Cellulose nanocrystals from marine algae Cladophora glomerata by using microwave-assisted extraction.

Algae of the order Cladophorales are the source of a unique nanocellulose with high crystallinity and a large aspect ratio, enabling broad surface modification. Cellulose nanocrystals (CNCs) are obtained via acid hydrolysis of nanocellulose, which is highly crystalline. However, the production of CNCs from Cladophorales algae is limited and still uses a conventional heating method. Thus, this study aimed to develop a microwave-assisted extraction (MAE) method for fast and efficient extraction of CNCs from Cladophora glomerata algae. Additionally, we replaced the use of hypochlorite with H2O2, which is more environmentally friendly, and compared the CNCs obtained from the conventional methods with our new method. The functional structure of CNCs was confirmed by Fourier-transform infrared spectroscopy. Single-step H2O2 bleaching with MAE yielded the smallest-sized CNCs. Our developed method resulted in the production of CNCs with a high crystallinity index, high thermal stability, and high purity of native cellulose. Additionally, none of the CNCs were toxic to primary normal human dermal fibroblasts. The properties of the isolated CNCs may make them useful materials in pharmaceutical and cosmetic formulations.

The comparison of the properties of nanocellulose isolated from colonial and solitary marine tunicates.

This is the first comparative of tunicate cellulose nanocrystalline (t-CNC) from colonial and solitary tunicates. The t-CNC from the colonial tunicate Eudistoma sp. (CL1) was compared with solitary tunicates Polycarpa reniformis (CL2) and Phallusia nigra (CL3). Tunicate samples were extracted by methanol. Residues from the methanol extraction were then subjected to further cellulose purification using pre-hydrolysis, kraft-cooking, bleaching, and sulfuric acid hydrolysis to yield t-CNC. The solitary tunicates yielded higher microfibril contents after the bleaching step but obtained similar t-CNC content to the colonial one after acid hydrolysis. The isolated t-CNC were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermalgravimetric analysis, and transmission electron microscopy. Both colonial and solitary tunicates yielded cellulose type I. The pure cellulose type I was successfully isolated from solitary tunicates whereas high inorganic impurities were observed in colonial tunicates. The isolate t-CNC showed high aspect ratios. The solitary and colonial tunicates provided t-CNC with crystallinity indexes over 97% and 35%, respectively. The crystalline size of t-CNCs ranged from 55-124 Å. The thermal stability of all isolated t-CNC was slightly decreased due to the sulfate functional groups gained after acid hydrolysis. We concluded that solitary tunicates were better than colonial tunicates as a source of t-CNC preparation.

In vitro evaluation of antioxidant and antibacterial activities of Eucheuma cottonii extract and its in vivo evaluation of the wound-healing activity in mice.

BACKGROUND: Eucheuma Cottonii is a type of red algae obtained from Sabah with main active component, sulfated polysaccharide or k-carrageenan. AIMS: The objective of this research was to evaluate the antioxidant, antibacterial and potential wound-healing properties in aqueous extraction of E cottonii in order to meet the increasing demand for halal and natural cosmeceutical products. METHODS AND RESULTS: Aqueous extract of E cottonii was investigated for active compounds by phytochemical screening and IR spectroscopy. Antioxidant activity was carried out using DPPH method, and the IC50 value was 1.99 mg/mL. Antibacterial activity was examined against Staphylococcus Aureus using Kirby-Bauer disk diffusion method and showed 10.03 ± 0.06 mm zone of inhibition, achieved by 200 mg/mL of extracts. A wound was made by skin excision of area around 100 mm2 on each mouse. Test group was treated with aqueous extract gel (10% w/w); meanwhile, the mice that were treated with honey acted as the positive control group and the untreated mice as negative control group. Results showed that the wound contraction rate inclined to aqueous extracts as compared to untreated group (P < .05). Percentage of wound healing for aqueous extracts and untreated group were 87.7% ± 2.0% and 57.6% ± 5.3%, respectively. CONCLUSION: Aqueous extract was found to be comparable to the honey in wound healing.

Development and skin penetration pathway evaluation of microemulsions for enhancing the dermal delivery of celecoxib.

This study aimed to develop a microemulsion using PEG-6 Caprylic/Capric Glycerides as a surfactant to enhance the dermal delivery of celecoxib. Confocal laser scanning microscopy (CLSM) using the colocalization technique was also used to investigate the skin penetration pathway of the microemulsion. The prepared microemulsion formulations were characterized in terms of size, surface charge, size distribution and type. The celecoxib-loaded microemulsion had particle sizes ranging from 48 to 214 nm with neutral charge and significantly increased the skin penetration of celecoxib. According to the CLSM study, the microemulsion might attach to any part of the skin before releasing the entrapped drug to penetrate the tissue. The transfollicular pathway might be the major skin penetration pathway for the microemulsion, whereas the intercellular and transcellular pathways are minor ones.

