First report of antioxidant 1H-benzochromenone from muricid gastropod Chicoreus ramosus as dual inhibitors of pro-inflammatory 5-lipoxygenase and carbolytic enzymes.

Chromene derivatives with manifold structural framework and pharmacological properties were ubiquitous in the mollusks of marine origin. A previously undescribed 1H-benzochromenone was isolated through bioassay-guided chromatographic purification of the organic extract of the marine gastropod mollusk Chicoreus ramosus. The compound was characterised as 6-(2',2'-dimethyl)-3'-en-1'-yl-1'-oxy)-3-hydroxy-1H-benzo[c]chromene-2(10aH)-one based on integrated spectroscopic analysis. The antioxidant studies by employing the stable free radicals reported that the antioxidant activity (IC50 1.4-1.6 mM) was comparable to α-tocopherol (IC50 1.4-1.7 mM). The attenuating potential of the studied compound against pro-inflammatory 5-lipoxygenase (IC50 2.12 mM) was significantly greater than that exhibited by anti-inflammatory drug ibuprofen (IC50 4.4 mM), whereas its inhibitory properties against carbolytic α-amylase (IC50 ∼0.72 mM) was comparable with that displayed by acarbose (IC50 0.43 mM). The present study recognised the potential of 1H-benzochromenone derivative isolated from C. ramosus as important pharmaceutical lead with anti-diabetic and anti-inflammatory potentials to reduce the risk of hyperglycaemia and inflammatory pathologies.

Antioxidative 2H-chromenyls attenuate pro-inflammatory 5-lipoxygenase and carbolytic enzymes: Prospective bioactive agents from Babylonidae gastropod mollusk Babylonia spirata.

Oxygenated heterocycles are emerging as valuable pharmacophores involved in the prophylaxis and treatment of several diseases elicited by the reactive oxygen species. Bioassay-led chromatographic fractionation of the organic extract of the gastropod mollusk Babylonia spirata (family Babylonidae) yielded two unprecedented 2H-chromenyl derivatives characterized as 2-(butyryloxy)-5-hydroxy-hexahydro-2H-chromene-3-methyl carboxylate (1) and (3-hydroxy-hexahydro-2H-chromen-2-yl)methyl pentanoate (2). The chromenyl derivative (1) registered significantly greater attenuation potential against pro-inflammatory 5-lipoxygenase (IC50  ~ 2.02 mM) than those exhibited by the compound (2) (IC50 2.76 mM) and the non-steroidal anti-inflammatory drug ibuprofen (IC50 4.36 mM, p < .05). The compound (1) exhibited comparable antioxidant activity (IC50 1.47-1.72 mM) with standard antioxidative agent α-tocopherol (IC50 1.4-1.7 mM). Inhibitory potential of chromenyl derivative (1) toward α-glucosidase (IC50 1.18 mM) and α-amylase (IC50 0.92 mM) was greater than those displayed by 2 (IC50 1.16-1.56 mM). Structure-activity relationships revealed that bioactivities of the compounds were determined by the electronic factors and hydrophilic-lipophilic balance. PRACTICAL APPLICATIONS: The marine gastropod Babylonia spirata is one of the prominent edible gastropod species harvested from the coastlines along the southwestern region of the Indian peninsula. Two 2H-chromenyl derivatives were isolated to homogeneity from the organic extract of the marine buccinid gastropod B. spirata by the bioactivity-guided chromatographic fractionation and were found to possess potential antioxidant and attenuation properties against pro-inflammatory 5-lipoxygenase and carbolytic enzymes. The attenuation properties of the 2H-chromenyls against pro-inflammatory 5-lipoxygenase showed that 2H-chromenyl analogs possessed significantly greater anti-inflammatory potential than the non-steroidal anti-inflammatory drug ibuprofen. In particular, the chromenyl derivative bearing 2H-chromene-3-methyl carboxylate framework might constitute a prospective biogenic constituent in functional food and pharmaceutical applications for use against oxidative agents, including inflammation and hyperglycemic pathologies.

An unreported bis-abeo cembrane-type diterpenoid with antioxidative and anti-lipoxygenase activities from the muricid gastropod mollusc Chicoreus ramosus.

