Biological activities of marine invertebrates extracts from the northeast brazilian coast

This paper reports the in vitro antiproliferative effects, antiprotozoal, anti-herpes and antimicrobial activities of 32 organic extracts of 14 marine sponges and 14 corals collected in northeast Brazilian coast. The ethanolic extracts of the sponges Amphimedon compressa and Tedania ignis, and the acetone extract of Dysidea sp. showed relevant results concerning the antiproliferative effects against A549, HCT-8, and PC-3 cell lines by sulforhodamine B assay, but also low specificity. Concerning the antiprotozoal screening, the ethanolic extract of Amphimedon compressa and the acetone and ethanolic extracts of Dysidea sp. were the most active against Leishmania amazonensis and Trypanosoma cruzi expressing β-galactosidase in THP-1 cells. In the preliminary anti-HSV-1 (KOS strain) screening, the ethanolic extracts of the sponges Amphimedon compressa, Haliclona sp. and Chondrosia collectrix inhibited viral replication by more than 50%. The most promising anti-herpes results were observed for the ethanolic extract of Haliclona sp. showing high selective indices against HSV-1, KOS and 29R strains (SI> 50 and >79, respectively), and HSV-2, 333 strain (IS>108). The results of the antibacterial screening indicated that only the ethanolic extract of Amphimedon compressa exhibited a weak activity against Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli by the disk diffusion method. In view of these results, the extracts of Amphimedon compressa, Tedania ignis and Dysidea sp. were selected for further studies aiming the isolation and identification of the bioactive compounds with antiproliferative and/or antiprotozoal activities. The relevant anti-herpes activity of the ethanolic extract of Haliclona sp. also deserves special attention, and will be further investigated.

Anxiolytic-like, stimulant and neuroprotective effects of Ilex paraguariensis extracts in mice

Yerba-mate (Ilex paraguariensis St. Hil.) is the most used beverage in Latin America with approximately 426 thousand of tons consumed per year. Considering the broad use of this plant, we aimed to investigate the anxiety-like and stimulant activity of both the hydroethanolic (HE) and aqueous (AE) extracts from leaves of I. paraguariensis. Swiss mice were treated with I. paraguariensis HE or AE chronically or acutely, respectively, followed by evaluation in the elevated plus-maze (EPM; anxiety-like paradigm), open field (OF; locomotor activity) or the step-down avoidance task (memory assessment). Following behavioral protocols the brains were collected for evaluation of acetylcholinesterase (AChE) activity ex vivo. Chronic treatment with HE induced an anxiolytic-like effect and increased motor activity besides augmented AChE activity. Additionally, acute treatment with AE prevented the scopolamine-induced memory deficit in the step-down avoidance task. Overall, our results indicate the importance of the I. paraguariensis-induced CNS effects, since it is a widely used nutraceutical. We have reported anxiolytic, stimulant and neuroprotective effects for this plant species. These effects are potentially modulated by the cholinergic system as well as by caffeine.

Glycosylflavonoids from Cecropia pachystachya Trécul are quorum sensing inhibitors

The Cecropia genus is widely distributed in Latin America including at least 60 species, and some of them are commonly used in traditional medicine for the treatment of several diseases. We used Cecropia pachystachya Trécul to search for quorum sensing (QS) inhibitors compounds and found that the aqueous extract of C. pachystachya leaves is a promising source of substances with this activity. Using as biosensor Chromobacterium violaceum ATCC 31532 and Escherichia coli pSB403, the compounds chlorogenic acid (2), isoorientin (3), orientin (4), isovitexin (6), vitexin (7), and rutin (9) were identified as QS inhibitors. None of these compounds inhibited the growth of neither the used biosensors nor the microorganisms Staphylococcus aureus ATCC 23591, Escherichia coli ATCC 25922 and Saccharomyces cerevisiae, used here as growth inhibition controls. Along with the rutin, here we presented for the first time the QS-inhibition potential of the C-glycosyl flavonoids. The prospective of this evidence lead to the use of these compounds as antipathogenic drugs or antifoulants.

