Antioxidant, antifungal, and aphicidal activity of the triterpenoids spinasterol and 22,23-dihydrospinasterol from leaves of Citrullus colocynthis L.

Terpenoids from natural plant sources are valuable for their diverse biological activities that have important roles in the medical and agrochemical industries. In this study, we assessed the antioxidant, antifungal, and aphicidal activities of a mixture of spinasterol and 22,23-dihydrospinasterol from the leaves of Citrullus colocynthis. We used 1,1-diphenyl-2-picrylhydrazyl (DPPH) to assess antioxidant activity, and we measured antifungal activity using mycelium growth inhibition assays with three pathogenic fungi, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora infestans. Aphicidal activity against adults of Myzus persicae was determined using in vitro and in vivo assays. Spinasterol and 22,23-dihydrospinasterol exhibited moderate antioxidant activity, even at lower concentrations: 19.98% at 0.78 µg mL-1, 31.52% at 3.0 µg mL-1, 36.61% at 12.5 µg mL-1, and 49.76% at 50 µg mL-1. Spinasterol and 22,23-dihydrospinasterol showed reasonable levels of fungicidal activity toward R. solani and M. grisea, with EC50 values of 129.5 and 206.1 µg mL-1, respectively. The positive controls boscalid and carbendazim were highly effective against all fungi except boscalid for M. grisea (EC50 = 868 µg mL-1) and carbendazim for P. infestans (EC50 = 8721 µg mL-1). Significant insecticidal activity was observed in both residual and greenhouse assays, with LC50 values of 42.46, 54.86, and 180.9 µg mL-1 and 32.71, 42.46, and 173.8 µg mL-1 at 72, 48, and 24 h, respectively. The antioxidant activity of spinasterol and 22,23-dihydrospinasterol was strongly positively correlated with their antifungal and insecticidal activity. Spinasterol and 22,23-dihydrospinasterol therefore show good antioxidant and aphicidal activity with moderate fungicidal activity, making them suitable candidates for an alternative to synthetic agents.

First report of seedling blight of maize caused by Fusarium asiaticum in Northeast China.

Maize [Zea mays L.] is an important food and feed crops in northeast of China. In 2019, maize seedling blight with an incidence of up to 25% was found at the field in Fushun city of Liaoning Province. Typical symptoms of seedlings were yellow, thin, wilt and die. The leaves gradually became yellow from the base of the plant to the top. Root system was poorly developed. The primary roots were usually discolored and rotted. And faintly pink or puce-coloured mould was found on seeds of the rotted seedings. Symptomatic roots of diseased seedling were collected and surface-disinfested with 70% ethanol for 1 min and then in 2% NaClO for 3 min, rinsed with sterilized water three times, cut into small pieces and placed on potato dextrose agar (PDA) medium for 5 days at 25 °C. Colonies on PDA were pink to dark red with fluffy aerial mycelium and red to aubergine pigmentation with the age. The causal agent was transferred to carnation leaf agar (CLA) medium and incubated at 25°C under a 12-h light-dark cycle. 12 Pure cultures were obtained from single conidia with an inoculation needle under stereomicroscope. The harvested macroconidia were hyaline, falcate with single foot cells, 3-5 septate and 28.2- 43.5 µm × 3.7 - 4.9 µm. Chlamydospores were globose to subglobose (5 to 13.5 µm). No microconidia were found. The perithecia were black, ostiolate subglobose. Asci were hyaline, clavate, measuring 58.1- 83.9 µm × 7.7- 11.9 µm and contained eight ascospores. Morphological characters of the pathogen agreed well with descriptions of Fusarium asiaticum (O'Donnell et al.2004; Leslie and Summerell 2006). To confirm the identity, partial translation elongation factor 1 alpha (TEF1-a) gene and rDNA internal transcribed spacer (ITS) region of isolate MSBL-4 were amplified and sequenced (O'Donnell et al. 2015; White et al.1990). BLASTn analysis of both TEF sequence (MT330257) and ITS sequence (MT322117), revealed 100% sequence identity with F. asiaticum KT380116 and KX527878, respectively. The isolate MSBL-4 was NIV chemotype as determined by Tri13F/DON, Tri13NIV/R (Chandler et al, 2003) assays. Pathogenicity studies were conducted on maize hybrid "Liaodan 565". Inoculum of F. asiaticum was prepared from the culture of MSBL-4 incubate in 2% mung beans juice on a shaker (150 rpm) at 25°C for 48 hours. The five liter pots (10 pots) were filled with sterilized field soil and five of them were mixed with conidial suspension (300mL in each pot) at 2 × 105 conidia per ml. Ten kernels per pot were surface disinfected in 2% sodium hypochlorite for 5 min, rinsed with sterilized water and planted. Five pots were inoculated and another uninoculated five pots served as controls. The pots were maintained in a greenhouse at 22-26°C for 40 days. Leaves of the plants in inoculated pots were yellowing and the roots became discolored or necrotic rot at 4 weeks after seedling emergence. All characteristics of the disease were similar to those observed in field. Non-inoculated control plants had no symptoms. Fusarium asiaticum was reisolated from inoculated plants and was identical to the original isolate. The experiment was repeated once with similar results. To our knowledge, this is the first report of seedling blight caused by F. asiaticum on maize in northeast China, and it has posed a threat to maize production of China. References: Leslie J F and Summerell BA. 2006. The Fusarium laboratory manual. Blackwell Publishing, Ames, pp 176-179. O'Donnell et al.2004. Fungal Genetics and Biology 41: 600-623. O' Donnell et al. 2015. Phytoparasitica 43:583-595. White T J et al. 1990. Academic Press, San Diego, CA, pp 315-322. Chandler E A et al. 2003. Physiological and Molecular Plant Pathology 62(6): 355-367.

