Vaishali C. Joshi

Constituents of Nelumbo nucifera leaves and their antimalarial and antifungal activity

From the leaves of Nelumbo nucifera (an aquatic plant), one new compound, 24(R)-ethylcholest-6-ene-5α-ol-3-O-β-D-glucopyranoside (1), along with 11 known metabolites (2-12), were isolated and identified by spectroscopic methods including 1D- and 2D NMR. Antifungal activity for (R)-roemerine (3) (IC50/MIC = 4.5/10 μg/mL against Candida albicans) and antimalarial activity for (R)-roemerine (3) and N-methylasimilobine (5) (IC50 = 0.2 and 4.8 μg/mL for the D6 clone, respectively, and 0.4 and 4.8 μg/mL for the W2 clone, respectively) was observed. None of the compounds were cytotoxic to Vero cells up to a concentration of 23.8 μg/mL. NMR data for 10-eicosanol (7) and 7,11,15-trimethyl-2-hexadecanone (10) are presented for the first time. An analysis of the structure-activity relationship shows that the substituents in position C-1 and C-2 of aporphine alkaloids are crucial for the antimalarial activity.

Indolizidine, antiinfective and antiparasitic compounds from Prosopis glandulosa var. glandulosa.

A new potent antiinfective and antiparasitic 2,3-dihydro-1H-indolizinium chloride (1) was isolated from Prosopis glandulosa var. glandulosa. Three additional new (2-4) and one known (5) indolizidines were also isolated, and the dihydrochloride salts of 1-3 (compounds 6, 7, and 8) were prepared. Structures were determined by 1D and 2D NMR and mass spectra. Compound 1 showed potent in vitro antifungal activity against Cryptococcus neoformans and Aspergillus fumigatus (IC(50) values = 0.4 and 3.0 microg/mL, respectively) and antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare (IC(50) values of 0.35 and 0.9 microg/mL, respectively). The remarkable in vitro fungicidal activity of 1-4 against C. neoformans (MFCs = 0.63-1.25 microg/mL) and 2, 3, and 5 against A. fumigatus (MFCs = 0.63-2.5 microg/mL) were similar to amphotericin B, but >2-4-fold more potent than 6-8. Prosopilosidine (1) showed potent in vivo activity at 0.0625 mg/kg/day/ip for 5 days in a murine model of cryptococcosis by eliminating approximately 76% of C. neoformans infection from brain tissue compared to approximately 83% with amphotericin B at 1.5 mg/kg/day. Compounds 1 and 4 exhibited potent activity and high selectivity index (SI) values against chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum, with IC(50) values of 39 and 95 ng/mL and 42 and 120 ng/mL, respectively (chloroquine, IC(50) = 17 and 140 ng/mL). Prosopilosine (1) also showed in vivo antimalarial activity, with an ED(50) value of approximately 2 mg/kg/day/ip against Plasmodium berghei-infected mice after 3 days of treatment.

Composition, Standardization and Chemical Profiling of Banisteriopsis caapi, a Plant for the Treatment of Neurodegenerative Disorders Relevant to Parkinson’s Disease

ETHNOPHARMACOLOGICAL RELEVANCE Banisteriopsis caapi, a woody vine from the Amazonian basin, is popularly known as an ingredient of a sacred drink ayahuasca, widely used throughout the Amazon as a medicinal tea for healing and spiritual exploration. The usefulness of Banisteriopsis caapi has been established for alleviating symptoms of neurological disorders including Parkinsons disease. AIM OF THE STUDY Primary objective of this study was to develop the process for preparing standardized extracts of Banisteriopsis caapi to achieve high potency for inhibition of human monoamine oxidases (MAO) and antioxidant properties. The aqueous extracts prepared from different parts of the plant collected from different geographical locations and seasons were analyzed by HPLC for principal bioactive markers. The extracts were simultaneously tested in vitro for inhibition of human MAOs and antioxidant activity for analysis of correlation between phytochemical composition of the extracts and bioactivities. MATERIALS AND METHODS Reversed-phase HPLC with photodiode array detection was employed to profile the alkaloidal and non-alkaloidal components of the aqueous extract of Banisteriopsis caapi. The Banisteriopsis caapi extracts and standardized compositions were tested in vitro for inhibition of recombinant preparations of human MAO-A and MAO-B. In vitro cell-based assays were employed for evaluation of antioxidant property and mammalian cell cytotoxicity of these preparations. RESULTS Among the different aerial parts, leaves, stems/large branches and stem bark of Banisteriopsis caapi, HPLC analysis revealed that most of the dominant chemical and bioactive markers (1, 2, 5, 7-9) were present in high concentrations in dried bark of large branch. A library of HPLC chromatograms has also been generated as a tool for fingerprinting and authentication of the studied Banisteriopsis caapi species. The correlation between potency of MAO inhibition and antioxidant activity with the content of the main active constituents of the aqueous Banisteriopsis caapi extracts and standardized compositions was established. Phytochemical analysis of regular/commercial Banisteriopsis caapi dried stems, obtained from different sources, showed a similar qualitative HPLC profile, but relatively low content of dominant markers 1, 2, 7, and 9, which led to decreased MAO inhibitory and antioxidant potency compared to Banisteriopsis caapi Da Vine. CONCLUSION The ethnopharmacological use of bark of matured stem/large branch of Banisteriopsis caapi as well as whole matured stem is supported by the results obtained in this investigation. Among various constituents of Banisteriopsis caapi, harmine (7), harmaline (6) and tetrahydroharmine (5) are responsible for MAO-A inhibition, while two major proanthocyanidines, epicatechin (8) and procyanidine B2 (9) produce antioxidant effects. The compounds 1-9 can serve as reliable markers for identification and standardization of Banisteriopsis caapi aerial parts, collected in different seasons and/or from different geographical regions.

