane lactone, 3-oxojolkinolide A (1), together with 16 known compounds, helioscopinolide E (2), helioscopinolide A (3), 3-methyl-9H-carbazole (4), carbalexin (5), carbalexin B (6), glycaborinine (7), arborinine (8), 1H-indole-3-carbaldehyde (9), glycoamide A (10), glycoamide B (11), 2-(N-methyl-2-phenylacetamido)benzoic acid (12), 2-(methylamine)-methylbenzoate (13), fraxidin (14), scopoletin (15), (-)-syringaresinol (16) and ferulic acid (17) were isolated from Glycosmis pentaphylla. The structures of these compounds were elucidated using spectroscopic techniques such as NMR and MS. Among them, compounds 1-3, 9 and 12-17 were isolated from the genus Glycosmis for the first time.

Synthesis of bis, tris and tetra(dihydrocaffeoyl)polyamine conjugates as antibacterial agents against VRSA.

Bis, tris and tetra(dihydrocaffeoyl)polyamine conjugates were synthesized using solid phase synthesis technique. These compounds were screened for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) (11 strains) and vancomycin-resistant S. aureus (VRSA) (4 strains). Bis, tris and tetra(dihydrocaffeoyl)polyamine analogues showed antibacterial activity against VRSA which were better than the reference drugs, vancomycin. Tetra(dihydrocaffeoyl)polyamine conjugate exhibited the highest activity. These compounds showed no cytotoxicity against vero cells.

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark of Ziziphus cambodiana.

Six new 14-membered ring cyclopeptide alkaloids, cambodines A-F (1-6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Ziziphus cambodiana Pierre. Their structures and configurations were established based on 1D and 2D NMR, HRMS, ECD, and X-ray crystallographic data. Compounds 1 and 3 are rare 5(14)-type cyclopeptide alkaloids that possess an imidazolidin-4-one ring in the terminal unit. The cyclopeptides were tested for their in vitro antiplasmodial, antitubercular, and cytotoxic effects against three cancer cell lines. Compound 3 showed significant antiplasmodial activity against the malarial parasite Plasmodium falciparum, with an IC50 value of 6.09 µM.

Cholesterol-based cationic liposome increases dsRNA protection of yellow head virus infection in Penaeus vannamei.

Protection of shrimp from yellow head virus (YHV) infection has been demonstrated by injection and oral delivery of dsRNA-YHV protease gene (dsYHV) or shrimp endogenous gene (dsRab7). However, to achieve complete viral suppression and to prolong dsRNA activity, the development of an effective dsRNA delivery system is required. In this study, four cationic liposomes were synthesized and tested for their ability to increase dsRNA efficiency. The results demonstrated that entrapping dsYHV in a cholesterol-based cationic liposome gave the best protection against YHV infection when compared with other cationic lipids. The cholesterol-based cationic liposome-dsYHV (Chol-dsYHV) complex conferred YHV protection in a dose-dependent manner. Injection with Chol-dsYHV at 0.05µg dsYHV/g shrimp could give comparable level of YHV protection to the injection with 1.25µg naked dsYHV/g shrimp. The shrimp injected with Chol- dsYHV at 1.25µg dsRNA/g shrimp showed only 50% mortality at 60days post injection whereas the naked dsYHV at the same concentration gave 90% mortality. Thus, the liposome-entrapped dsYHV could lower an effective dsRNA concentration in viral protection and prolong dsRNA activity. In addition, encapsulating dsRab7 in the cholesterol-based cationic liposome could protect the dsRab7 from enzymatic digestion, and continuous feeding the shrimp with the diet formulated with the liposome-entrapped dsRab7 for 4days in the total of 960µg dsRab7/g shrimp could enhance YHV protection efficiency compared with the naked dsRab7. Our studies reveal that cholesterol-based cationic liposome is a promising dsRNA carrier to enhance dsRNA efficiency in both injection and oral delivery systems.

A New 3'-Prenyloxypsoralen from the Raw Fruits of Aegle marmelos and its Cytotoxic Activity.

One new furanocoumarin, 3'-prenyloxypsoralen (1), and two known furanocoumarins, imperatorin (2) and xanthotoxin (3) were isolated from the raw fruits of Aegle marmelos. The structures of the isolated coumarins were confirmed by spectroscopic evidence. Compound 1 exhibited moderate cytotoxic activity against HEK293, HeLa, MCF7, and HT29 cell lines with IC50 values of 31.2, 44.8, 36.3, and > 50.0 µg/mL, respectively.

Solid-phase synthesis and antibacterial activity of hydroxycinnamic acid amides and analogues against methicillin-resistant Staphylococcus aureus and vancomycin-resistant S. aureus.

A library of hydroxycinnamic acid amides (HCAAs) and analogues were synthesized using solid-phase synthesis technique. These compounds were screened for antibacterial against methicillin-resistant Staphylococcus aureus (MRSA) (11 strains) and vancomycin-resistant S. aureus (VRSA) (4 strains). Dihydrocaffeoyl analogues showed activity against VRSA which were better than the reference drugs, vancomycin and oxacillin. These compounds also exhibited antibacterial activity against MRSA, which were more potent than oxacillin.