Design, synthesis, anti-lung cancer activity, and chemosensitization of tumor-selective MCACs based on ROS-mediated JNK pathway activation and NF-κB pathway inhibition.

EF24 and F35 both were effective monocarbonyl curcumin analogues (MCACs) with excellent anti-tumor activity, however, drug defect such as toxicity may limit their further development. To get anti-lung cancer drugs with high efficiency, low toxicity and chemosensitization, a series of analogues based on EF24 and F35 were designed and synthesized. A number of compounds were found to exhibit cytotoxic activities selectively towards lung cancer cells compared to normal cells. Among these compounds, 5B was considered as an optimal anti-tumor agent for lung cancer cells with IC50 values ranging from 1.0 to 1.7 µM, selectivity index (SI, as a logarithm of a ratio of IC50 value for normal and cancer cells) were all above 1.1, while the SI of EF24 and F35 were less than 0.8. Consistent with selectivity in vitro, 5B was observed to show lower toxicity in acute toxicity experiment than EF24 and F35 respectively. Further, 5B was found to exert anti-tumor effects through ROS-mediated activation of JNK pathway and inhibition of NF-κB pathway. 5B could significantly enhance the sensitivity of A549 cells to cisplatin or 5-Fu. These findings suggested that 5B was an effective and less toxic MCAC and provided a promising candidate for anti-tumor drugs.

Bromotyrosine-derived alkaloids from the Caribbean sponge Aplysina lacunosa.

Three new bromotyrosine-derived alkaloids 14-debromo-11-deoxyfistularin-3 (1), aplysinin A (2), and aplysinin B (3), together with 15 known compounds (4-18) were isolated from the sponge Aplysina lacunosa collected from Stirrup Cay, Bahamas. The structures of the isolated compounds were identified on the basis of MS and NMR data analysis. The (13)C NMR assignment of spirocyclohexadienylisoxazoline moieties of 1 and 2 were confirmed by an 1,1-ADEQUATE experiment. Compounds 1 and 2 showed a mild to moderate cytotoxic activities against KB-31 and FS4-LTM cell lines. Only aplysinin A (2) exhibited cytotoxicity against MCF-7 cells.

Kabiramide L, a new antiplasmodial trisoxazole macrolide from the sponge Pachastrissa nux.

An extensive search for the trisoxazole macrolides in the Thai specimen of the sponge Pachastrissa nux led to the isolation of a new kabiramide derivative, kabiramide L (1) and the previously reported kabiramide I (2). Both macrolides had a moderate antiplasmodial activity against Plasmodium falciparum K1 with IC50s of 2.6 and 4.5 µM, respectively. To date, P. nux has been the only known source of the trisoxazole macrolides bearing the 30-enone moiety. Both compounds were also added to the list of chemicals postulated to play a defensive role in the P. nux sponge.

Intracolonial allocation of trisoxazole macrolides in the sponge Pachastrissa nux.

Pachastrissa nux has two distinctive growth forms in one colony, i.e., the protruding gorgonian-shaped capitum and the substratum-attached irregular-shaped base. The sponge has the ability to allocate specifically its major secondary metabolites to the two parts in different levels. Using two cytotoxic trisoxazole macrolides, kabiramides C (2) and G (3), as chemical markers, it was found that the capitum accumulated higher contents of either or both compounds than did the base. However, there were neither inductive nor suppressive correlations among the allocation profiles of either compound in either part of the sponge. The allocation of kabiramides was a trade-off with the structural materials involved in reinforcing the strength of the sponge. To date, this is the second report that provides evidence of the specific allocation of bioactive metabolites in two distinctively different organ-like structures in a single sponge colony.

Kabiramides J and K, trisoxazole macrolides from the sponge Pachastrissa nux.

Three trisoxazole macrolides possessing a 30-α,ß-enone moiety, including the known kabiramide G (1) and the new kabiramides J (2) and K (3), were isolated from the sponge Pachastrissa nux, along with the previously reported kabiramides B (4), C (5), and D (6). To date, the enone moiety has been found to associate solely with the trisoxazole macrolides from P. nux. All of the isolated macrolides showed moderate to strong antimalarial and cytotoxic activities, except for 1, which possessed only potent cytotoxicity.