The chemical analyses of ethyl acetate-methanol (EtOAc-MeOH) extract of muricid gastropod mollusk, Chicoreus ramosus from the southeastern coast of Indian peninsular led to the identification of unprecedented cembrane-type diterpenoid, which was characterized as (3E, 6E, 10E)-8a-butoxy-17(15→14), 20(12→11)-bis-abeo-cembra-3,6,10,14(17),15-pentaene (1). The structure of the studied cembrane was unambiguously assigned through the extensive spectroscopic experimentations. The antioxidant potentials of the bis-abeo cembrane as determined by in vitro 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid diammonium salt radical quenching potentials were greater (IC50 < 0.40 mg/mL) related to α-tocopherol (IC50 > 0.60 mg/mL). The pro-inflammatory anti-5-lipoxygenase potential of studied cembrane was higher (IC50 < 0.80 mg/mL) related to those demonstrated by ibuprofen and sodium salicylate (IC50 > 0.90 mg/mL).

First report of a glycosaminoglycan-xylopyranan from the buccinid gastropod mollusk Babylonia spirata attenuating proinflammatory 5-lipoxygenase.

A previously undescribed xylated glycosaminoglycan characterized as ß-D-Xylop(1 â†’ 3)-(⋯ â†’ 4)-GlcpA(1 â†’ 3)-GlcpNAc(1 â†’ â‹¯) was purified from the buccinid gastropod Babylonia spirata and was evaluated for pharmacological properties using different in vitro models. The glycosaminoglycan-xylopyranan displayed prospective free radical quenching activities (IC50  < 0.7 mg/ml), whereas it exhibited potentially greater attenuation against the inductive proinflammatory enzyme 5-lipoxygenase (5-LOX, IC50 0.36 mg/ml) than the synthetic nonsteroidal anti-inflammatory drug aspirin (0.42). Gel permeation chromatography analysis specified the average molecular mass of the purified polysaccharide to be 231.88 kDa. The linkage sites, anomeric configuration, and the sequence of sugar residues of the purified xylated glycosaminoglycan were attributed by the inter-residue correlation obtained via two-dimensional nuclear resonance spectroscopic techniques. The results specified that the studied compound was composed of GlcpA(1 â†’ 3)-GlcpNAc (1 â†’ â‹¯) disaccharide repeating unit in the glycosaminoglycan backbone, with the xylose residues branching as C-3 substituents of the GlcpA. . PRACTICAL APPLICATIONS: The edible marine buccinid mollusk Babylonia spirata is a gastropod species of economic significance in the coastal regions of peninsular India. A previously unreported xylated glycosaminoglycan with a ß-D-Xylop(1 â†’ 3)-(⋯ â†’ 4)-GlcpA(1 â†’ 3)-GlcpNAc(1 â†’ â‹¯) framework was isolated to homogenity and was found to possess potential antioxidant and 5-lipoxygenase attenuation activities. The isolated metabolite might be anticipated as potential naturally-derived bioactive constituent in functional food and pharmaceutical applications.

Antioxidant drimane-type sesquiterpenoid from muricid gastropod Chicoreus ramosus attenuates pro-inflammatory 5-lipoxygenase and carbolytic enzymes.

The muricid gastropod, Chicoreus ramosus, is a nutrient-enriched food source available along the coastal peninsular of the Indian subcontinent. This study was aimed at bioactivity-directed chromatographic fractionation of the organic extract of C. ramosus to isolate an unprecedented drimane-type sesquiterpenoid Ramosane, characterized as 3-hydroxy-7,9b-dimethyl-5-methylene-8-pentyl-octahydro-1H-cyclopenta[a]naphthalen-9(2H)-one. The compound possessed potential antioxidant activities {2, 2'-diphenyl-1-picryl hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activities of IC50 1.42 mM and 1.72 mM, respectively} and was proportionate with those (IC50 1.39 and 1.69 mM, respectively) exhibited by α-tocopherol. The studied sesquiterpenoid exhibited potential attenuation property countering the pro-inflammatory 5-lipoxygenase (IC50  ~ 4 mM), and its activity was analogous with that exhibited by the anti-inflammatory ibuprofen (IC50 4.36 mM), whereas its carbolytic α-amylase activity (IC50 0.96 mM) was commensurate with that displayed by acarbose (IC50 0.43 mM). The isolated metabolite might anticipate as potential naturally derived bioactive constituent in functional food and pharmaceutical applications. PRACTICAL APPLICATIONS: The edible marine muricid gastropod C. ramosus is a prominently available gastropod species of commercial significance in the coastal regions of Indian Peninsula. An unprecedented drimane-type sesquiterpenoid Ramosane was isolated through the bioactivity-directed chromatographic fractionation of the organic extract of muricidae C. ramosus displaying potential anti-inflammatory and anti-diabetic properties. The present study apprehended the prospective of drimane-type sesquiterpenoid derivative Ramosane purified from C. ramosus as a naturally derived pharmacophore with anti-diabetic and anti-inflammatory potential for utilization in functional food and pharmaceutical formulations to minimize the likelihood of inflammation and hyperglycemic pathologies.