In vitro antiherpes effects of a C-glycosylflavonoid-enriched fraction of Cecropia glaziovii Sneth

AIMS

To investigate the in vitro antiherpes effects of the crude aqueous extract obtained from Cecropia glaziovii leaves and their related fractions, the n-butanol fraction (n-BuOH) and the C-glycosylflavonoid-enriched fraction (MeOH(AMB)), and to determine the viral multiplication step(s) upon which this C-glycosylflavonoid-enriched fraction acts.

METHODS AND RESULTS

The antiviral activity was evaluated against human herpes virus types 1 and 2 (HHV-1, HHV-2) by plaque reduction assay. The mode of action of the most active fraction was investigated by a set of assays, and the results demonstrated that MeOH(AMB) fraction exerts anti-herpes action by the reduction of viral infectivity (only against HHV-2); by the inhibition of virus entry into cells; by the inhibition of cell-to-cell virus spread as well as by the impaired levels of envelope proteins of HHV-1. The high-performance liquid chromatography (HPLC)-photo-diode array (PDA) analysis showed that the C-glycosylflavonoids are the major constituents of this fraction.

CONCLUSIONS

These data showed that the MeOH(AMB) fraction has an antiviral activity against HHV types 1 and 2. The C-glycosylflavonoids are the major constituents of this fraction, which suggests that they could be one of the compounds responsible for the detected anti-herpes activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The MeOH(AMB) fraction can be regarded as a phytopharmaceutical candidate for the treatment of herpetic infections.

Passiflora alata and Passiflora edulis spray-dried aqueous extracts inhibit inflammation in mouse model of pleurisy

The aqueous leaves extracts of Passiflora alata (100-300 mg/kg, i.p.) and Passiflora edulis (100-1000 mg/kg, i.p.) possess a significant antiinflammatory activity on carrageenan-induced pleurisy in mice. Treatment with the extracts inhibited leukocyte migration and reduced the formation of exudate. Moreover, a significant inhibition of myeloperoxidase and adenosine-deaminase activities was observed at the doses tested (100 or 250 mg/kg, i.p.). At the same doses, a significant decrease of serum C-reactive protein was observed.

Constituents from leaves of Quillaja brasiliensis

A new abietane diterpene, the 19-O-beta-D-glucopyranoside of 16-hydroxylambertic acid was isolated from the leaves of Quillaja brasiliensis together with a known prosapogenin (3-O-beta-D-glucuronopyranosyl-quillaic acid), quercetin, and rutin. The new compound was identified by chemical and spectroscopic methods.

Triterpenes and saponins from Ilex psammophila

Two new saponins were isolated from the leaves of Ilex psammophila. Their structure was established by chemical and spectroscopic methods as 28-O-beta-D-glucopyranosylester of 20(S)-ilexgenin A ([structure: see text]) and 28-O-beta-D-glucopyranosylester of 20(S)-3beta,19alpha,24-trihydroxyurs-12-ene-23, 28-dioic acid ([structure: see text]).

[Drug use by pregnant women in six Brazilian cities]

OBJECTIVE

To describe drugs used during pregnancy by women attending prenatal clinics of the national public health system (SUS) in Brazilian cities.

METHODS

Using a structured questionnaire, 5,564 pregnant women between the week 21 to 28 who attended prenatal visits of the SUS in six Brazilian cities were interviewed. The interview questions were grouped in "guided use" to cover pain, cramps, nausea, cough, and others, and "guided medicine" to cover vitamins, iron, and fluoride. The Food and Drug Administration gestational risk classification (1991-1995) was applied.

RESULTS

Of a total of 5,564 women, 4,614 (83.8%) used at least one drug during pregnancy, with a total of 9,556 drugs used. The drugs most frequently used were vitamins associated with anti-anemics (33.5%), gastrointestinal drugs (31.3%), analgesics and anti-inflammatory drugs (22.2%), anti-anemics (19.8%), and antibiotics (11.1%). Regarding gestational risk, 3,243 drugs used (34%) belonged to category A risk, 1,923 (22.6%) to category B, 3,798 (39.7%) to category C, 289 (3.0%) to category D, and 55 (0.6%) to category X.

