Hibiscus Flowers Research Articles

Longevity of Cosmopolitan and Native Australian Drosophila in Ethanol Atmospheres.

The longevity of adults exposed to ethanol vapour over solutions of ethanol in water is increased in Drosophila species that are normally collected by attraction to fermented-fruit baits. These include species of subgenera Drosophila, Dorsilopha, Sophophora and Scaptodrosophila. The increase occurs up to a threshold where ethanol becomes a metabolic cost rather than a benefit. Except for a temperatezone population of D. melanogaster with a threshold of about 12%, the remainder cluster between 1.6 and 5.1%. These latter include several species utilizing resources additional to fruits, in particular various vegetables and flowers. Also included is the specialist species D. buzzatii which exploits the cactus Opuntia as a resource. In contrast, D. (Scaptodrosophila) inornata, a species collected by sweeping in southern temperate rain forests, has a threshold of <1% ethanol, while in D. (Scaptodrosophila) hibisci, which utilizes endemic Hibiscus flowers as a resource, longevity is not increased. The frequency and level of ethanol resource utilization in species not attracted to fermented-fruit baits is an open question. However, it is likely that all species attracted to fermented-fruit baits are able to utilize gaseous ethanol.

Genetic variability of alcohol dehydrogenase among Australian Drosophila species: correlation of ADH biochemical phenotype with ethanol resource utilization.

Alcohol dehydrogenase (ADH) activities, electrophoretic phenotypes, and the extent of ethanol resource utilization are compared for three groups of species distinguishable on ecological criteria: 1) the cosmopolitan species D. melanogaster, a frequent inhabitant of wineries; 2) fruit‐baited species of the typically Australian subgenus Scaptodrosophila: D. lativittata, D. nitidithorax and D. howensis; and 3) Scaptodrosophila species not attracted to fermented‐fruit baits being collected by sweeping in temperate rain forests (D. inornata, D. collessi) or from Hibiscus flowers (D. hibisci). D. melanogaster showed the highest levels of ADH activity and an electrophoretic polymorphism with two active allelic forms, while group 2) species showed intermediate ADH activities and polymorphisms, which were consistent with “high activity” and “low activity” allelic forms in natural populations of these species, and group 3) species showed only “low activity” forms. Ethanol resource utilization follows the same sequence, being 1 > 2 > 3(D. howensis and D. collessi were not tested). Therefore the species considered shown an association of ADH biochemical phenotype, laboratory ethanol utilization, and resources utilized.

Components of the flowers of a hybrid hibiscus

Components of the flowers of a hybrid hibiscus

Anthocyanins of Hibiscus cannabinus

Two anthocyanin glycosides have been isolated from the flowers ofHibiscus cannabinus var. simplex. One of them is a new glycoside, which has been called cannabinin, and the second is the known glycoside myrtillin, this being the first time that it has been isolated from the flowers of Kenaf hemp.

NOTES ON THE BIOLOGY OF A LITHURGINE BEE (HYMENOPTERA: MEGACHILIDAE) IN QUEENSLAND

AbstractNests of Lithurge atratiformis Cockerell, found in rotten branches in south‐eastern Queensland, are described and are similar to those of some other species of the genus. Previous reports of Lithurge building nests of mud appear to be erroneous. Adults of L. atratiformis visit and gather the coarse‐grained pollen of Ipomoea and Hibiscus flowers. Two generations per year are indicated with overwintering occurring in larval form.

Phytochemical arrestants for the leaf-cutting ants,Atta cephalotes(L.) andAcromyrmex octospinosus(Reich), with some notes on the ants' response

Albedo (the inner, white part of the rind) of the grapefruit (Citrus parodisi) and the flowers of the garden hibiscus (Hibiscus rosa-sinensis) were analysed for the presence of chemo-stimulants for the leaf-cutting antsAtta cephalotes(L.) andAcromyrmex octospinosus(Reich). Two distinct types of chemical substances in grapefruit albedo (unabsorbed sapids from a cation-exchange resin I.R. 120, and the total lipid fraction) were significant arrestants forAtta cephalotes, whilst five types of chemical substances (absorbate on the cation-exchange resin I.R. 120, unabsorbed sapids from the same resin, the total lipid fraction, absorbate on a polyamide resin, and neohesperidosides) arrestedAcromyrmex octospinosus. For both ant species, the unabsorbed sapids from the polyamide resin appeared to be the most attractive of the relatively refined fractions. A preliminary analysis showed a similar situation for hibiscus flowers.Both ant species preferred young to older grapefruit leaves. There appears to be a chemical basis for this, and in the case ofA. octospinosusthere was evidence of the existence of repellents in the older leaves and in grapefruit flavedo (the outer, yellow part of the rind).Substantial heterogeneity in preferences was detected in a given nest from day to day, between different nests of the same species, and between the two species. It is suggested that this is attributable to social phenomena evolved by the ants.

