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Green marine macroalgae, particularly Ulva lactuca, is an essential constituent of the cuisines in many Asian countries. The present work aims to separate a bioactive pyrone attached benzochromene analogue, named as ulvapyrone from the organic extract of U. lactuca, followed by its structural characterisation as 2-{(6a′-hydroxyethyl-4′-methyltetrahydro-2H-pyran-2′-one)-6′-yl}-4-methyl-7-ethylacetate-8-hydroxy-7, 8-dihydrobenzo [de]chromene. Ulvapyrone exhibited prospective inhibition property against arachidonate 5-lipoxygenase (IC50 ∼1 mg mL−1) comparable to that demonstrated by ibuprofen (IC50 0.9 mg mL−1), which connoted its anti-inflammatory activity. The studied benzochromene exhibited promising antioxidant potential (IC50 0.5–0.6 mg mL−1), which further reinforced its attenuation property against 5-lipoxygenase. Bioactivities of ulvapyrone were linearly correlated with electronic parameter (topological polar surface area ∼102) along with less binding energy (–8.22 kcal mol−1) with the allosteric site of 5-lipoxygenase. In silico predictions of physicochemical parameters along with absorption, distribution, metabolism and excretion could recognise the acceptable oral bioavailability of ulvapyrone. [ABSTRACT FROM AUTHOR]

Chemical analysis of the organic extract from intertidal brown seaweed Sargassum ilicifolium (family Sargassaceae) characterised an undescribed xenicane-type diterpenoid sargilicixenicane, elucidated as 3-(17-hydroxy-14-methylhept-13-en-10-yl)-6-methylhexahydro-1H-cyclonona[c]furan-4,19-diyl diacetate (compound 1). The studied compound exhibited prospective free radical quenching potential (IC50 1.2-1.4 mM) in comparison with commercial antioxidant (α-tocopherol, IC50 > 1.40 mM). Attenuation property of sargilicixenicane against pro-inflammatory enzyme, 5-lipoxygenase (IC50 4.70 mM) was comparable with that displayed by the non-steroidal anti-inflammatory agent ibuprofen (IC50 4.51 mM). Greater selectivity index displayed by the studied xenicane-type diterpenoid (1.42) than that exhibited by ibuprofen (0.44) recognised the selective attenuation potential of the former against the inducible cyclooxygenase-2 and 5-lipoxygenase enzymes. Higher electronic parameters (topological polar surface area, 82.06) and balanced hydrophobic-hydrophilic property (octanol-water partition coefficient 2.94) coupled with docking score (-11.17 kcal mol−1) and lower binding energy (-9.61 kcal mol−1) with the active site of 5-lipoxygenase supported the significant anti-inflammatory properties of the studied xenicane-type diterpenoid. [ABSTRACT FROM AUTHOR]

The organic extract of Turbinaria conoides, a brown seaweed harvested from the Gulf of Manner region of Indian peninsular was chromatographically fractionated to yield three substituted 2H-pyranoids, namely methyl-21-yl-[5′, 6′- dihydro-5′-yl-{54-(4-hydroxybenzoyl)-oxy-(52-methylbutyl)}-3′-methyl-2H-pyran]-21-methyl butanoate (1), 11-[(3′, 6′-dihydro-4′-methyl-2′-oxo-2H-pyran-3′-yl)methyl]-10-methylhexyl benzoate (2), and [6-ethyl-3,4-dimethyl-(tetrahydro-2′, 2′, 6′-trimethyl-2H-pyran-3′-yl)-2,5-cycloheptadiene]-1-propanoate (3). The compounds 1 and 2 bearing 2H-pyranyl-4-hydroxybenzoyl and 2H-pyranyl-10-methylhexylbenzoate moieties exhibited potential antioxidant activities (IC50 0.54-0.69 mg mL−1) as commercial antioxidant (α-tocopherol IC50 0.63-0.73 mg mL−1). Likewise, potential bioactivity of the 2H-pyran derivative, 1 against 5-lipoxygenase (IC50 ∼ 1 mg mL−1) along with higher index of selectivity (COX-1 inhibitoryIC50/COX-2 inhibitoryIC50 1.88) indicated their selective anti-inflammatory properties against inducible inflammatory mediators than that displayed by commercially available non-steroidal anti-inflammatory drug (ibuprofen, 0.44). Structure activity relationship analysis of the studied compounds showed that the antioxidative and anti-inflammatory properties were directly proportional to their electronic properties. The previously undescribed 2H-pyranoids might constitute as potential antioxidative and anti-inflammatory pharmacophores for medicinal applications. [ABSTRACT FROM AUTHOR]