CONCLUSIONS

A large variation in drug use across the cities was observed, especially for anti-anemics and vitamins associated with anti-anemics, revealing the lack of a national consensus regarding the use of these drugs during pregnancy. There was no literature data about safety during pregnancy for 12.9% of the drugs used. This percentage, plus the 26.9% of category C drugs, shows that 40% of the drugs used during pregnancy do not belong to the approved safety categories. However, only 3% of the 9,956 drugs used were clearly contraindicated during pregnancy.

Comparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves

Several species of the genus Passiflora, known in Brazil as "maracujá", have widespread use in folk medicine as sedatives and tranquillizers. The anxiolytic activity of hydroethanol extracts of P. alata and P. edulis leaves was evaluated using the elevated plus-maze test. The extracts presented anxiolytic activity in dosages around 50, 100 and 150 mg/kg.

Experimentally induced cholangiohepatopathy by dosing sheep with fractionated extracts from Brachiaria decumbens

Cholangiohepatopathy was induced in 5 lambs by oral administration of extracts from signal grass (Brachiaria decumbens) in Brazil. Grossly there were pale foci multifocally distributed throughout the hepatic parenchyma in 4 lambs. The microscopic changes, which were similar to those produced by other steroidal sapogenins-containing plants such as Tribulus terrestris and Panicum spp., included multifocal cholangitis, bile duct proliferation, and the presence of crystals in the biliary system.

Antiinflammatory activity of extracts and fractions from the leaves of Gochnatia polymorpha

The aqueous and ethanol extracts from the leaves of Gochnatia polymorpha and further fractions obtained from the latter extract using solvents with increasing polarity, including its aqueous residue and the amino acid, 4-hydroxy-N-methyl-proline were investigated by carrageenin-induced pedal oedema formation. It was shown that the aqueous and ethanol extracts and the ethyl acetate fraction demonstrated significant antiinflammatory activity. The chemical investigation of the latter fraction revealed the presence of caffeic acid, chlorogenic acid, 3-0-methylquercetin, hyperosid and rutin. The amino acid 4-hydroxy-N-methyl-proline, a nonprotein amino acid that has not been reported before in the Asteraceae was isolated as a major compound and identified by spectroscopic methods.

Caffeine and theobromine in epicuticular wax of Ilex paraguariensis A. St.-Hil

Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.

Effect of flavonol derivatives on the carrageenin-induced paw edema in the rat and inhibition of cyclooxygenase-1 and 5-lipoxygenase in vitro

Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chromen-4-one (6), 2-(4-ethoxyphenyl)-3-hydroxy-4H-chromen-4-one (7), 2-(4-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (10), and 2-(3-n-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (11) as well as the trihydroxy derivative 3-hydroxy-2-(3,4,5-trihydroxyphenyl)-4H-chromen-4-one (18) displayed high anti-inflammatory activity in carrageenin-induced rat paw edema. Additionally, the inhibition of enzymes of the arachidonic acid cascade by the derivatives was investigated in vitro. In contrast to the natural compound quercetin, the compounds were more potent inhibiting cyclooxygenase-1 than 5-lipoxygenase except for 3-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5). No correlation between the anti-inflammatory activity in the rat paw edema test and the inhibition of 5-lipoxygenase or cyclooxygenase-1 could be observed. In conclusion, the present results suggest that other effects than inhibition of these enzymes of the arachidonic acid cascade are important for the anti-inflammatory activity of the investigated alkoxyflavonols.

Allergenic sesquiterpene lactones from Eupatorium cannabinum L. and Kaunia rufescens (Lund ex de Candolle)

From Eupatorium cannabinum L., a hitherto unknown alpha-methylene-gamma-butyrolactone, 3 beta-peroxyeucannabinolide, was isolated. This compound and eupatoriopicrin from the same plant showed a weak sensitizing capacity in guinea pigs. 2-oxoludartin and dehydroleucodin, isolated from Kaunia rufescens (syn. Eupatorium rufescens), were strong sensitizers in the same sensitizarian procedure.