A study of the anthocyanins of hibiscus hybrids

The flowers of the hybrid hibiscus of the variety M. Gor'kii were extracted with methanol containing 1% of HCI. The anthoeyanins were precipitated from the extract with a threefold volume of ether. The total anthocyanins were separated by chromatography on a column of cellulose powder in the water-acetic acid-concentrated HCI (82 : 15 : 3) system. Two individual crystalline substances were obtained. After recrystallization from 2 N HCI in ethanol, the first anthoeyanin formed a dark violet microcrystalline powder with a golden tinge having mp 215-217 ° C (decomp.) with the composition C21H21OIICI. 2H20; UV absorption spectrum: kma x 525 m# [i].

Colouring matter of the flowers ofHibiscus vitifolius

The colouring matter of the flower petals ofHibiscus vitifolius consists almost entirely of gossypin along with very small amounts of quercetin. These petals form a very good source of this new and interesting glycoside and eventually of gossypetin also.

The waxy matter of the flowers ofHibiscus sabdariffa andCarthamus tinctorius

The waxy matter isolated from the flowers ofHibiscus sabdariffa by alcohol extraction yielded phytosterolin as the ether-insoluble component. The ether-soluble portion consisted mainly of hydrocarbons having chain lenghts round about C27 along with very small amounts of sitosterol. By the extraction of safflower with carbon tetrachloride was obtained a wax made up mostly of paraffin of chain lenght C29 and near homologues.

Isolation of hibiscitrin from the flowers ofHibiscus sabdariffa: Constitution of Hibiscetin

A new flavonol glycoside has been isolated from the flower petals ofHibiscus sabdariffa, and has been named Hibiscitrin. Its aglycone, Hibiscetin is a hexahydroxy flavonol forming a heptaacetyl derivative on acetylation. When decomposed with boiling 50% alkali, its heptamethyl ether produces trimethyl gallic acid, indicating thereby the existence of hydroxyl groups in 3′, 4′ and 5′ positions in hibiscetin. On oxidation withp-benzoquinone, the pigment yields the corresponding quinone, and hence it should contain two hydroxyl groups in positions 5 and 8. It resembles gossypetin in many of its properties especially the colour changes with alkaline buffer solutions, and also occurs along with it in the flowers. It is, therefore, expected that the benzopyrone part of hibiscetin would be just the same as in gossypetin, and hence it is assigned the structure of 3∶ 5∶ 7∶ 8∶ 3′∶ 4′∶ 5′-heptahydroxy-flavone.

Colouring matter of the flowers ofHibiscus cannabinus: Constitution of Cannabiscetin

The colouring matter of the flower petals ofHibiscus cannabinus consists mostly of the glucoside cannabiscitrin along with small quantities of the corresponding aglucone cannabiscetin. The properties and reactions of these two substances are described along with those of some of their derivatives.

Caracterização antibacteriana e fitoquímica de flores de Hibiscus rosa-sinensis L. (mimo-de-vênus) e Hibiscus syriacus L. (hibisco-da-síria)

Hibiscus rosa-sinensis Hibiscus syriacus and edible flowers are considered and studies demonstrate the potential antibacterial against various microorganisms. This study aimed to analyze the Inhibition of Activity Intensity (IINIB) and the Bacterial Inactivation (IINAB) in vitro of alcoholic extracts of flowers of hibiscus and the relationship with the revealed polyphenols and anthocyanins. We evaluated the front antibacterial action of food interest bacteria, Staphylococcus aureus and Salmonella Enteritidis resulting in significant differences between the mean IINIB/IINAB, S. aureus being the most resistant microorganism strain to H. syriacus and S. Enteritidis was the most sensitive bacteria in both experiments. Concerning the H. rosa-sinensis was effective for both bacteria. The content of phytochemicals compounds found in plants there is a strong positive correlation with the antibacterial activity (r = 0.88), and H. rosa-sinensis obtained antibacterial power greater than H. syriacus, assuming be related to increased amount of polyphenols and anthocyanins detected at first. We conclude that the plants have bactericidal and bacteriostatic studied power may act against bacterial contamination.