Identification of the Chemotypes of Ocimum forskolei and Ocimum basilicum by NMR Spectroscopy

The chemotypes of Ocimum forskolei Benth and Ocimum basilicum L. growing wild in Oman have been established by ¹³C‐NMR analyses of the vegetative and floral oils of the plants. The chemotypes, estragole for O. forskolei and linalool for O. basilicum, suggested by ¹³C‐NMR fingerprinting were also confirmed by GC‐FID and GC/MS analyses. The oil of O. forskolei demonstrated better activities against bacteria and dermatophytes. The significance of the presence of estragole and linalool in the volatile oils of plants whose fragrances are traditionally inhaled, added to food, or rubbed on the skin are discussed.     

Enhancing antidiabetic and antimicrobial performance of Ocimum basilicum,and Ocimum sanctum (L.) using silver nanoparticles

The role of silver nanoparticles (AgNps) is an attractive proposition for advancing modern diabetes therapies and applied science. Stable AgNps with a size range of 3–25 nm were synthesized using aqueous leaf extracts from Ocimum basilicum, Ocimum sanctum, and in combination. The concentration of the extracts facilitated the reduction of silver nitrate that led to the rapid formation of AgNps at room temperature, indicating a higher reaction rate as opposed to harsh chemical methods, and high conversion energy usually involved in the synthesis. The size, shape and elemental analysis were carried out using UV–Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX), dynamic light scattering (DLS), and zeta potential whilst, Fourier transform infrared (FTIR) supported by gas chromatography mass spectroscopy (GC–MS) was used to identify the type of capping agents. Inhibition of α-amylase and α-glucosidase enzymes retards the rate of carbohydrate digestion, thereby provides an alternative and a less evasive strategy of reducing postprandial hyperglycaemia in diabetic patients. The AgNps derived from O. sanctum and O. basilicum, respectively displayed an inhibitory effect at 89.31 ± 5.32%, and 79.74 ± 9.51%, respectively, against Bacillus stearothermophilus α-glucosidase enzyme model, indicating an enhanced biocatalytic potential compared to their respective crude extracts and the control. Furthermore, the emerging rate of infections in diabetic patients validates the need for the discovery of dual diabetes therapies. As a result, the bioderived AgNps displayed antimicrobial activity against bacterial species Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Salmonella species.     

Inhibitory effects of essential oils from Ocimum basilicum and Ocimum gratissimum on Colletotrichum musae: The causal agent of bananas anthracnose

This study aimed to investigate the fungicidal effects of essential oils (EO) from Ocimum sp. on Colletotrichum musae. The fungus was isolated from bananas that showed typical symptoms of anthracnose followed by molecular identification. Oils were obtained by hydro‐distillation, and the chemical constituents were analysed using gas chromatography. The antifungal activity of the oils was tested in vitro against mycelia growth and conidia germination. In situ tests were carried out by spraying the oil on healthy bananas followed by the inoculation with C. musae conidia and the assessment of the necrosis symptoms. The obtained results revealed that the yield of the oil extracted from Ocimum basilicum and Ocimum gratissimum were 0.17% and 0.40%, respectively. Thujanol (24.38%), eugenol (23.78%) and (Z)‐ß‐ocimene (16.59%) were the main components found in O. basilicum while thymol (42.65%), trans‐sabinene hydrate (21.63%) and limonene (8.68%) were the major components found in O. gratissimum. The total reduction in the C. musae mycelial growth was observed at 800 and 275 µl/L, for the O. basilicum and O. gratissimum oils, respectively. These oils also inhibited completely the conidia germination at 400 and 185 µl/L. In situ tests showed the necrosis reduction bananas anthracnose. The minimum inhibitory concentration (MIC) for the preventive and curative test after the application of O. basilicum oil was 6,000 and 4,000 µl/L, respectively, whereas for the O. gratissimum oil, the MIC was 3,000 and 1,000 µl/L, jointly. Positive correlations were identified between the oil concentration and the reduction in bananas necrosis. These results indicated that the O. gratissimum EOs might be used as a biocide for the control of bananas anthracnose disease.     