Sugar-based low-molecular-weight gelators (LMWGs) have been used for various applications for a long time. Herein, structurally simple, ester-protected arabinosides are reported as low-molecular-weight organogelators (LMOGs) that are able to gel aromatic solvents, as well as petrol and diesel. Studies on the mechanical strength of the gels, through detailed rheological experiments, indicate that gels from the 1,2-dibenzoylated arabinose gelator possess better mechanical properties than those from the 1,2-diacetylated gelator. These results are interpreted in terms of the tendency of the former to form fibers with comparatively lower diameter than those of the latter, based on detailed field-emission SEM and AFM studies. Investigations of the interactions responsible for the self-assembly of gelators through IR spectroscopy and wide-angle X-ray scattering reveal that the primary interactions responsible are hydrogen bonds between the hydroxyl groups and ester C=O, which is absent in the solid state of the gelators. In addition, π interactions present in the 1,2-dibenzoylated derivative result in a more regular arrangement, which, in turn, leads to better mechanical properties of the gels compared with those of the 1,2-diacetylated gelator. [ABSTRACT FROM AUTHOR]

The slipper oyster Magallana bilineata (Ostreidae) is considered as culinary delicacy among marine bivalves, and a sulphated glycosaminoglycan, 4,6-O-SO 3 - β -(1→3)-GalNAc p (unit A) and β -(1→4)-GlcA p (unit B) as principle structural motif containing laterally branched 4-O-SO 3 - β -glucopyranose (unit C) (MBP-3) was isolated from this species. Nuclear magnetic resonance (NMR), Fourier transform infra-red (FTIR), and mass spectroscopy techniques were used to characterise MBP-3. MBP-3 exhibited anti-inflammatory activities against inflammatory 5-lipoxygenase (IC 50 0.11 mg mL -1 ) and cyclooxygenase-2 (IC 50 0.12 mg mL -1 ) enzymes. MBP-3 (at 100 μg mL -1 ) showed effective downregulation against pro-inflammatory cytokines generation, namely interleukins-6, 1 β , (IL-6, 1 β ) (1-1.7 pg mL -1 ) and tumour necrosis factor- α (TNF- α ) (4 pg mL -1 ) along with substantial downregulation of ROS production in lipopolysaccharide (LPS)-inflamed cells. MBP-3 blocked the mRNA of NF- κ B, cyclooxygenase-2 (COX-2), and other cytokines, in lipopolysaccharide-induced macrophages. The potential to constrain inflammatory cytokine production revealed its application to develop functional food to attenuate inflammation-associated disorders.

The organic extract of Turbinaria conoides , a brown seaweed harvested from the Gulf of Manner region of Indian peninsular was chromatographically fractionated to yield three substituted 2 H- pyranoids, namely methyl-2 1 -yl-[5', 6'- dihydro-5'-yl-{5 4 -(4-hydroxybenzoyl)-oxy-(5 2 -methylbutyl)}-3'-methyl-2 H -pyran]-2 1 -methyl butanoate ( 1 ), 11-[(3', 6'-dihydro-4'-methyl-2'-oxo-2 H -pyran-3'-yl)methyl]-10-methylhexyl benzoate ( 2 ), and [6-ethyl-3,4-dimethyl-(tetrahydro-2', 2', 6'-trimethyl-2 H -pyran-3'-yl)-2,5-cycloheptadiene]-1-propanoate ( 3 ). The compounds 1 and 2 bearing 2 H -pyranyl-4-hydroxybenzoyl and 2 H -pyranyl-10-methylhexylbenzoate moieties exhibited potential antioxidant activities (IC 50 0.54-0.69 mg mL -1 ) as commercial antioxidant ( α -tocopherol IC 50 0.63-0.73 mg mL -1 ). Likewise, potential bioactivity of the 2 H -pyran derivative, 1 against 5-lipoxygenase (IC 50 ∼ 1 mg mL -1 ) along with higher index of selectivity (COX-1 inhibitory IC50 /COX-2 inhibitory IC50 1.88) indicated their selective anti-inflammatory properties against inducible inflammatory mediators than that displayed by commercially available non-steroidal anti-inflammatory drug (ibuprofen, 0.44). Structure activity relationship analysis of the studied compounds showed that the antioxidative and anti-inflammatory properties were directly proportional to their electronic properties. The previously undescribed 2H- pyranoids might constitute as potential antioxidative and anti-inflammatory pharmacophores for medicinal applications. [Formula: see text].