Isolation of steroidal sapogenins implicated in experimentally induced cholangiopathy of sheep grazing Brachiaria decumbens in Brazil

As part of an experimental study, crystal-associated cholangiopathy was induced in 9 sheep by grazing pure pastures of Brachiaria decumbens in Brazil. One of these sheep showed characteristic lesions of photosensitization. The analysis of the B decumbens samples by acidic hydrolysis followed by TLC and infrared spectrum revealed diosgenin as the principal sapogenin present in the plant. In the rumen contents samples from the B decumbens-grazing group were identified by TLC, 1H and 13C NMR and EIMS as epismilagenin, episarsasapogenin, and a mixture of smilagenin and sarsasapogenin. In the bile samples from the B decumbens-grazing group, TLC analysis demonstrated 2 compounds similar to epismilagenin and episarsasapogenin. However, by this same method, those compounds were not observed in the rumen contents and bile from 2 sheep which served as control animals. The P chartarum spore counts remained very low during the experimental period.

Triterpenoid glycosides and a triterpene from Ilex brevicuspis

Two saponins and a sapogenin were isolated from the leaves of Ilex brevicuspis. Their structures were established by means of spectroscopic methods as brevicuspisaponin 1 (3-O-alpha-L-arabinopyranosyl-20(S)-19 alpha,24-dihydroxyursolic acid), brevicuspisaponin 2 (3-O-alpha-L-arabinopyranosyl-20(S)-19 alpha,23,24-trihydroxyursolic acid) and 23-methylester of 20(S)-3 beta,19 alpha,24-trihydroxyurs-12-en-23,28-dioic acid.

[Information level about drugs prescribed to ambulatory patients in a university hospital]

Lack of information on medication is one of the main reasons why some 30-50% of patients fail to take their medicines as prescribed. To assess patient knowledge about prescribed drugs, outpatients from an internal medicine clinic in a teaching hospital were interviewed after medical consultation. Patients were asked to identify the name, indication, dosage, administration schedule, duration of treatment, side effects, and precautions. Patients' answers were compared to medical prescription or patients' medical records. Two hundred and sixty-four patients were interviewed, of whom 34% displayed satisfactory knowledge. In 31% of cases the drug name stated was incorrect, while in 19% the reported indication differed from that on the medical records. Dosage and administration schedules stated by patients disagreed with physician's instructions in 19% and 31% of cases, respectively. The results suggest that the majority of outpatients have sufficient knowledge for the safe use of prescribed drugs, under an ideal outpatient setting.

[Drug package inserts and the adequacy of patient's drug information]

OBJECTIVE

To investigate the adequacy of the content and format of the patient information section in package inserts of commonly prescribed drugs at the internal medicine service of a school hospital.

METHODS

Forty eight package inserts were collected from six pharmacies of the city of Porto Alegre in June 1998. The presence of mandatory notification and other information required by Brazilian laws that regulate inserts content was examined.

RESULTS

No one package inserts contained all the notification required by law. Warnings about medication storage and expiration date were the most frequently information found in package inserts analyzed.

CONCLUSION

Important information for the drug user was not presented in package inserts analyzed, limiting the purpose of inserts as an instrument for patient education.

Antiviral activity of south Brazilian medicinal plant extracts

Brazilian plants are potential sources of useful edible and medicinal plants. Hydromethanolic extracts prepared from 54 medicinal plants used in folk medicine to treat infections were screened for antiviral properties against five different viruses (HSV-1, HSV-2, poliovirus type 2, adenovirus type 2 and VSV). Fifty-two percent of the plant extracts exhibited antiviral against one or more tested viruses. More specifically, 42.6% showed activity against HSV-1 (herpes simplex virus type 1), 42.6% against HSV-2 (herpes simplex virus type 2), 26% against poliovirus and 24% against VSV (vesicular stomatitis virus). None of the extracts was active against adenovirus. Trixis praestans (Vell.) Cabr. and Cunila spicata Benth. extracts were further characterized for antiviral activity.