Spinasterol, 22,23-Dihydrospinasterol and Fernenol from Citrullus Colocynthis L. with Aphicidal Activity against Cabbage Aphid Brevicoryne Brassicae L.

Brevicoryne brassicae is a problematic pest in cabbage and other field crops. Synthetic pesticides are used to control this pest, but they are injurious for human health and the environment. The present study aimed to purify and identify the active compounds from Citrullus colocynthis leaves with an appraisal of their efficacy against B. brassicae. Separation and purification were performed via different chromatographic techniques. Molecular analysis and chemical structures were recognized by mass spectrum (MS) and nuclear magnetic resonance (NMR), respectively. Moreover, in vitro and in vivo aphicidal activity was assessed using various concentrations, i.e., 6.25, 12.5, 25 and 50 µg/mL at 12, 24, 48 and 72 h exposure. The outcome shows that mass spectrum analyses of the purified compounds suggested the molecular formulae are C30H50O and C29H50O, C29H48O. The compounds were characterized as fernenol and a mixture of spinasterol, 22,23-dihydrospinasterol by 1H-NMR and 13C-NMR spectrum analysis. The toxicity results showed that the mixture of spinasterol and 22,23-dihydrospinasterol showed LC50 values of 32.36, 44.49 and 37.50 µg/mL by contact, residual and greenhouse assay at 72 h exposure, respectively. In contrast, fernenol recorded LC50 values as 47.99, 57.46 and 58.67 µg/mL, respectively. On the other hand, spinasterol, 22,23-dihydrospinasterol showed the highest mortality, i.e., 66.67%, 53.33% and 60% while, 30%, 23.33% and 25% mortality was recorded by fernenol after 72 h at 50 µg/mL by contact, residual and greenhouse assay, respectively. This study suggests that spinasterol, 22,23-dihydrospinasterol are more effective against B. brassicae which may be introduced as an effective and suitable substitute of synthetic chemical pesticides.

Novel sulfonamides against Botrytis cinerea with no positive cross-resistance to commercial fungicides: Design, synthesis and SAR study.

Thirty-four novel compounds were synthesized using chesulfamide (N-(2-trifluoromethyl-4-chlorophenyl)-2-oxocyclohexyl sulfonamide), a high-profile fungicide, as the lead compound, and their structures were characterized by 1H NMR, 13C NMR, MS and elemental analysis. Additionally, the structure of (1S,2R)-2-((3-bromophenethyl)amino)-N-(4-chloro-2-trifluoromethylphenyl)cyclohexane-1-sulfonamide (IV-9) was confirmed by X-ray single crystal diffraction. The mycelium inhibition tests, spore germination inhibition tests, tomato pot tests and field trials were performed against strains of B. cinerea. Bioassay results showed that most of target compounds had good fungicidal activity against B. cinerea, in particular, IV-9 exhibited similar or superior effects to procymidone, boscalid and pyrisoxazole in all in vitro and in vivo tests. Moreover, there was no positive cross-resistance found between the compound IV-9 and eight commercial fungicides (azoxystrobin, boscalid, chlorothalonil, diethofencarb, fludioxonil, procymidone, pyrimethanil and pyrisoxazole) in the cross-resistance validation test performed by an innovative method.