Antioxidant and radioprotective properties of an Ocimum sanctum polysaccharide

The antioxidant activity of two polysaccharides isolated from the Indian medicinal plants, Ocimum sanctum and Tinospora malabarica, was studied. Only the O. sanctum polysaccharide (OSP) showed significant activity. OSP could prevent oxidative damage to liposomal lipids and plasmid DNA induced by various oxidants such as iron, AAPH and gamma-radiation, besides scavenging important ROS such as the superoxide radical and hydrogen peroxide and inhibiting xanthine oxidase. In addition, OSP could prevent gamma-radiation-mediated cell deaths in mouse splenocytes.     

罗勒的组织培养和快速繁殖

1植物名称罗勒(Ocimum basilicum L.). 2材料类别顶芽或带腋芽茎段. 3培养条件基本培养基为MS培养基.(1)诱导愈伤组织培养基:MS 6-BA 4 mg·L-1(单位下同) NAA 0.1;(2)诱导丛生芽及生根培养基:MS 6-BA 3 NAA 0.5.以上培养基均含1%琼指、3%蔗糖,pH 5.6～5.8.高压灭菌锅中121℃下灭菌20 min.培养温度为23～24℃,光照时间12 h·d-1,光照度为1 000～1 500 lx.     

Molecular and chemical characterization of the most widespread Ocimum species

DNA fingerprinting (AFLP) and chemical analyses of essential oils were utilized to define the extent of variation existing in the genus Ocimum. Research was carried out on 22 Ocimum accessions representing seven species. Concerning the essential oil composition of all investigated accessions, 115 compounds were identified. UPGMA cluster analysis, based on Euclidian distances of essential oil constituents between all pairs of accessions, showed four well-supported clusters (O. tenuiflorum, O. basilicum/O. africanum, O. basilicum, and O. americanum/O. africanum). Relating to the essential oil composition of all of the investigated accessions, 17 compounds were identified as the main ones, and according to them 13 chemotypes were determined. AFLP relationships were determined by neighbor-joining (NJ) cluster analysis based on Dice??s distance matrix and by maximum parsimony (MP) analysis. O. basilicum, O. americanum/O. africanum, O. tenuiflorum, and O. gratissimum represented four clusters supported with high bootstrap values. A neighbor-net diagram allowed the visualization of apparently conflicting data by revealing relationships between genotypes and chemotypes. Concerning the O. africanum species, two distinct chemotypes, geranial/neral (accession 11) and estragol (accession 10), have been established, while all the studied O. americanum accessions belong to the geranial/neral chemotype. This could be additional evidence that O. americanum is one of the parents of O. africanum. Furthermore, the fact that the O. africanum accession (10) as well as O. basilicum ??Purpurascens?? and O. basilicum ??Erevanskii?? accessions belong to the estragol chemotype supports the theory that O. africanum is one of the parents of these two O. basilicum accessions.     

Endophytic Bacteria from Ocimum sanctum and Their Yield Enhancing Capabilities

Endophytes are beneficial microbes that reside intercellularly inside the plants. Interaction of endophytes with the host plants and their function within their host are important to address ecological relevance of endophyte. Four endophytic bacteria OS-9, OS-10, OS-11, and OS-12 were isolated from healthy leaves of Ocimum sanctum. These isolated microbes were screened in dual culture against various phytopathogenic fungi viz. Rhizoctonia solani, Sclerotium rolfsii, Fusarium solani, Alternaria solani, and Colletotrichum lindemuthianum. Of these, strain OS-9 was found to be antagonistic to R. solani, A. solani, F. solani, and C. lindemuthianum while OS-11 was found antagonistic against A. solani only. The growth-promoting benefits of the endophytes were initially evaluated in the glasshouse by inoculated seeds of O. sanctum. Treatment with endophytes OS-10 and OS-11 resulted in significant enhancement of growth as revealed by increase in fresh as well as dry weight. Further, field trials involving two genotypes OS Purple and CIM-Angana were conducted with strains OS-10 and OS-11. The growth-promoting effect was visible on both the genotypes tested as the endophytes significantly enhanced fresh herbage yield (t/ha). Interestingly, these endophytes increased the content of essential oil particularly in cultivar OS Purple and thereby increasing the total oil yields. Molecular characterization of strain OS-11 indicated the strain to be highly related to the type strain of Bacillus subtilis.     