Prescribing practice for antibiotic prophylaxis for 3 commonly performed surgeries in a teaching hospital in Brazil

BACKGROUND

The contribution of antibiotic prophylaxis to reduce surgical wound infection for some procedures is well known. In spite of extensive knowledge about the effectiveness of antibiotic prophylaxis, its administrative regimens are often inappropriate.

METHODS

Antibiotic prophylaxis was evaluated in a university-affiliated community teaching hospital. Data were collected from medical records of patients undergoing cholecystectomy, hysterectomy, and herniorrhaphy during a 9-month observation period. A total of 598 procedures were observed. Data were collected about the patient, the surgery, and the antibiotic prophylaxis.

RESULTS

Based on the existing guidelines, the choice to use the prophylactic antibiotic was correct in 75% of the cases. Of these cases, only 3% of the patients received the recommended regimen according to the proposed procedure. It was verified that antibiotic prophylaxis was performed more frequently in patients undergoing open cholecystectomy than laparoscopic cholecystectomy (P =.004). In 46% of the cholecystectomies, more than 4 doses were administered. In hysterectomy, a single dose was used in 54% of the patients, and the antibiotic was administered preoperatively in 80% of the cases. Prophylactic antibiotics were used in 47% of herniorrhaphies.

CONCLUSION

The surgeons infrequently met the hospital guideline for antibiotic prophylaxis, and compliance varied by type of procedure.

[Non-prescription drugs in Brazil]

In this study we examined the 100 over-the-counter drugs that were most widely sold in Brazil from June 1992 to June 1993. We excluded 23 food products that were classified as medicinal. The sample, which included 77 drugs, was representative of about 67% of all sales in monetary value, and 76.8% of all units sold of the different classes of over-the-counter drugs. The anatomical-therapeutic-chemical (ATC) system was used to classify the various drugs; each class of drugs was also graded according to a scale of its intrinsic value, taking into account effectiveness and risks. Most classes of drugs (91%) showed "little intrinsic value" (that is, were of questionable or no value, of relative value, or unacceptable), and 70% were fixed-dose combinations. Only 10 classes of drugs were included in the Ministry of Health's National Drug List, and four appeared in WHO's list of essential drugs. The therapeutic classes to which the drugs belonged were, in descending order of frequency, for the digestive tract, skin, genitourinary system, musculo-skeletal system, central nervous system, parasitic diseases, respiratory tract, and sensory system. The therapeutic subgroup that commanded the highest sales was that of the non-opiate analgesics and antipyretics. Our results confirm the hypothesis that over-the-counter drugs in Brazil are of poor therapeutic quality and that the use of many such drugs is a source of unnecessary expense for the population. Some of them should not be accessible to individuals who lack current knowledge of their side effects, since 25% of all cases of poisoning in the country are related to self-medication. Modifying the public's perception of the need for taking drugs to relieve their ailments is one approach that may improve their use of medications in the long term.

Prevalence and clinical correlates of unsuccessful use of drugs to induce menstruation

Despite its prohibition, illegal abortion is widely practiced in Brazil, with important adverse health consequences. This report aims to document the prevalence and correlates of the unsuccessful use of drugs to "induce menstrual flow" in a cohort of pregnant Brazilian women. In a cross-sectional study, 6,102 pregnant women between gestation weeks 21 and 28 were interviewed in prenatal clinics of the Brazilian National Health Care System from April 1991 to November 1995. When asked "In order to know if you were pregnant, did you take any medication to induce menstrual flow", 874 (14.4%) responded "yes." The most frequently used drugs were herbal teas (41%), estrogens and/or progestogens (30%), and misoprostol (16%). As demonstrated through logistic regression analysis, independent correlates of such use were unplanned pregnancy (odds ratio [OR] 4.3), low educational attainment (OR 3.3), absence of a husband or partner (OR 1.8), number of children (one or more) (OR 1.5), a history of a previous induced abortion (OR 1.4), and use of oral contraceptives at the time (OR 1.4). Misoprostol use occurred in 2.2% of pregnancies, and showed a very strong association with an unplanned pregnancy (OR 16.0), absence of a husband or partner (OR 3.5), and a history of a previous induced abortion (OR 2.2). It was not associated with a history of menstrual irregularity. In contradistinction, the use of medroxyprogesterone was strongly associated with previous menstrual irregularity (OR = 5.0). The use of drugs and teas, many of which are unknown in terms of fetal risk, in early pregnancy to induce menstrual flow is quite common in women in the Brazilian National Health System. Although the objective of such drug use appears to be varied, analysis of the clinical correlates of use suggest attempted abortion to be the principal aim.