Phytochemical Analysis, Biochemical and Mineral Composition and GC-MS Profiling of Methanolic Extract of Chinese Arrowhead Sagittaria trifolia L. from Northeast China.

Sagittaria trifolia is a medicinal foodstuff of China and East Asia belonging to the family Alismataceae. Samples of S. trifolia tubers were collected from Meihekow, Siping, Jilin, Harbin and Wuchang from Northeast China. The current study was aimed to evaluate the qualitative and quantitative analysis, antioxidant activity, biochemical analysis and chemical composition of different populations of S. trifolia. By using Folin-Ciocalteu, aluminium chloride colourimetric and 1,1-diphenyl-1-picrylhydrazyl (DPPH), total phenol and flavonoids content and antioxidant activity was analysed. Furthermore, chemical composition, biochemical analysis and mineral substances were also determined. The results showed the presence of flavonoids, phenols, saponins, tannins, glycosides and steroids except for alkaloids and terpenoids by qualitative analysis. Quantitative analysis revealed that highest total phenol, flavonoids content and antioxidant potential identified from Meihekow, i.e., 2.307 mg GAE/g, 12.263 mg QE/g and 77.373%, respectively. Gas chromatography-mass spectrometry results showed the presence of 40 chemical compounds corresponding to 99.44% of total extract that might be responsible for antioxidant properties. Mineral and biochemical analysis revealed the presence of calcium, magnesium, potassium, sodium, iron, copper, zinc and, carbohydrate, protein, fibre and fat contents, respectively. Interestingly, all S. trifolia populations collected from different locations possess similar composition. The dietary values, phytoconstituents, antioxidant activities and nutritional and curative chemical compounds of S. trifolia are beneficial for the nutritherapy of human beings.

Synthesis, Fungicidal Activity and SAR of 2-Thiazolamide/Pyrazolamide-Cyclohexylsulfonamides against Botrytis cinerea.

In order to explore more efficient sulfonamides against Botrytis cinereal, 36 novel cyclohexylsulfonamides were synthesized by N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDCI) and 1-hydroxybenzotriazole (HOBt) condensation reaction using chesulfamide as a lead compound, introducing thiazole and pyrazole active groups. Their structures were characterized by 1H-NMR, 13C-NMR, mass spectrum (MS), and elemental analysis. Compound III -31 was further confirmed by X-ray single crystal diffraction. The in vitro and in vivo fungicidal activities against B. cinerea were evaluated by three bioassay methods. The results of mycelial growth demonstrated that median effective concentration (EC50) values of nine compounds were close to boscalid (EC50 = 1.72 µg/mL) and procymidone (EC50 = 1.79 µg/mL) against B. cinerea (KZ-9). In the spore germination experiment, it was found that compounds III-19 and III-31 inhibited germination 93.89 and 98.00%, respectively; at 10 µg/mL, they approached boscalid (95.97%). In the tomato pot experiment, the control effects of two compounds (III-21 and III-27) were 89.80 and 87.90%, respectively, at 200 µg/mL which were significantly higher than boscalid (81.99%). The structure-activity relationship (SAR) was also discussed, which provided a valuable idea for developing new fungicides.

Development of novel 2-substituted acylaminoethylsulfonamide derivatives as fungicides against Botrytis cinerea.