Authentication of Stephania tetrandra S. Moore (Fang Ji) and differentiation of its common adulterants using microscopy and HPLC analysis.

Stephania tetrandra S. Moore (Hang Fang Ji) is used in traditional Chinese medicine as a diuretic, an antiphlogistic, and an antirheumatic. The name “fang ji” is applied to at least four different genera of plants, including Aristolochia fangchi Y. C. Wu ex L. D. Chow and S. M. Hwang, Cocculus orbiculatus (L.) DC., Stephania tetrandra S. Moore, and Sinomenium acutum Rehder and E. H. Wilson. Due to similarity in the use of their common names, Stephania tetrandra S. Moore is often confused with Aristolochia fangchi Y. C. Wu ex L. D. Chow and S. M. Hwang, which has potentially dangerous consequences. To aid rapid and easy differentiation between the roots of these four species, so as to avoid possible contamination, detailed macroscopic and microscopic observations were made using stereo-and light-microscopy. The powdered samples were further analyzed using HPLC.

NMR fingerprinting for analysis of hoodia species and hoodia dietary products.

Hoodia gordonii, a succulent plant growing in African arid regions, is used as a botanical dietary supplement for weight loss. The increasing concerns on the quality and safety of Hoodia products call for the needs of more science-based information, as well as objective and efficient tools for inspection. In the present study, NMR fingerprinting and multivariate analysis techniques were applied for the identification, discrimination, and quality analysis of Hoodia plant materials and commercial products. Four Hoodia species, namely H. gordonii (five authenticated samples), H. currorii (one authenticated sample), H. parviflora (three authenticated samples), and H. rushii (one authenticated sample), were investigated; the chemicals and characteristic spectral signals that made most contributions for their differentiations were revealed. With the aid of NMR fingerprint analysis, ten Hoodia products sold on the dietary supplement market were assessed for their chemical composition and quality. The study demonstrated that the NMR fingerprinting approach could be a promising and efficient tool for the authentication of botanicals.

Characterization and pharmacological properties of in vitro propagated clones of Echinacea tennesseensis (Beadle) Small

Tissue culture techniques have been used to establish and maintain a repository of medicinal Echinacea. In vitro clones obtained from hypocotyls of germinated seeds, varied macroscopically, microscopically and exhibited variation in immune enhancing activity. Two in vitro produced clones of Echinacea tennesseensis (Beadle) Small (ETN 03 and ETN 11) were identified as high and low activity based on the activation of human monocytes. Phenotypic analyses of ETN 03 and ETN 11 clones were done using AFLP (Amplified Fragment Length Polymorphism) assay. Results of the AFLP assay revealed that no mutation has occurred during in vitro multiplication, storage, and acclimatization into soil. Plants of ETN 03, ETN 11 clones were cultivated for two growing seasons. Extracts of their dry leaves and roots exhibited immune enhancing activity; however, the variation in activity noticed between clones during micropropagation diminished and was no longer statistically relevant.

Identification and Differentiation between Hoodia gordonii (Masson) Sweet ex Decne., Opuntia ficus indica (L.) P. Miller, and Related Hoodia Species Using Microscopy and PCR

Hoodia gordonii, an appetite suppressant, is used extensively as a botanical dietary supplement. Microscopy and molecular genetic procedures are provided for identification and differentiation between H. gordonii, Opuntia ficus indica, and other related Hoodia species.