Sesquiterpene peroxides from Senecio selloi and Eupatorium rufescens

Two bisabolane-type sesquiterpenes, zingiberene-3,6-beta-endoperoxide (1) and zingiberene-3,6-alpha-endoperoxide (2) have been isolated from the aerial parts of Senecio selloi and Eupatorium rufescens. Their structures were determined by spectroscopic methods. Both compounds show schizonticidal activity against Plasmodium falciparum (EC50 = 10 microg/ml).

Matesaponin 5, a highly polar saponin from Ilex paraguariensis

The structure of matesaponin 5, a novel saponin isolated from the leaves of the Ilex paraguariensis, was established as ursolic acid-3-0-{beta-D-glucopyranosyl-(1->3)-[alpha-L-rhamnopyranosyl-(1->2)]-alpha-L- arabino pyranosyl}-(28->1)-beta-D-glucopyranosyl-(1->4)-beta-D-glucopyranosyl-(1 ->6)-beta-D-glucopyranosyl] ester.

Triterpenoid saponins from Ilex paraguariensis

The leaves of Ilex paraguariensis have yielded three new saponins named matesaponins 2, 3, and 4 [1-3], which have been characterized by chemical and nmr methods as ursolic acid 3-O-[beta-D-glucopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl- (1-->2)]]-alpha-L-arabinopyranosyl]-(28-->1)-beta-D-glucopyranosyl ester, ursolic acid 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl]-(28-- >1)- [beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]ester, and ursolic acid 3-O-[beta-D-glucopyranosyl-(1-->3)-[alpha-L- rhamnopyranosyl-(1-->2)]]-alpha-L-arabinopyranosyl]-(28-->1)-[beta -D- glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]ester, respectively.

Cucurbitacins as Constituents of Wilbrandia ebracteata

The methanolic extract from the roots of WILBRANDIA EBRACTEATA afforded, in addition to the known dihydrocucurbitacins B and E, dihydroisocucurbitacin B, Cucurbitacins B, D, E, G, H, P, and 22-deoxycucurbi-tacin D, four new compounds whose structures were elucidated as (20 R,24xi)-3)3beta,16alpha,20)24,25-pentahydroxy-10alpha-cucurbit-5-ene-2,11,22-trione (3- EPI-isocucurbitacin G) ( 8), (20 R,22xi)-2beta16a,20,22,25-pentahydroxy-10alpha-cucurbita-5,23 T-diene-3,11-dione ( 13), (20 R)-25-acetoxy-3,16alpha,20-trihydroxy-30- NOR-2-(beta- D-glucopyranosyloxy)-1,2,3,4,5,10-dehydrocucurbit-6-ene-11,22-dione ( 14), and dihydroisocucurbitacin B-3-glucoside ( 16).

Structures and cytotoxic activity relationship of casearins, new clerodane diterpenes from Casearia sylvestris Sw

Casearins G-R, new cytotoxic clerodane diterpenes have been isolated from the leaves of Casearia sylvestris Sw. (Flacourtiaceae). Their structures have been elucidated by spectroscopic methods and chemical conversions, and their structure-activity relationships have been discussed.

New antitumor principles, casearins A-F, for Casearia sylvestris Sw. (Flacourtiaceae)

New antitumor clerodane diterpenes, named casearins A-F, have been isolated from the leaves of Casearia sylvestris Sw. (Flacourtiaceae). These structures have been completely elucidated by two dimensional nuclear magnetic resonance, circular dichroism spectroscopy, X-ray analysis, and chemical evidences.