Botrytis cinerea is an economically important fungal pathogen with a host range of over 200 plant species. Unfortunately, gray mold disease caused by B. cinerea has not been effectively controlled because of its high risk for fungicide resistance development. As a part of our ongoing efforts to develop novel sulfonamides as agricultural fungicides against Botrytis cinerea, we introduced 2-aminoethanesulfonic acid (taurine) substructure, designed and synthesized a series of novel 2-substituted acylaminoethylsulfonamides. The newly synthesized sulfonamides were evaluated in vitro and in vivo for their fungicidal activity against Botrytis cinerea, of which the 2-ethoxyacetylamide derivative (V-A-12, EC50 = 0.66 mg·L-1) exhibited the highest potency in vitro and superior fungicidal activity compared with procymidone (EC50 = 1.06 mg·L-1). In vivo bioassay indicated that compound V-A-12 could be effective for the control of tomato gray mold. Moreover, the structure-activity relationship of these sulfonamides was analyzed by establishing a three-dimensional quantitative structure-activity relationship (3D-QSAR) model, which can provide guidance for the development of sulfonamides as fungicides. Finally, the effeicacy of sulfonamide derivatives was again verified in the activity evaluation against resistant Botrytis cinerea strains. These results further enhance the development value of 2-substituted acylaminoethylsulfonamides to control the tomato gray mold.

Design, Synthesis, and SAR of Novel 2-Glycinamide Cyclohexyl Sulfonamide Derivatives against Botrytis cinerea.

N-(2-trifluoromethyl-4-chlorophenyl)-2-oxocyclohexyl sulfonamide (chesulfamide) is in the limelight as a novel fungicide, and has fungicidal activity against Botrytis cinerea. For exploring more novel structures, 33 new compounds were synthesized by N-alkylation and acid-amine coupling reactions with chesulfamide as the core moiety, and their structures were characterized and established by ¹H-NMR, 13C-NMR, MS, and elemental analysis. The structure of (1R,2S)-2-(2-(N-(4-chloro-2-trifluoromethylphenyl)sulfamoyl)-cyclohexylamino)-N-(2-trifluoromethylphenyl) acetamide (II-19) was defined by X-ray single crystal diffraction. The in vivo and in vitro fungicidal activities against B. cinerea were evaluated. The bioassay results of mycelial growth demonstrated that most compounds exhibited excellent inhibitory activity against B. cinerea at 50 µg mL-1, and 7 compounds showed lower EC50 values than boscalid (EC50 = 4.46 µg mL-1) against B. cinerea (CY-09). In cucumber pot experiment, the inhibitory rates of four compounds (II-4, II-5, II-12, and II-13) against B. cinerea were 90.48, 93.45, 92.86, and 91.07, which were better than cyprodinil (88.69%), the best performing of all controls. In tomato pot experiment, the control efficacy of two analogs (II-8 and II-15) were 87.98 and 87.97% at 200 µg mL-1, which were significantly higher than boscalid (78.10%). Most compounds have an excellent fungicidal effect on B. cinerea, with potential as a lead compound for developing new pesticides.

Design, Synthesis and Fungicidal Activity of 2-Substituted Phenyl-2-oxo-, 2-Hydroxy- and 2-Acyloxyethylsulfonamides.

Sulfonyl-containing compounds, which exhibit a broad spectrum of biological activities, comprise a substantial proportion of and play a vital role, not only in medicines but also in agrochemicals. As a result increasing attention has been paid to the research and development of sulfonyl derivatives. A series of thirty-eight 2-substituted phenyl-2-oxo- III, 2-hydroxy- IV and 2-acyloxyethylsulfonamides V were obtained and their structures confirmed by IR, ¹H-NMR, and elemental analysis. The in vitro and in vivo bioactivities against two Botrytis cinerea strains, DL-11 and HLD-15, which differ in their sensitivity to procymidone, were evaluated. The in vitro activity results showed that the EC50 values of compounds V-1 and V-9 were 0.10, 0.01 mg L-1 against the sensitive strain DL-11 and 3.32, 7.72 mg L-1 against the resistant strain HLD-15, respectively. For in vivo activity against B. cinerea, compound V-13 and V-14 showed better control effect than the commercial fungicides procymidone and pyrimethanil. The further in vitro bioassay showed that compounds III, IV and V had broad fungicidal spectra against different phytopathogenic fungi. Most of the title compounds showed high fungicidal activities, which could be used as lead compounds for further developing novel fungicidal compounds against Botrytis cinerea.

Synthesis, Fungicidal Activity, and Structure Activity Relationship of ß-Acylaminocycloalkylsulfonamides against Botrytis cinerea.