Fungitoxic and Phytotoxic Studies with Essential Oil of Ocimum adscendens

On screening the leaf extracts of some higher plants for their volatile antifungal activity against the test organism Aspergillus flavus, the extract of Ocimum adscendens exhibited the strongest fungitoxicity. The leaves showed maximum, fungitoxicity as compared with other plant parts. The volatile fungitoxic fraction obtained as an essential oil was standardized by various physico-chemical properties. The oil showed its fungicidal nature and broad range of activity at its minimum inhibitory concentration. The oil was thermostable and the toxicity remained unchanged even on autoclaving and on storage for up to 360 days. Moreover, the oil proved more active than some prevalent synthetic fungicides and exhibited no phytotoxic effect onVigna radiata.     

Leaf flavonoid glycosides as chemosystematic characters in Ocimum

Thirty-one accessions of nine species belonging to three subgenera of Ocimum (basil, family Lamiaceae) were surveyed for flavonoid glycosides. Substantial infraspecific differences in flavonoid profiles of the leaves were found only in O. americanum, where var. pilosum accumulated the flavone C-glycoside, vicenin-2, which only occurred in trace amounts in var. americanum and was not detected in cv. Sacred. The major flavonoids in var. americanum and cv. Sacred, and also in all other species investigated for subgenus Ocimum, were flavonol 3-O-glucosides and 3-O-rutinosides. Many species in subgenus Ocimum also produced the more unusual compound, quercetin 3-O-(6″-O-malonyl)glucoside, and small amounts of flavone O-glycosides. The level of flavonol glycosides produced was reduced significantly in glasshouse-grown plants, but levels of flavone glycosides were unaffected. A single species investigated from subgenus Nautochilus, O. lamiifolium, had a different flavonoid glycoside profile, although the major compound was also a flavonol O-glycoside. This was identified as quercetin 3-O-xylosyl(1‴→2″)galactoside, using NMR spectroscopy. The species investigated from subgenus Gymnocimum, O. tenuiflorum (=O. sanctum), was characterised by the accumulation of flavone O-glycosides. These were isolated, and identified as the 7-O-glucuronides of luteolin and apigenin. Luteolin 5-O-glucoside was found in all nine species of Ocimum studied, and is considered to be a key character for the genus.     

Chemical characterization and genetic relationships among Ocimum basilicum L. cultivars

Twenty-seven Ocimum basilicum cultivars were subjected to a chemical characterization of essential oil components by gas chromatography/mass spectrometry (GC/MS) and a genetic characterization using the amplified fragment-length polymorphism (AFLP) technique. Since the same 27 accessions had previously been classified into six morphotypes, these analyses allowed us to make detailed comparisons of chemistry, genetics, and morphology. The chemical composition and morphology of the studied cultivars appeared to have a strong genetic component. The AFLP analysis revealed a distinction between the green and purple morphotypes. The green morphotypes predominantly utilized the terpene biosynthetic pathway, while most purple morphotypes primarily utilized the phenylpropene biosynthetic pathway. The GC/MS analysis led to identification of 87 volatiles. Among the 27 cultivars, five chemotypes were identified. A detailed characterization of the essential oil constituents indicated the existence of both specific combinations of compounds and 'private' compounds with the potential to be used in many aspects of human life. The established relationship between a genetic profile, chemical composition, and morphology represents an important step in future breeding programs and in the cultivation of this species.     

Chemical profiling of Ocimum americanum using external flavonoids

A HPLC survey was undertaken of the external flavonoids in 111 herbarium specimens of Ocimum americanum L. (O. canum Sims), which were largely collected from their natural habitats throughout Africa and Asia. The purpose of this study was to establish the flavonoid profiles of this species over the full range of its geographic distribution in order to use these for authentication purposes. Six different external flavonoid chemotypes were found. The major chemotype, present in circa 80% of the specimens of both var. americanum and var. pilosum collected throughout the distribution area of the species, was characterised by very high levels of nevadensin, slightly lower levels of salvigenin and much lower levels of up to 15 other external flavones. Of the remaining five chemotypes, two were found in var. americanum and three in var. pilosum. All specimens belonging to these chemotypes were collected in South or East Africa and represented by only a few specimens. These samples contained much smaller levels of flavones than present in the major chemotype of O. americanum and all lacked nevadensin. Xanthomicrol, a compound absent from the main chemotype, was the dominant flavone in two of the minor chemotypes. The external flavonoid profiles found in the six chemotypes of O. americanum were compared with those of O. x citriodorum (11 herbarium specimens studied) and seven other closely related species of Ocimum. The main nevadensin/salvigenin pattern present in O. americanum was also found in O. x citriodorum, O. basilicum and some specimens of O. minimum, but there were strong quantitative differences in external flavonoids among these taxa. The other chemotypes of O. americanum showed some similarities in their external flavone profiles to those found in the closely related East African species O. fischeri, O. forskolei, O. kenyense and O. kilimandscharicum, which occur in the same geographic areas. This suggests that the uncommon chemotypes of O. americanum may have originated by an exchange of genes with other Ocimum species, e.g. by introgressive hybridisation. Despite some similarities in profiles, chemical differences were also found among the species, so that it should be possible to authenticate a large proportion of leaf samples of O. americanum on the basis of external flavonoid profiles.     

