Two New Clerodane Diterpenes from Tinospora sagittata
Two new clerodane-type diterpenes, tinosporins C (1) and tinosporins D (2) were isolated from the stems of Tinospora sagittata (Oliv.), together with three known ones, columbin (3), tinophylloloside (4), and tinospinoside D (5). The structures of these compounds were determined on the basis of spectroscopic data interpretation, with that of the absolute configuration of compound 1 was assigned by experimental and calculated ECD spectra. The cytotoxicity and α-glucosidase inhibitory activities of isolated compounds were evaluated in vitro.
Tinospora species: An overview of their modulating effects on the immune system.
ETHNOPHARMACOLOGICAL RELEVANCE
Studies on the effects of natural immunomodulators to heal various diseases related to the immune system have been a growing interest in recent years. Amongst the medicinal plants, Tinospora species (family; Menispermaceae) have been one of the widely investigated plants for their modulating effects on the immune system due to their wide use in ethnomedicine to treat various ailments related to immune-related diseases. However, their ethnopharmacological uses are mainly with limited or without scientific basis.


AIM OF THIS REVIEW
In this article, we have reviewed the literature on the phytochemicals of several Tinospora species, which have shown strong immunomodulatory effects and critically analyzed the reports to provide perspectives and instructions for future research for the plants as a potential source of new immunomodulators for use as medicinal agents or dietary supplements.


MATERIALS AND METHODS
Electronic search on worldwide accepted scientific databases (Google Scholar, Science Direct, SciFinder, Web of Science, PubMed, Wiley Online Library, ACS Publications Today) was performed to compile the relevant information. Some information was obtained from books, database on medicinal plants used in Ayurveda, MSc dissertations and herbal classics books written in various languages.


RESULTS
T. cordifolia, T. crispa, T. sinensis, T. smilacina, T. bakis, and T. sagittata have been reported to possess significant immunomodulatory effects. For a few decades, initiatives in molecular research on the effects of these species on the immune system have been carried out. However, most of the biological and pharmacological studies were carried out using the crude extracts of plants. The bioactive compounds contributing to the bioactivities have not been properly identified, and mechanistic studies to understand the immunomodulatory effects of the plants are limited by many considerations with regard to design, conduct, and interpretation.


CONCLUSION
The plant extracts and their active constituents should be subjected to more detail mechanistic studies, in vivo investigations in various animal models including pharmacokinetic and bioavailability studies, and elaborate toxicity study before submission to clinical trials.
Calculation of Complex Radiant Heat Load From Surrounding Radiator Surface Temperatures
Abstract A method for calculating the radiant heat exchange between an absorber and individual radiating components in its surroundings is reported. Radiator surface temperatures, ambient and absorber temperatures, and configuration factors for radiating components in the surroundings are used in the customary radiant heat exchange formulae. Simplified methods for calculating or estimating configuration factors for radiators of various shapes solely from angles, subtended at the absorber by the radiators are presented. The method has been verified in the laboratory under controlled conditions and has been used to advantage in the field studies. The method has advantages over the globe therometer method in certain applications.