First report of a lactonic disecosteroid from the buccinid gastropod Babylonia spirata.

A lactonic steroid with an unprecedented 1, 10: 8, 9-disecoergostane framework was identified from the ethyl acetate-methanol extract of buccinid gastropod mollusk, Babylonia spirata collected from the southwestern coast of Indian peninsular region. The compound was characterized as 1, 10: 8, 9-disecoergosta-8-en-A-homo-6a-oxa-1-one by exhaustive spectroscopic methods including two-dimensional nuclear magnetic resonance and mass spectroscopic investigations. The disecosteroid displayed moderate carbolytic enzyme inhibition activity as distinguished by its inhibitive effects against α-amylase and α-glucosidase (IC50 0.40 and 0.54 mg/mL, respectively). The anti-inflammatory (5-lipoxidase inhibitory) activity of the titled secondary metabolite was found to be superior (IC50 < 0.85 mg/mL) than the commercial anti-inflammatory drug (ibuprofen IC50 > 0.85 mg/mL). However, significantly greater antioxidant property was recorded for the studied disecosteroid as evaluated by in vitro 2, 2-diphenyl-1-picrylhydrazyl radical inhibition potential (IC50 0.30 mg/mL) than that of standard, α-tocopherol (IC50 > 0.50 mg/mL). The in silico molecular docking studies were conducted to explain the anti-5-lipoxidase and anti-α-amylase properties of the isolated compound. The molecular binding interactions of the ligands with the pro-inflammatory 5-lipoxidase and the carbolytic enzyme α-amylase, demonstrated that their binding energies/docking scores were positively associated with their in vitro bioactivities. A plausible pathway for the biosynthetic origin of lactonic disecosteroid in B. spirata was proposed from an ergosterol precursor. Structure-activity correlation study demonstrated that the biological activities of the disecosteroid were directly proportional to their electronic properties allied with lesser steric restrictions.

First report of bioactive sterols from the muricid gastropod Chicoreus ramosus.

Two unusual △5 sterols with unprecedented skeletons were isolated from the organic extract of muricid gastropod Chicoreus ramosus collected off the Gulf of Mannar Coast. This is the first report of isolation of bioactive sterols endowed with anti-inflammatory potentials from this species. The compounds were characterized as (5Z)-24a-homo-cholesta-5,24a1(24a2) dien-3ß-ol (1) and 27(25 → 23)-abeo-(5Z)-3ß-hydroxy-24-isopropyl cholesteno-26,23-lactone (2) by the interpretation of a series of spectroscopic techniques involving two-dimensional nuclear magnetic resonance and mass spectral data. The compound 1 is unusual in that it has an ethylene attachment stemming from the additional methylene group at the 24a position of the steroid side chain, whereas compound 2 has a unique side chain bearing a γ-valerolactone ring. The △5 sterol bearing ethylene group (1) displayed comparatively better antidiabetic activity as characterized by inhibitory effects towards α-amylase and α-glucosidase enzymes (IC50 1.97 mM and 1.78 mM, respectively), whereas the cholestenolactone analogue (2) manifested higher anti-inflammatory activity (IC50 1.42 mM) as determined by in vitro 5-lipoxygenase inhibitory potential. Structure-activity correlation study showed that the biological activities of the studied sterols were directly related to their electronic properties. The homosterol (1) exhibiting improved antidiabetic properties showed higher lipophilic character coupled with lesser steric restrictions.