In order to discover new antifungal agrochemicals that could have highly active and novel motifs, thirty-six new 2-acylaminocycloalkylsulfonamides (IV) were synthesized. Their structures were characterized and confirmed by 1H NMR, 13C NMR, IR, MS, elemental analysis and X-ray single crystal diffraction. In vitro and in vivo activities against various Botrytis cinerea strains were evaluated. Bioassay results revealed that most of the title compounds exhibited excellent in vitro fungicidal activity, in which compound IV-26 showed the highest activity against sensitive, low-resistant, moderate-resistant and high-resistant strains of B. cinerea compared with the positive fungicide procymidone. Meanwhile in vivo fungicidal activity of compound IV-31 was better than the commercial fungicides procymidone and chesulfamide in greenhouse trial. The structure activity relationship (SAR) was also discussed and the results were of importance to the structural optimization and development of more potent sulfonamides antifungal agents.

Design, synthesis and fungicidal activity of novel 2-substituted aminocycloalkylsulfonamides.

A series of novel 2-substituted aminocycloalkylsulfonamides were designed and synthesized by highly selective N-alkylation reaction, whose structures were characterized by 1H NMR, 13C NMR and HRMS. Among them, the configuration of compounds III12 and III20 were confirmed by X-ray single crystal diffraction. Bioassays demonstrated that the title compounds had considerable effects on different strains of Botrytis cinerea and Pyricularia grisea. Comparing with positive control procymidone (EC50=10.31mg/L), compounds III28, III29, III30 and III31 showed excellent fungicidal activity against a strain of B. cinerea (CY-09), with EC50 values of 3.17, 3.04, 2.54 and 1.99mg/L respectively. Their in vivo fungicidal activities were also better than the positive controls cyprodinil, procymidone, boscalid and carbendazim in pot experiments. Moreover, the fungicidal activity of III28 (EC50=4.62mg/L) against P. grisea was also better than that of the positive control isoprothiolane (EC50=6.11mg/L). Compound III28 would be great promise as a hit compound for further study based on the structure-activity relationship.

Toxicity of amorphigenin from the seeds of Amorpha fruticosa against the larvae of Culex pipiens pallens (Diptera: Culicidae).

The larvicidal activity of the crude petroleum ether, ethyl acetate, acetone, chloroform and ethanol extracts of Amorpha fruticosa seeds was individually assayed for toxicity against the early fourth-instar larva of the mosquito, Culex pipiens pallens after 24 h exposure. Of the tested extracts, the ethanol one exhibited the highest larvicidal activity (LC50 = 22.69 mg/L). Amorphigenin (8'-hydroxyrotenone), a rotenoid compound which exhibits a strong larvicidal activity with LC50 and LC90 values of 4.29 and 11.27 mg/L, respectively, was isolated from the ethanol extract by column chromatograpy. Its structure was elucidated by 1H-NMR, UV and IR spectral data. Furthermore, investigation of amorphigenin's effects on mitochondrial complex I activity and protein synthesis in C. pipiens pallens larvae reveals that amorphigenin decreases mitochondrial complex I activities to 65.73% at 10.45 µmol/L, compared to the control, when NADH were used as the substrate. Meanwhile, amorphigenin at 10.45 µmol/L also caused a 1.98-fold decrease in protein content, compared to the control larvae treated with acetone only.

Synthesis of rotenone-O-monosaccharide derivatives and their phloem mobility.

Six monosaccharide derivatives of rotenone were designed and synthesized to assess whether rotenone could become phloem mobile by the addition of a monosaccharide group. Phloem mobility experiments showed that only D-glucose conjugates exhibit phloem transport properties in castor bean (Ricinus communis L.) seedlings. Two D-glucose conjugates, 2-O-ß-D-glucopyranosyldemethylrotenone and 6'-O-ß-D-glucopyranosyldalpanol, had significantly obtained systemicity compared with that of rotenone, and 6'-O-ß-D-glucopyranosyldalpanol was more mobile than 2-O-ß-D-glucopyranosyldemethylrotenone. Coupling with a monosaccharide core is a reasonable method for conferring phloem mobility on insecticides, but phloem mobility is also affected by the parent molecule and the position of the monosaccharide.

Poly[(µ(4)-tetra-zole-1-acetato-κN:N:O:O')silver(I)].

In the title complex, [Ag(C(3)H(3)N(4)O(2))](n), the Ag(I) atom is four-coordinated in a slightly distorted tetra-hedral coordination geometry by two N atoms from two tetra-zole-1-acetate (tza) ligands and two O atoms from the other two tza ligands. The tza ligand bridges two Ag atoms through the carboxyl-ate O atoms and simultaneously binds to the other two Ag atoms through the tetra-zole N atoms, forming a two-dimensional network parallel to (100).