薄荷和罗勒提取物体外抗氧化及保肝活性研究

采用国际常用的ABTS和DPPH方法评价唇形科植物薄荷(Mentha haplocalyx) 和罗勒(Ocimum basilicum)水提物和乙醇提取物体外抗氧化活性,选用HepG2细胞,通过乙醇诱导损伤,构建体外酒精性肝损伤细胞模型,以细胞存活率评价薄荷和罗勒提取物的保肝效果。结果表明,DPPH自由基清除能力大小依次为薄荷醇提物、薄荷水提物、罗勒醇提物、罗勒水提物,半效应浓度(EC₅₀)分别为70.42 μg·mL^-1、75.77 μg·mL^-1、354.87 μg·mL^-1、451.53 μg·mL^-1。ABTS自由基清除能力大小依次为薄荷醇提物、罗勒醇提物、薄荷水提物、罗勒水提物,EC50值分别为9.04 μg·mL^-1、18.03 μg·mL^-1、22.18 μg·mL^-1、36.88 μg·mL^-1。薄荷提取物的抗氧化能力整体优于罗勒提取物,醇提物抗氧化能力优于水提物。酒精性肝损伤细胞活性检测表明,5、10、20、50 μg·mL^-1薄荷水提物、薄荷醇提物和罗勒水提物能剂量依赖性地提高乙醇诱导损伤的细胞存活率,具有一定的保肝活性。     

Blend effects in the toxicity of the essential oil constituents of Ocimum kilimandscharicum and Ocimum kenyense (Labiateae) on two post-harvest insect pests

The lethal toxicity of major components of the essential oils of Ocimium kilimandscharicum and O. kenyense and of selected blends of these against Sitophilus zeamais and Rhyzopertha dominica were compared with those of the full blends of the essential oils. The compounds were assayed in amounts and proportions present in the minimum 100% lethal dose of the oils. Whereas a major component of O. kilimandscharicum was found to be largely responsible for the toxic action of its essential oil against R. dominica, the results with the other treatments indicated that the toxic action of the essential oils were due to the combined effects of different components, either with or without significant individual toxic action of their own against the insects. The significance of the results and their implication in screening and using plants and their phytochemicals for pest and microbial control are highlighted.     

Antibacterial activity of Ocimum sanctum L. fixed oil

Ocimum sanctum fixed oil showed good antibacterial activity against Staphylococcus aureus, Bacillus pumilus and Pseudomonas aeruginosa, where S. aureus was the most sensitive organism. Sesame and soyabean oils also showed moderate activity against S. aureus. Higher content of linolenic acid in O. sanctum fixed oil could contribute towards its antibacterial activity. The antibacterial activity combined with anti-inflammatory and analgesic activities of the oil, could make it useful in inflammatory disorder resulting from staphylococcal infection.     

Evaluation and Risk Management by Using Ocimum bacillicum Against Waterborne Pathogens

Food and medicinal plants have been used for centuries against human diseases. The methanolic and aqueous extracts of different parts of Ocimum bacillicum Lam. (Niazboo or Sweet basil) of family Lamiaceae were investigated in vitro for their antibacterial properties against waterborne pathogens. The antibacterial properties of different parts of Ocimum bacillicum samples were assessed against Gram positive and Gram negative bacteria, which were isolated from water samples and identified by the API 20E method. The extracts from leaves and seeds of Ocimum bacillicum showed more antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and E. coli at 37°C than those obtained from shoots, roots, and buds. The lowest minimum inhibitory concentrations and minimum bactericidal concentrations were observed for leaves and seeds as compared to other parts of the plant. No activity of alum was observed against the tested bacterial strains. The seeds of Ocimum bacillicum were associated with higher coagulation activity in comparison to other parts of the plant and were comparable with alum. These results suggest that parts of a plant offer a potential for antimicrobial treatment of drinking water, but needs further exploration.