Djaja Doel Soejarto

The Conservation of Medicinal Plants: Global Importance of Medicinal Plants

Introduction Ancient Man is known to have utilized plants as drugs for millennia. Based on current knowledge, at least in the West, we know that extracts of some of these plants are useful in a crude form, i.e. Atropa belladonna Tincture as an antispasmodic, Rauvolfia serpentina roots for hypertension and as a tranquilizer, Papaver somniferum extract or tincture as an analgesic, etc. Further, we know that at least 121 chemical substances of known structure are still extracted from plants that are useful as drugs throughout the world (Anon, 1982a). A large number of plants are used in traditional medical practices, and have been for more than 3000 years, such as in Chinese Traditional Medicine, Ayurvedic Medicine, Unani Medicine, etc., most of which probably exert therapeutic effects and would be proven as such if they were properly evaluated by Western standards. Still further, plants have been employed for centuries by primitive cultures; most of these are less likely to pass the test of modern experimental verification of efficacy. Finally, there are a large number of so-called herbal remedies, mainly sold in health food stores in developed countries, many of which remain to be verified for their real therapeutic effects. Several years ago the World Health Organization made an attempt to identify all medicinal plants that exist in the world. It was admitted that the compilation of names of medicinal plants undoubtedly contained many replicates since botanical verification was not attempted. Further, the list only provided Latin binomials and the countries where the plants were used, but excluded data indicating what the plants were used for. More than 20,000 species were included on this list.

Potential consequence of plant extinction in the United States on the current and future availability of prescription drugs

This paper attempts to answer the question: What is the dollar value that can be placed on a single plant species now growing in the United States, should it become extinct? Based on available botanical and prescription survey data and data on global studies of plants as a source of new drugs for human use, the value of a single species is calculated to be

Potential sweetening agents of plant origin. II. field search for sweet-tastingStevia species

203 million, and the total value of plant species growing in the United States that may become extinct by the year 2000 AD is calculated to be about

Noncariogenic intense natural sweeteners

3,248 billion.

Antifertility effects of gossypol and its impurities on male hamsters

Field work in Paraguay, Peru, Colombia and Mexico, including field organoleptic tests and interviews, was carried out in search of sweet-tasting Stevia species. Results of such tests performed on at least 31 species, as well as ethnobotanical data on 9 species, are presented. The data obtained showed that leaves of no other Stevia species studied possessed a potent sweet taste comparable to that of S. rebaudiana leaves. Since only 15% of the approximately 200 known species in this genus were investigated in this study, it is quite possible that further research may reveal additional sweet-tasting Stevia species.

Isolation and characterization of minor analogues of silvestrol and other constituents from a large-scale re-collection of Aglaia foveolata.

There is a definite relationship between the dietary consumption of sucrose and the incidence of dental caries. Noncaloric sucrose substitutes for use in the sweetening of foods, beverages, and medicines may be either synthetic compounds or natural products. In the United States, four potently sweet artificial sweeteners are approved, namely, saccharin, aspartame, acesulfame potassium, and sucralose. Highly sweet plant constituents are used in Japan and some other countries, including the diterpene glycoside stevioside and the protein thaumatin. Recent progress in a research project oriented towards the discovery and evaluation of novel potentially noncariogenic sweeteners from plants has focused on substances in the sesquiterpenoid, diterpenoid, triterpenoid, steroidal saponin, and proanthocyanidin structural classes. The feasibility of using Mongolian gerbil electrophysiological and behavioral assays to monitor the sweetness of plant extracts, chromatographic fractions, and pure isolates has been investigated. An in vivo cariogenicity study on the commercially available natural sweeteners stevioside and rebaudioside A has been carried out.

Natural anti-HIV agents. Part 2: Litseaverticillol A, a prototypic litseane sesquiterpene from Litsea verticillata

Recent papers reporting on the male antifertility effects of gossypol have been criticized due to the possible influence of impurities on efficacy and toxicity. Our laboratory has prepared purified gossypol and a fraction containing the total impurities. The effects of these two substances and impure gossypol on the fertility of male hamsters was evaluated. Only pure gossypol produced a decrease in fertility after six weeks of dosing. No effects on male fertility were observed in the other treatment groups. A full recovery of fertility in the pure gossypol group was observed four weeks after cessation of treatment. These data support the claim that gossypol is indeed an active antifertility agent for males. It is also clear that the impurities may have the ability to block or decrease the efficacy of gossypol.

Natural anti-HIV agents. Part 3: Litseaverticillols A-H, novel sesquiterpenes from Litsea verticillata

Two new minor silvestrol analogues [2-episilvestrol (1) and 2,5-diepisilvestrol (2)], together with a new 21-norbaccharane-type triterpene (3), two new 3,4-secodammarane triterpenes (4 and 5), and a new eudesmane sesquiterpene (6), as well as nine known compounds, were isolated from a large-scale re-collection of the CHCl(3)-soluble extract of the stem bark of Aglaia foveolata obtained in Kalimantan, Indonesia. The structures of the new compounds were established by interpretation of their spectroscopic data. All of the isolates were tested for cytotoxicity against HT-29 cells. The new silvestrol analogues, 1 and 2, were considerably less active as cytotoxic agents than silvestrol (7) and episilvestrol (5-episilvestrol) (8) against this cell line, showing the importance of the configuration at C-2 in mediating such activity within this compound class. Several of the compounds isolated were also evaluated in a NF-κB (p65) inhibition assay.

Ethnopharmacologic studies. I. Rapid solution to a problem — oral use of Heliopsis longipes — by means of a multidisciplinary approach

Abstract We report herein the first isolation of a novel structural type sesquiterpene designated as ‘litseane’ from the twigs and leaves of Litsea verticillata Hance (Lauraceae). The isolate (litseaverticillol A, 1 ) was obtained as a racemate through bioassay-guided fractionation and found to inhibit the replication of human immunodeficiency virus (HIV) type 1 with an IC 50 value of 5.0 μg/mL (21.4 μM) and a selectivity index of 2.6. Spectroscopic data and a potential biosynthetic pathway are given.

Estrogenic and serotonergic butenolides from the leaves of Piper hispidum Swingle (Piperaceae)

Abstract Bioassay directed-fractionation led to the identification of litseaverticillols A–H ( 1 – 8 ) from the leaves and twigs of Litsea verticillata Hance. These new sesquiterpenes possess a unique skeleton that was recently designated as ‘litseane’. The structures of these compounds were determined by spectroscopic means including 1D and 2D NMR data. Structural configurations were determined by ROESY experiments. Mosher ester reactions and optical rotation measurements established the sesquiterpenes 1 – 8 as racemates. Isolates 1 – 8 inhibited HIV-1 replication in HOG.R5 cells with IC 50 values ranging from 2 to 15xa0μg/ml (8–58xa0μM) while affecting the growth of HOG.R5 at concentrations 2–3-fold higher. Based on this data, structure–activity relationships can be discerned, suggesting compounds of this class are good candidates for analog production.