Hexaaqua-nickel(II) 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate monohydrate.

In the title compound, [Ni(H(2)O)(6)](C(16)H(12)O(6))·H(2)O, the Ni(II) cation is located on a mirror plane and is coordinated by six water mol-ecules, two of which are also located on the mirror plane, in a distorted octa-hedral geometry. The 4,4'-(1,2-dihy-droxy-ethane-1,2-di-yl)dibenzoate anion is centrosymmetric with the mid-point of the central ethane C-C bond located on an inversion center. The uncoordinated water mol-ecule is located on a mirror plane. Extensive O-H⋯O hydrogen bonding is present in the crystal structure.

Diaqua-bis-(4-carb-oxy-2-propyl-1H-imidazole-5-carboxyl-ato-κN,O)cobalt(II) N,N-dimethyl-formamide disolvate.

In the title complex, [Co(C(8)H(9)N(2)O(4))(2)(H(2)O)(2)]·2C(3)H(7)NO, the Co(II) cation (site symmetry ) is six-coordinated by two 5-carb-oxy-2-propyl-1H-imidazole-4-carboxyl-ate ligands and two water mol-ecules in a distorted octa-hedral environment. In the crystal structure, the complex mol-ecules and dimethyl-formamide solvent mol-ecules are linked by extensive O-H⋯O and N-H⋯O hydrogen bonding into sheets lying parallel to (21).

Tetra-aquabis(6-carboxy-1H-benzimid-azole-5-carboxyl-ato-κN)nickel(II) dimethyl-formamide disolvate dihydrate.

The title compound, [Ni(C(9)H(45)N(2)O(4))(2)(H(2)O)(4)]·2C(3)H(7)NO·2H(2)O, has the Ni(II) center coordinated by four water mol-ecules and two N atoms from two 1H-benzimidazole-5,6-dicarboxyl-ate ligands in an octa-hedral geometry. The mol-ecule inter-acts with the solvent water and dimethyl-formamide mol-ecules through N-H⋯O and O-H⋯O hydrogen bonds to form a three-dimensional supra-molecular network. The metal atom lies on a center of inversion.

Penta-aqua-(1H-benzimidazole-5,6-dicarboxyl-ato-κN)nickel(II) penta-hydrate.

In the title mononuclear complex, [Ni(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, the Ni(II) atom is six-coordinated by one N atom from a 1H-benzimidazole-5,6-dicarboxyl-ate ligand and by five O atoms from five water mol-ecules and displays a distorted octa-hedral geometry. Inter-molecular O-H⋯O hydrogen-bonding inter-actions among the coordinated water mol-ecules, solvent water mol-ecules and carboxyl O atoms of the organic ligand and additional N-H⋯O hydrogen bonding lead to the formation of a three-dimensional supra-molecular network.

catena-Poly[[diaqua-(1,10-phenanthroline-κN,N')nickel(II)]-µ-1H-benzimidazole-5,6-dicarboxyl-ato-κN:O].

In the title complex, [Ni(C(9)H(4)N(2)O(4))(C(12)H(8)N(2))(H(2)O)(2)](n), the Ni(II) atom is hexa-coordinated by one N and one O atom from two different 1H-benzimidazole-5,6-dicarboxyl-ate ligands, two N atoms from one 1,10-phenanthroline ligand and two water mol-ecules. The flexible 1H-benzimidazole-5,6-dicarboxyl-ate ligands link the Ni(II) centres, forming an infinite zigzag chain parallel to [001]. The crystal packing is governed by inter-molecular hydrogen-bonding inter-actions of the O-H⋯O, N-H⋯O and C-H⋯O types.

Penta-aqua-(1H-benzimidazole-5,6-di-carboxyl-ato-κN)cobalt(II) penta-hydrate.

In the title mononuclear complex, [Co(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, the Co(II) atom exhibits a distorted octa-hedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxyl-ate ligand and five water O atoms. A supra-molecular network is generated through inter-molecular O-H⋯O hydrogen-bonding inter-actions involving the coordinated and uncoordinated water mol-ecules and the carboxyl O atoms of the organic ligand. An inter-molecular N-H⋯O hydrogen bond is also observed.